WO2021083335A1 - Pd-l1结合分子 - Google Patents

Pd-l1结合分子 Download PDF

Info

Publication number
WO2021083335A1
WO2021083335A1 PCT/CN2020/125301 CN2020125301W WO2021083335A1 WO 2021083335 A1 WO2021083335 A1 WO 2021083335A1 CN 2020125301 W CN2020125301 W CN 2020125301W WO 2021083335 A1 WO2021083335 A1 WO 2021083335A1
Authority
WO
WIPO (PCT)
Prior art keywords
seq
amino acid
acid sequence
binding molecule
heavy chain
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2020/125301
Other languages
English (en)
French (fr)
Inventor
孔超
郎国竣
吴琪
刘婵娟
闫闰
闫鑫甜
谈伦嵋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sanyou Biopharmaceuticals Co Ltd
Original Assignee
Sanyou Biopharmaceuticals Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from CN201911044297.0A external-priority patent/CN112745391B/zh
Priority claimed from CN202010765530.0A external-priority patent/CN111848800B/zh
Application filed by Sanyou Biopharmaceuticals Co Ltd filed Critical Sanyou Biopharmaceuticals Co Ltd
Priority to JP2022525333A priority Critical patent/JP7738551B2/ja
Priority to US17/772,323 priority patent/US20230002494A1/en
Priority to EP20882932.5A priority patent/EP4059962A4/en
Priority to KR1020227016606A priority patent/KR20220087488A/ko
Publication of WO2021083335A1 publication Critical patent/WO2021083335A1/zh
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K16/00—Immunoglobulins [IG], e.g. monoclonal or polyclonal antibodies
    • C07K16/18—Immunoglobulins [IG], e.g. monoclonal or polyclonal antibodies against material from animals or humans
    • C07K16/28—Immunoglobulins [IG], e.g. monoclonal or polyclonal antibodies against material from animals or humans against receptors, cell surface antigens or cell surface determinants
    • C07K16/2803—Immunoglobulins [IG], e.g. monoclonal or polyclonal antibodies against material from animals or humans against receptors, cell surface antigens or cell surface determinants against the immunoglobulin superfamily
    • C07K16/2827—Immunoglobulins [IG], e.g. monoclonal or polyclonal antibodies against material from animals or humans against receptors, cell surface antigens or cell surface determinants against the immunoglobulin superfamily against B7 molecules, e.g. CD80, CD86
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P35/00—Antineoplastic agents
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N15/00—Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor
    • C12N15/09—Recombinant DNA-technology
    • C12N15/63—Introduction of foreign genetic material using vectors; Vectors; Use of hosts therefor; Regulation of expression
    • C12N15/79—Vectors or expression systems specially adapted for eukaryotic hosts
    • C12N15/85—Vectors or expression systems specially adapted for eukaryotic hosts for animal cells
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K39/00—Medicinal preparations containing antigens or antibodies
    • A61K2039/505—Medicinal preparations containing antigens or antibodies comprising antibodies
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/20—Immunoglobulins specific features characterized by taxonomic origin
    • C07K2317/22—Immunoglobulins specific features characterized by taxonomic origin from camelids, e.g. camel, llama or dromedary
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/20—Immunoglobulins specific features characterized by taxonomic origin
    • C07K2317/24—Immunoglobulins specific features characterized by taxonomic origin containing regions, domains or residues from different species, e.g. chimeric, humanized or veneered
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/30—Immunoglobulins specific features characterized by aspects of specificity or valency
    • C07K2317/33—Crossreactivity, e.g. for species or epitope, or lack of said crossreactivity
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/50—Immunoglobulins specific features characterized by immunoglobulin fragments
    • C07K2317/52—Constant or Fc region; Isotype
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/50—Immunoglobulins specific features characterized by immunoglobulin fragments
    • C07K2317/56—Immunoglobulins specific features characterized by immunoglobulin fragments variable (Fv) region, i.e. VH and/or VL
    • C07K2317/565—Complementarity determining region [CDR]
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/50—Immunoglobulins specific features characterized by immunoglobulin fragments
    • C07K2317/56—Immunoglobulins specific features characterized by immunoglobulin fragments variable (Fv) region, i.e. VH and/or VL
    • C07K2317/569—Single domain, e.g. dAb, sdAb, VHH, VNAR or nanobody®
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/70—Immunoglobulins specific features characterized by effect upon binding to a cell or to an antigen
    • C07K2317/73—Inducing cell death, e.g. apoptosis, necrosis or inhibition of cell proliferation
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/70—Immunoglobulins specific features characterized by effect upon binding to a cell or to an antigen
    • C07K2317/76—Antagonist effect on antigen, e.g. neutralization or inhibition of binding
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/90—Immunoglobulins specific features characterized by (pharmaco)kinetic aspects or by stability of the immunoglobulin
    • C07K2317/92—Affinity (KD), association rate (Ka), dissociation rate (Kd) or EC50 value

Definitions

  • This application belongs to the field of biotechnology and generally relates to antibodies. More specifically, the present application relates to binding molecules that specifically recognize PD-L1 (for example, single domain antibodies), methods of preparation thereof, and uses thereof.
  • PD-L1 for example, single domain antibodies
  • Immune checkpoints are regulatory molecules that inhibit the immune system, including CTLA-4, PD-1, LAG-3, TIM-3, etc. At present, there are already two immune checkpoints based on CTLA-4 and PD-1. Several antibody drugs are on the market. PD-1 (programmed death 1, programmed death receptor 1) is an important immunosuppressive molecule, which was originally cloned from apoptotic mouse T cell hybridoma 2B4.11. Immunomodulation targeting PD-1 is of great significance for anti-tumor, anti-infection, anti-autoimmune diseases, and organ transplant survival.
  • PD-L1 plays an important role in mediating the escape of tumor cells. It is highly expressed in tumor cells and some antigen-presenting cells, and the amount of expression can be It is induced by a variety of cytokines such as IFN- ⁇ , TGF- ⁇ , etc. In the tumor microenvironment, the up-regulation of PD-L1 expression can directly inhibit the anti-tumor response of T cells through the PD-1 signaling pathway, and mediate the immune escape of tumor cells.
  • Single domain antibody is abbreviated as single domain antibody (sdAb), which is an antibody that contains the variable region domain of a single antibody heavy chain. Similar to IgG antibodies, it can selectively bind to specific antigens, but the molecular weight of single domain antibodies is much smaller than that of IgG antibodies.
  • the first single domain antibody is modified from heavy chain antibodies found in camelid animals (Hamers-Casterman C, Atarhouch T, Muyldermans S, Robinson G, Hamers C, Songa EB, Bendahman N, Hamers R (1993) Naturally occurring antibodies devoid of light chains. Nature 363(6428): 446-448.); the heavy chain antibodies found in these camelids are also called VHH fragments.
  • sdAb single domain antibody
  • Single domain antibodies have many advantages. For example, they have high solubility, good thermal stability and tissue permeability. Some single-domain antibodies can also withstand the degradation of papain due to the presence of intramolecular disulfide bonds; in addition, single-domain antibodies can be used in yeast, It is produced in a variety of expression hosts such as plants and mammalian cells, and the expression level is high, making it extremely cost-effective. (Harmsen MM, De Haard HJ (2007) Properties, production, and applications of camelid single-domain antibody fragments. Appl Microbiol Biotechnol 77(1): 13-22.). With its many advantages, single-domain antibodies have good application prospects in various biotechnology and medical fields. At present, Ablynx's first single-domain antibody drug has been approved for marketing.
  • the purpose of the present invention is to provide a new PD-L1 binding molecule, specifically, to provide a new single domain antibody that specifically recognizes PD-L1.
  • the PD-L1 binding molecule of the present invention has lower toxic and side effects and better clinical efficacy, and can treat cancer more effectively.
  • the present invention provides a binding molecule that specifically recognizes PD-L1, specifically a single domain antibody that specifically recognizes PD-L1.
  • the single domain antibody is also called PD-L1 single domain antibody, PD-L1 antibody in the form of Nanobody, PD-L1 Nanobody or PD-L1 VHH antibody hereinafter, and the above terms can be used interchangeably.
  • the application also provides methods for constructing and screening the PD-L1 binding molecules, nucleic acid molecules encoding the PD-L1 binding molecules, vectors and host cells for expressing the PD-L1 binding molecules, and containing the PD-L1 A composition or kit of binding molecules.
  • the PD-L1 binding molecule of the present application can treat a variety of cancers by regulating the immune system, and therefore can be used to prepare drugs for treating cancer.
  • the present invention provides the PD-L1 antibody in the form of a nanobody and its derivative molecules after humanization or affinity maturation. While maintaining the advantages of high affinity, low molecular weight, etc., the immunogenicity is modified to improve the preparation of drugs. Sex, has a great therapeutic advantage.
  • the present invention provides an isolated PD-L1 binding molecule that specifically binds to PD-L1 and comprises a heavy chain variable region, wherein the heavy chain variable region comprises:
  • CDR1 comprising an amino acid sequence having at least 80%, 85%, 90%, 95% or 99% identity with SEQ ID NO:1; or
  • CDR1 comprising an amino acid sequence with no more than 2 (such as 0, 1, 2) amino acid additions, deletions, and/or substitutions compared with SEQ ID NO: 1;
  • CDR2 comprising the amino acid sequence shown in SEQ ID NO: 2;
  • CDR2 comprising an amino acid sequence that is at least 80%, 85%, 90%, 95% or 99% identical to SEQ ID NO: 2; or
  • CDR3 comprising the amino acid sequence shown in SEQ ID NO: 3 or 12;
  • CDR3 comprising an amino acid sequence having at least 80%, 85%, 90%, 95% or 99% identity with SEQ ID NO: 3 or 12; or
  • a CDR3 comprising an amino acid sequence with no more than 2 (such as 0, 1, 2) amino acid additions, deletions and/or substitutions compared with SEQ ID NO: 3 or 12.
  • the PD-L1 binding molecule comprises a heavy chain variable region, the heavy chain variable region comprising:
  • CDR1 represented by the formula RTDSNIX 1 GMH, wherein X 1 is H, F or N;
  • CDR2 represented by the formula TIFIDX 2 NTX 3 , wherein X 2 is G, L or A, and X 3 is I or L;
  • the PD-L1 binding molecule comprises a heavy chain variable region, the heavy chain variable region comprising:
  • CDR2 comprising SEQ ID NO: 2 or consisting of SEQ ID NO: 2;
  • the PD-L1 binding molecule comprises a heavy chain variable region, the heavy chain variable region comprising:
  • CDR2 comprising SEQ ID NO: 5 or consisting of SEQ ID NO: 5;
  • the PD-L1 binding molecule comprises a heavy chain variable region, the heavy chain variable region comprising:
  • CDR2 comprising SEQ ID NO: 7 or consisting of SEQ ID NO: 7;
  • the PD-L1 binding molecule comprises a heavy chain variable region, the heavy chain variable region comprising:
  • CDR2 comprising SEQ ID NO: 8 or consisting of SEQ ID NO: 8;
  • the PD-L1 binding molecule comprises a heavy chain variable region, the heavy chain variable region comprising:
  • CDR2 comprising SEQ ID NO: 11 or consisting of SEQ ID NO: 11;
  • the PD-L1 binding molecule comprises a heavy chain variable region, the heavy chain variable region comprising:
  • CDR2 comprising SEQ ID NO: 5 or consisting of SEQ ID NO: 5;
  • the PD-L1 binding molecule comprises a heavy chain variable region, the heavy chain variable region comprising:
  • CDR2 comprising SEQ ID NO: 15 or consisting of SEQ ID NO: 15;
  • the PD-L1 binding molecule comprises a heavy chain variable region, the heavy chain variable region comprising:
  • CDR2 comprising SEQ ID NO: 17 or consisting of SEQ ID NO: 17;
  • the PD-L1 binding molecule comprises a heavy chain variable region, the heavy chain variable region comprising:
  • CDR2 comprising SEQ ID NO: 19 or consisting of SEQ ID NO: 19;
  • the PD-L1 binding molecule comprises a heavy chain variable region, the heavy chain variable region comprising:
  • CDR2 comprising SEQ ID NO: 5 or consisting of SEQ ID NO: 5;
  • the present invention provides an isolated PD-L1 binding molecule that specifically binds PD-L1 and comprises a heavy chain variable region, wherein the heavy chain variable region comprises:
  • CDR2 comprising SEQ ID NO: 22 or consisting of SEQ ID NO: 22;
  • the present invention provides an isolated PD-L1 binding molecule that specifically binds PD-L1 and comprises a heavy chain variable region, wherein the heavy chain variable region comprises:
  • CDR2 comprising SEQ ID NO: 25 or consisting of SEQ ID NO: 25;
  • the present invention provides an isolated PD-L1 binding molecule that specifically binds PD-L1 and comprises a heavy chain variable region, wherein the heavy chain variable region comprises:
  • CDR2 comprising SEQ ID NO: 27 or consisting of SEQ ID NO: 27;
  • the present invention provides an isolated PD-L1 binding molecule that specifically binds PD-L1 and comprises a heavy chain variable region, wherein the heavy chain variable region comprises:
  • CDR2 comprising SEQ ID NO: 29 or consisting of SEQ ID NO: 29;
  • the present invention provides an isolated PD-L1 binding molecule that specifically binds PD-L1 and comprises a heavy chain variable region, wherein the heavy chain variable region comprises:
  • CDR2 comprising SEQ ID NO: 31 or consisting of SEQ ID NO: 31;
  • the present invention provides an isolated PD-L1 binding molecule that specifically binds to PD-L1 and comprises a heavy chain variable region, wherein the heavy chain variable region comprises SEQ ID NO: 36-52 Any one of the three CDRs in the amino acid sequence of the variable region of the heavy chain shown.
  • the heavy chain variable region further includes an FR region, and the FR region includes FR1, FR2, FR3, and FR4, and is combined with CDR1, CDR2 and CDR3 are arranged at intervals on the heavy chain variable region to form a structure of FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4 from N-terminus to C-terminus.
  • the FR region comprises:
  • FR1 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 53; or
  • An FR1 comprising an amino acid sequence with no more than 2 (such as 0, 1, 2) amino acid additions, deletions and/or substitutions compared with SEQ ID NO: 53;
  • FR2 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 54; or
  • An FR2 comprising an amino acid sequence with no more than 2 (such as 0, 1, 2) amino acid additions, deletions and/or substitutions compared with SEQ ID NO: 54;
  • FR3 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 55; or
  • FR4 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 56; or
  • An FR4 comprising an amino acid sequence with no more than 2 (such as 0, 1, 2) amino acid additions, deletions, and/or substitutions compared with SEQ ID NO: 56.
  • the FR region comprises:
  • FR1 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 57; or
  • An FR1 comprising an amino acid sequence with no more than 2 (such as 0, 1, 2) amino acid additions, deletions and/or substitutions compared with SEQ ID NO: 57;
  • FR2 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 58; or
  • FR2 comprising an amino acid sequence with no more than 2 (such as 0, 1, 2) amino acid additions, deletions and/or substitutions compared with SEQ ID NO: 58;
  • FR3 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 59; or
  • FR4 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 60; or
  • the FR region comprises:
  • FR1 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 61; or
  • FR2 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 58; or
  • FR2 comprising an amino acid sequence with no more than 2 (such as 0, 1, 2) amino acid additions, deletions and/or substitutions compared with SEQ ID NO: 58;
  • FR3 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 59; or
  • FR4 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 60; or
  • the heavy chain variable region comprises the amino acid sequence shown in any one of SEQ ID NO: 36-52 or is defined by SEQ ID NO. : Composition of the amino acid sequence shown in any one of 36-52.
  • the heavy chain variable region comprises at least 80% of the amino acid sequence shown in any one of SEQ ID NO: 36-52 , 85%, 90%, 95%, or 99% identity and retain the ability to specifically bind to PD-L1.
  • the heavy chain variable region includes an amino acid sequence that has an amino acid sequence shown in any one of SEQ ID NO: 36-52. Addition, deletion, and/or substitution (for example, conservative substitution) of one or more amino acids and an amino acid sequence that retains the ability to specifically bind to PD-L1.
  • the isolated PD-L1 binding molecule of the present invention is a camelid-derived antibody, a humanized antibody, an affinity matured antibody, or a drug-engineered molecule.
  • the isolated PD-L1 binding molecules of the present invention are single domain antibodies or antigen-binding fragments thereof. Therefore, the present invention also provides PD-L1 single domain antibodies in the form of isolated Nanobodies.
  • the heavy chain variable region of the isolated PD-L1 binding molecule of the present invention can be fused to another molecule selected from the Fc domain of an immunoglobulin (eg IgG), an antibody , Antigen-binding fragments of antibodies, antibody-drug conjugates, antibody-like molecules, antigen-binding fragments of antibody-like molecules, or fluorescent proteins.
  • an immunoglobulin eg IgG
  • an antibody Antigen-binding fragments of antibodies, antibody-drug conjugates, antibody-like molecules, antigen-binding fragments of antibody-like molecules, or fluorescent proteins.
  • the PD-L1 binding molecule is fused to the Fc domain of human IgG (such as human IgG1 or human IgG4).
  • the present invention provides an isolated nucleic acid molecule comprising a nucleotide sequence encoding the isolated PD-L1 binding molecule of the present invention.
  • the present invention provides a vector comprising a nucleic acid molecule containing a nucleotide sequence encoding the isolated PD-L1 binding molecule of the present invention.
  • the present invention provides a host cell comprising a nucleic acid molecule containing a nucleotide sequence encoding the isolated PD-L1 binding molecule of the present invention or a vector of the present invention.
  • the present invention provides a pharmaceutical composition comprising the PD-L1 binding molecule of the present invention and a pharmaceutically acceptable carrier.
  • the pharmaceutical composition comprises the PD-L1 single domain antibody or antigen-binding fragment thereof of the present invention and a pharmaceutically acceptable carrier.
  • the present invention provides a method for preparing the PD-L1 binding molecule of the present invention, the method comprising the following steps:
  • the present invention relates to a method of modulating the immune response of a subject, which comprises administering a PD-L1 binding molecule as disclosed herein to the subject so that the immune response in the subject is modulated.
  • the subject is a human or mammal suffering from a disease associated with PD-L1.
  • the subject may suffer from, but not limited to, the following diseases: renal cell carcinoma, non-small cell lung cancer, bladder cancer, urothelial carcinoma, microsatellite unstable solid tumors, and the like.
  • the present invention relates to a method for the treatment or prevention of PD-L1 related diseases, which includes giving a patient suffering from the PD-L1 related disease or the patient suffering from the PD-L1 related disease Disease-prone subjects administer an effective amount of the PD-L1 binding molecule as disclosed herein, or administer the PD-L1 single domain antibody or antigen-binding fragment thereof as disclosed herein, or administer an effective amount of the PD-L1 binding molecule as disclosed herein
  • the present invention relates to methods of treating any disease or condition that can be ameliorated, slowed, inhibited, or prevented by eliminating, inhibiting, or reducing PD-L1 activity.
  • the method of the present invention also relates to a method of treating or preventing tumors by combination therapy, the method comprising administering to the subject an effective amount of the PD-L1 binding molecule described herein, the PD-L1 single domain antibody Or its antigen-binding fragment and one or more other drugs.
  • the method disclosed herein further comprises co-administering an effective amount of a second drug to the subject, wherein the PD-L1 binding molecule or PD-L1 single domain antibody or antigen-binding fragment thereof disclosed herein is the first drug.
  • the second drug is a chemotherapeutic agent, a radiotherapy agent or a biomacromolecule drug used to treat diseases related to PD-L1.
  • the biomacromolecule drug is, for example, various monoclonal antibody drugs that attack tumor cells through T cell recognition, such as rituximab, cetuximab, and trastuzumab.
  • the expression "second drug” as used herein does not mean that it refers to the only drug other than the first drug. Therefore, the second drug need not be a drug, but may constitute or contain more than one such drug.
  • the subject, patient or individual is a mammal, for example, a mouse or a human, preferably a human.
  • the present invention relates to the use of the PD-L1 binding molecule as disclosed herein in the preparation of a medicament for the treatment or prevention of diseases related to PD-L1.
  • the present invention relates to the use of the PD-L1 single domain antibody or antigen-binding fragment thereof as disclosed herein in the preparation of a medicament for the treatment or prevention of diseases related to PD-L1.
  • the disease associated with PD-L1 is selected from, but not limited to, renal cell carcinoma, non-small cell lung cancer, bladder cancer, urothelial carcinoma, microsatellite unstable solid tumors, and the like.
  • the present invention relates to kits or devices and related methods using PD-L1 binding molecules, PD-L1 single domain antibodies or antigen-binding fragments thereof as disclosed herein, and pharmaceutical compositions as disclosed herein, It can be used to treat diseases related to PD-L1, for example, cancer.
  • the present invention preferably provides a product that can be used to treat such disorders, which comprises a container containing a PD-L1 binding molecule, a PD-L1 single domain antibody or an antigen-binding fragment thereof as disclosed herein, and a container for use as disclosed herein.
  • the disclosed PD-L1 single domain antibodies or antigen-binding fragments thereof are used to treat, ameliorate or prevent PD-L1 related diseases or their progress or recurrence.
  • the invention also encompasses any combination of any of the embodiments described herein. Any embodiment described herein or any combination thereof is applicable to any and all PD-L1 binding molecules, PD-L1 single domain antibodies or antigen-binding fragments thereof, methods and uses of the invention described herein.
  • Figure 1 shows the results of binding affinity screening of VHH antibody lysate samples that bind PD-L1.
  • Figure 2 shows the results of blocking experiment screening of anti-PD-L1 candidate antibody molecules.
  • Figure 3 shows the results of the cell binding experiments of candidate antibody molecules: (A) isotype control, (B) NB22D-21, (C) NB22gb-10, (D) positive control KN035.
  • Figure 4 shows the experimental verification results of the specific binding reaction of the NB22D-21 molecule.
  • Figure 5 shows the verification results of the mixed lymphocyte reaction experiment of the NB22D-21 molecule.
  • Figure 6 shows the verification results of the binding experiments of the NB22D-21 molecule and its humanized derivative molecules.
  • Figure 7 shows the results of the human-mouse cross-reaction experiment of the NB22D-21 molecule and its humanized derivative molecules.
  • Figure 8 shows the flow peak diagram results of the human-mouse cross-reaction experiment of the humanized derivative molecule NB22D-21-huVH1: (A) control molecule KN035, (B) NB22D-21-huVH1.
  • Figure 9 shows the results of binding and blocking experiments of the NB22D-21 molecule and its humanized modified molecule.
  • Figure 10 shows the results of the affinity detection of the affinity matured molecule on PD-L1-CHO.
  • Figure 11 shows that the affinity matured molecule blocks the binding of PD-1 to PD-L1-CHO cells.
  • Figure 12 shows the second affinity detection of affinity maturation molecules binding to human PD-L1-CHO cells.
  • Figure 13 shows the detection of the second affinity maturation molecule blocking PD-1 binding to human PD-L1-CHO cells.
  • Figure 14 shows the detection of the second affinity maturation molecule binding to murine PD-L1 cells.
  • Figure 15 shows the blocking activity on PD-L1-CHO of the modified molecule showing druggability, in which the isotype control (isotype) is human IgG1.
  • Figure 16 shows the effect of the modified molecules with drug-like properties on the secretion of IFN- ⁇ (A) and IL-2 (B) in the mixed lymphocyte reaction.
  • Figure 17 shows a sequence alignment of candidate antibody molecules, in which the CDR sequences are boxed.
  • antibody is used in the broadest sense herein and encompasses a variety of antibody structures, including but not limited to monoclonal antibodies, polyclonal antibodies, multispecific antibodies (e.g., bispecific antibodies), and antibody fragments, as long as they It suffices to show the desired antigen-binding activity.
  • Intact antibodies will generally contain at least two full-length heavy chains and two full-length light chains, but may include fewer chains in some cases, for example, antibodies naturally occurring in camelids may contain only heavy chains.
  • antigen-binding portion refers to a portion that specifically binds to a target antigen.
  • the term includes antibodies and other natural molecules (e.g., receptors, ligands) or synthetic molecules (e.g., DARPin) that can specifically bind to the target antigen.
  • the antigen-binding portion of the antibody of the invention is an antibody fragment.
  • full-length antibody “intact antibody” and “whole antibody” are used interchangeably herein to refer to an antibody that has a structure that is substantially similar to the structure of a natural antibody or has a weight containing an Fc region. chain.
  • the term "monoclonal antibody” or “monoclonal antibody composition” refers to a preparation of antibody molecules having a single amino acid composition, and does not refer to the method by which it is produced. Monoclonal antibodies or antigen-binding fragments thereof can be produced, for example, by hybridoma technology, recombinant technology, phage display technology, synthetic technology such as CDR grafting, or a combination of such or other techniques known in the art.
  • PD-1 refers to a programmed cell death protein, which belongs to the immunoglobulin superfamily and functions as a co-inhibitory receptor to negatively regulate the immune system.
  • PD-1 is a member of the CD28/CTLA-4 family and has two known ligands, including PD-L1 and PD-L2.
  • Alternative names or synonyms for PD-1 include PDCD1, PD1, CD279, and SLEB2.
  • the representative amino acid sequence of human PD-1 is disclosed under NCBI accession number: NP_005009.2, and the representative nucleic acid sequence encoding human PD-1 is shown under NCBI accession number NM_005018.3.
  • PD-LI programmed cell death ligand 1
  • PD-L1 programmed cell death ligand 1
  • Alternative names or synonyms for PD-L1 include PDCD1L1, PDL1, B7H1, CD274, and B7-H.
  • the representative amino acid sequence of human PD-L1 is disclosed in NCBI accession number NP_054862.1, and the representative nucleic acid sequence encoding human PD-L1 is shown under NCBI accession number: NM_014143.4.
  • PD-L1 is expressed in the placenta, spleen, lymph nodes, thymus, heart, and fetal liver, and is also found in many tumors or cancer cells. PD-L1 binds to its receptor PD-1 or B7-1, which is expressed on activated T cells, B cells, and bone marrow cells. The binding of PD-L1 and its receptor induces signal transduction to inhibit TCR-mediated cytokine production and activation of T cell proliferation. Therefore, PD-L1 plays a major role in suppressing the immune system during specific events (eg, pregnancy, autoimmune diseases, tissue allografts), and is believed to allow tumors or cancer cells to bypass immune checkpoints and evade immune responses.
  • specific events eg, pregnancy, autoimmune diseases, tissue allografts
  • binding and “specific binding” refer to the binding of an antibody or antigen-binding portion to an epitope in an in vitro assay, preferably in a bio-optical interferometry (ForteBio) using purified wild-type antigen.
  • FormeBio bio-optical interferometry
  • the antibody or antigen-binding portion when the antibody or antigen-binding portion preferably recognizes its target antigen in a complex mixture of proteins and/or macromolecules, the antibody or antigen-binding portion is referred to as specifically binding the antigen.
  • antibodies are divided into “classes”: IgA, IgD, IgE, IgG and IgM, and several of these classes can be further divided into subclasses, such as IgG1, IgG2, IgG3 And IgG4, IgA1 and IgA2.
  • the heavy chain constant regions corresponding to different antibody classes are called [image] ⁇ , ⁇ , ⁇ , and ⁇ , respectively.
  • the light chain constant regions (CL) that can be found in all five antibody classes are called kappa and lambda.
  • variable and constant regions are connected by a "J" region of about 12 or more amino acids, and the heavy chain also includes a "D” region of about 10 or more amino acids.
  • J variable and constant regions
  • D variable region of about 10 or more amino acids.
  • variable region refers to the domain of the heavy or light chain of an antibody that participates in the binding of an antibody to an antigen.
  • the variable domains of the heavy and light chains of natural antibodies usually have similar structures, where each domain contains four conserved framework regions (FR) and three complementarity determining regions (CDR) (see, for example, Kindt et al. Kuby Immunology, 6 th ed., WH Freeman and Co. 91 page (2007)).
  • FR conserved framework regions
  • CDR complementarity determining regions
  • a single VH or VL domain may be sufficient to give antigen binding specificity.
  • VH or VL domains from antibodies that bind to a specific antigen can be used to isolate antibodies that bind to the antigen to screen libraries of complementary VL or VH domains, respectively.
  • FR and CDR in this disclosure are divided according to the AbM standard, but it must be pointed out that the CDR in this disclosure is not limited to the way of dividing AbM, it can also be any other conventional division in the field. Ways, such as Chothia, Martin, Kabat, AHo and IMGT, etc. can also be divided.
  • Variable regions usually exhibit the same general structure of relatively conserved framework regions (FR) connected by three hypervariable regions, which are also referred to as complementarity determining regions or CDRs.
  • the CDRs from the two chains of each pair are usually aligned by the framework regions, which allow the antibody to bind to a specific epitope.
  • the variable regions of the two light and heavy chains usually comprise the domains FR1, CDR1, FR2, CDR2, FR3, CDR3, and FR4 from N-terminus to C-terminus.
  • Antibody fragment refers to a molecule that is different from a whole antibody, which comprises a part of the whole antibody that binds to the antigen to which the whole antibody binds.
  • Bind refers to the strength of the sum of all non-covalent interactions between a single binding site of a molecule (such as an antibody) and its binding partner (such as an antigen). Unless otherwise specified, as used herein, "binding affinity” refers to the intrinsic binding affinity that reflects a 1:1 interaction between members of a binding pair (eg, antibody and antigen). The affinity of a molecule X to its partner Y can usually be expressed by the dissociation constant (Kd). Affinity can be measured by common methods known in the art, including those known in the prior art and those described herein.
  • EC 50 also referred to as “EC50” means the concentration inducing 50% of the drug response between the baseline and maximum, an antibody or agent after a certain exposure time.
  • the unit of EC 50 is "nM”.
  • Human antibody refers to an antibody having an amino acid sequence that corresponds to the amino acid sequence of an antibody produced by human or human cells or derived from a non-human source, which utilizes a human antibody library or other human antibodies Coding sequence. This definition of human antibody specifically excludes humanized antibodies that contain non-human antigen-binding residues.
  • Human consensus framework refers to a framework that represents the most frequently occurring amino acid residues in the selection of human immunoglobulin VL or VH framework sequences. Generally speaking, the choice of human immunoglobulin VL or VH sequence is selected from the subtypes of variable domain sequences. Generally speaking, the subtype of this sequence is the subtype in Kabat et al., Sequences of Proteins of Immunological Interest, Fifth Edition, NIH Publication 91-3242, Bethesda MD (1991), Volume 1-3. In one embodiment, for VL, the subtype is subtype ⁇ I as in Kabat et al. (see above). In one embodiment, for VH, the subtype is subtype III as in Kabat et al. (see above).
  • a “humanized” antibody refers to a chimeric antibody comprising amino acid residues derived from non-human HVR and amino acid residues derived from human FR.
  • a humanized antibody will comprise substantially all of at least one, and usually two variable domains, wherein all or substantially all of the HVR (e.g., CDR) corresponds to those of the non-human antibody, and all Or substantially all FRs correspond to those of human antibodies.
  • the humanized antibody optionally may comprise at least a portion of the constant region of an antibody derived from a human antibody.
  • a "humanized form" of an antibody (e.g., a non-human antibody) refers to an antibody that has been humanized.
  • conservative substitution refers to the substitution of an amino acid by another amino acid in the same category, for example, an acidic amino acid is replaced by another acidic amino acid, a basic amino acid is replaced by another basic amino acid, or a neutral amino acid is replaced by another Neutral amino acid substitution. Exemplary substitutions are shown in Table D below:
  • Amino acids can be grouped according to the properties of common side chains:
  • Non-conservative substitutions require the exchange of members of one of these categories for another.
  • substitution variant includes the substitution of one or more hypervariable region residues of the parent antibody (e.g., a humanized antibody).
  • parent antibody e.g., a humanized antibody
  • one or more variants selected for further research have certain improvements (e.g., improvements) in biological properties relative to the parent antibody (e.g., increased affinity, decreased immunogenicity), and /Or will have specific biological properties that the parent antibody essentially retains.
  • An exemplary substitution variant is an affinity matured antibody, which can be conveniently produced, for example, using phage-based affinity maturation techniques, such as those described herein.
  • one or more HVR residues are mutated, and the variant antibody is displayed on the phage and screened for a specific biological activity (for example, binding affinity).
  • the "percent (%) amino acid sequence identity" relative to the reference polypeptide sequence is defined as when the sequence is aligned (and gaps are introduced when necessary) to obtain the maximum percent sequence identity, and any conservative substitutions are not considered After being part of sequence identity, the percentage of amino acid residues in the candidate sequence that are identical to those in the reference polypeptide sequence.
  • sequence alignment can be used for sequence alignment to determine percent amino acid sequence identity, for example, using publicly available computer software such as BLAST, BLAST-2, ALIGN, or MEGALIGN (DNASTAR) software.
  • Those skilled in the art can determine the appropriate parameters for the measurement alignment, including any algorithm required to obtain the maximum alignment over the entire length of the sequence being compared. When referring to percentages of sequence identity in this application, unless otherwise specified, these percentages are calculated relative to the full length of the longer sequence. Full-length calculations relative to longer sequences are applicable to both nucleic acid sequences and polypeptide sequences.
  • effective amount and “therapeutically effective amount” refer to the amount or dose of the antibody or antigen-binding fragment of the present invention, which, after being administered to a patient in single or multiple doses, produces the desired effect in the treated subject, and this includes receiving Improvement of the subject’s symptoms (for example, improvement of one or more symptoms) and/or delay of the progression of symptoms, etc.
  • Effective amount and “therapeutically effective amount” can also refer to an amount sufficient to reduce PD-L1 signaling.
  • the effective amount can be easily determined by the attending physician as a person skilled in the art by considering various factors such as the species of mammal; its size, age and general health; the specific disease involved; the degree or severity of the disease; The response of the individual patient; the specific antibody administered; the mode of administration; the bioavailability characteristics of the administered formulation; the selected dosing regimen; and the use of any concomitant therapy.
  • blocking means to reduce PD-L1 signal transmission in the presence of the antibody of the present invention.
  • PD-L1 mediated signal transmission blocking means that the PD-L1 signal transmission level in the presence of the PD-L1 single domain antibody of the present invention is lower than the control level of PD-L1 (that is, the PD-L1 signal transmission level in the absence of the antibody) ), the reduction is greater than or equal to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99% or 100%.
  • a variety of standard techniques can be used to measure the level of PD-L1 signaling, such as, as a non-limiting example, measuring downstream gene activation and/or a luciferase reporter test in response to PD-L1 activation.
  • assays can be used to measure the level of PD-L1 signaling, including, for example, commercially available kits.
  • host cell refers to cells into which exogenous nucleic acid is introduced, including the progeny of such cells.
  • Host cells include “transformants” and “transformed cells”, which include primary transformed cells and progeny derived therefrom, regardless of the number of passages.
  • the offspring may not be exactly the same as the parent cell in nucleic acid content, but may contain mutations.
  • the progeny of mutants having the same function or biological activity as those screened or selected in the initially transformed cells are included herein.
  • vector when used herein refers to a nucleic acid molecule capable of multiplying another nucleic acid to which it is linked.
  • the term includes vectors that are self-replicating nucleic acid structures as well as vectors that are incorporated into the genome of a host cell into which it has been introduced. Some vectors can direct the expression of nucleic acids to which they are operably linked. Such vectors are referred to herein as "expression vectors”.
  • “Individual” or “subject” includes mammals. Mammals include, but are not limited to, domestic animals (e.g., cattle, sheep, cats, dogs, and horses), primates (e.g., human and non-human primates such as monkeys), rabbits, alpacas, and rodents Animals (e.g., mice and rats). In some embodiments, the individual or subject is a human.
  • Isolated PD-L1 binding molecules of the present invention may be a single domain antibody or antigen-binding fragment thereof.
  • the present invention provides isolated PD-L1 single domain antibodies or antigen-binding fragments thereof, which can specifically bind to PD-L1.
  • CDR1 comprising an amino acid sequence having at least 80%, 85%, 90%, 95% or 99% identity with SEQ ID NO:1; or
  • CDR1 comprising an amino acid sequence with no more than 2 (such as 0, 1, 2) amino acid additions, deletions, and/or substitutions compared with SEQ ID NO: 1;
  • CDR2 comprising the amino acid sequence shown in SEQ ID NO: 2;
  • CDR2 comprising an amino acid sequence that is at least 80%, 85%, 90%, 95% or 99% identical to SEQ ID NO: 2; or
  • CDR3 comprising the amino acid sequence shown in SEQ ID NO: 3 or 12;
  • CDR3 comprising an amino acid sequence having at least 80%, 85%, 90%, 95% or 99% identity with SEQ ID NO: 3 or 12; or
  • a CDR3 comprising an amino acid sequence with no more than 2 (such as 0, 1, 2) amino acid additions, deletions and/or substitutions compared with SEQ ID NO: 3 or 12.
  • CDR1 represented by the formula RTDSNIX 1 GMH, wherein X 1 is H, F or N;
  • CDR2 represented by the formula TIFIDX 2 NTX 3 , wherein X 2 is G, L or A, and X 3 is I or L;
  • CDR2 comprising SEQ ID NO: 2 or consisting of SEQ ID NO: 2;
  • CDR2 comprising SEQ ID NO: 5 or consisting of SEQ ID NO: 5;
  • CDR2 comprising SEQ ID NO: 7 or consisting of SEQ ID NO: 7;
  • CDR2 comprising SEQ ID NO: 8 or consisting of SEQ ID NO: 8;
  • CDR2 comprising SEQ ID NO: 11 or consisting of SEQ ID NO: 11;
  • CDR2 comprising SEQ ID NO: 5 or consisting of SEQ ID NO: 5;
  • CDR2 comprising SEQ ID NO: 15 or consisting of SEQ ID NO: 15;
  • CDR2 comprising SEQ ID NO: 17 or consisting of SEQ ID NO: 17;
  • CDR2 comprising SEQ ID NO: 19 or consisting of SEQ ID NO: 19;
  • CDR2 comprising SEQ ID NO: 5 or consisting of SEQ ID NO: 5;
  • CDR2 comprising SEQ ID NO: 22 or consisting of SEQ ID NO: 22;
  • CDR2 comprising SEQ ID NO: 25 or consisting of SEQ ID NO: 25;
  • CDR2 comprising SEQ ID NO: 27 or consisting of SEQ ID NO: 27;
  • CDR2 comprising SEQ ID NO: 29 or consisting of SEQ ID NO: 29;
  • CDR2 comprising SEQ ID NO: 31 or consisting of SEQ ID NO: 31;
  • An isolated PD-L1 single domain antibody or antigen-binding fragment thereof which specifically binds to PD-L1 and comprises a heavy chain variable region, wherein the heavy chain variable region comprises SEQ ID NO: 36- There are 3 CDRs in the amino acid sequence of the variable region of the heavy chain shown in any one of 52.
  • the heavy chain variable region further comprises an FR region
  • the FR region comprises FR1, FR2, FR3, and FR4, and CDR1, CDR2, and CDR3 are arranged at intervals on the heavy chain variable region to form a structure of FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4 from N-terminus to C-terminus.
  • FR1 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 53; or
  • An FR1 comprising an amino acid sequence with no more than 2 (such as 0, 1, 2) amino acid additions, deletions and/or substitutions compared with SEQ ID NO: 53;
  • FR2 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 54; or
  • An FR2 comprising an amino acid sequence with no more than 2 (such as 0, 1, 2) amino acid additions, deletions and/or substitutions compared with SEQ ID NO: 54;
  • FR3 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 55; or
  • FR4 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 56; or
  • An FR4 comprising an amino acid sequence with no more than 2 (such as 0, 1, 2) amino acid additions, deletions, and/or substitutions compared with SEQ ID NO: 56.
  • FR1 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 57; or
  • An FR1 comprising an amino acid sequence with no more than 2 (such as 0, 1, 2) amino acid additions, deletions and/or substitutions compared with SEQ ID NO: 57;
  • FR2 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 58; or
  • FR2 comprising an amino acid sequence with no more than 2 (such as 0, 1, 2) amino acid additions, deletions and/or substitutions compared with SEQ ID NO: 58;
  • FR3 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 59; or
  • FR4 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 60; or
  • FR1 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 61; or
  • FR2 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 58; or
  • FR2 comprising an amino acid sequence with no more than 2 (such as 0, 1, 2) amino acid additions, deletions and/or substitutions compared with SEQ ID NO: 58;
  • FR3 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 59; or
  • FR4 comprising an amino acid sequence that is at least 90%, 95% or 99% identical to SEQ ID NO: 60; or
  • the isolated PD-L1 single domain antibody or antigen-binding fragment thereof according to any one of embodiments 1-22, wherein the heavy chain variable region comprises any one of SEQ ID NO: 36-52
  • the amino acid sequence shown may be composed of the amino acid sequence shown in any one of SEQ ID NO: 36-52.
  • the isolated PD-L1 single domain antibody or antigen-binding fragment thereof according to any one of embodiments 1-22, wherein the heavy chain variable region comprises any one of SEQ ID NO: 36-52
  • the amino acid sequence shown in the item has at least 80%, 85%, 90%, 95% or 99% identity and retains the ability to specifically bind to PD-L1.
  • the isolated PD-L1 single domain antibody or antigen-binding fragment thereof according to any one of embodiments 1-22, wherein the heavy chain variable region comprises any one of SEQ ID NO: 36-52
  • the amino acid sequence shown in the item has one or more amino acid additions, deletions and/or substitutions (for example, conservative substitutions) and retains the ability to specifically bind to PD-L1 compared to the amino acid sequence, wherein the one or There are no more than five additions, deletions and/or substitutions (for example, conservative substitutions) of multiple amino acids, preferably no more than three.
  • the isolated PD-L1 single domain antibody or antigen-binding fragment thereof according to any one of embodiments 1-26, wherein the heavy chain variable region is fused to another molecule, and the other molecule is selected from The Fc domain of immunoglobulins (eg, IgG), antibodies, antigen-binding fragments of antibodies, antibody-drug conjugates, antibody-like molecules, antigen-binding fragments of antibody-like molecules, or fluorescent proteins.
  • immunoglobulins eg, IgG
  • An isolated nucleic acid molecule comprising a nucleotide sequence encoding the isolated PD-L1 single domain antibody or antigen-binding fragment thereof according to any one of embodiments 1-28.
  • a vector comprising the nucleic acid molecule of embodiment 29.
  • a host cell comprising the vector of embodiment 30.
  • a pharmaceutical composition comprising an effective amount of the PD-L1 single domain antibody or antigen-binding fragment thereof according to any one of embodiments 1-28 and a pharmaceutically acceptable carrier.
  • a method for preventing or treating a disease associated with PD-L1 in a subject comprising administering to the subject a therapeutically effective amount of any one of embodiments 1-28 A PD-L1 single domain antibody or an antigen-binding fragment thereof or an effective amount of a pharmaceutical composition comprising the PD-L1 single domain antibody or an antigen-binding fragment thereof according to any one of embodiments 1-27 is administered.
  • a method for modulating the immune response of a subject which comprises administering to the subject a therapeutically effective amount of the PD-L1 single domain antibody or antigen binding thereof according to any one of the embodiments 1-28 Fragment or administration of an effective amount of a pharmaceutical composition comprising the PD-L1 single domain antibody or antigen-binding fragment thereof according to any one of embodiments 1-28, so that the immune response in the subject is regulated.
  • the disease associated with PD-L1 is selected from the group consisting of renal cell carcinoma, non-small cell lung cancer, bladder cancer, urothelial carcinoma, and microsatellite unstable solid tumors.
  • biomacromolecule drug is, for example, various monoclonal antibody drugs that attack tumor cells by T cell recognition, such as rituximab, cetuximab, and trastole Benzumab.
  • kits for preventing or treating a disease related to PD-L1 in a subject comprising a container comprising at least one PD-L1 according to any one of embodiments 1-29 Single domain antibodies or antigen-binding fragments thereof.
  • the PD-L1 single domain antibody or antigen-binding fragment thereof according to any one of embodiments 1-29, for use in the prevention or treatment of a disease related to PD-L1 in a subject.
  • the PD-L1 single domain antibody or antigen-binding fragment thereof according to any one of embodiments 1-29, for use in modulating the immune response of a subject.
  • the PD-L1 single domain antibody or antigen-binding fragment thereof according to any one of embodiments 1-29 in the preparation of a pharmaceutical composition for preventing or treating a disease related to PD-L1 in a subject the use of.
  • the disease associated with PD-L1 is selected from the group consisting of renal cell carcinoma, non-small cell lung cancer, bladder cancer, urothelial carcinoma, and microsatellite unstable solid tumors.
  • the present inventors respectively constructed CHO-s cells expressing human PD-L1, monkey PD-L1, and murine PD-L1, and prepared a control antibody from Roche.
  • the specific method is as follows: construct ExpiCHO expression plasmids of Atezolizumab antibody light chain and heavy chain genes by molecular cloning, pass ExpiCHO cells (purchased from Gibco A29127) one day before transfection, and place the constructed plasmids in a 25ml cell culture system 25 ⁇ g (plasmid mixture containing light chain coding gene and heavy chain coding gene with a mass ratio of 2:1) is mixed with transfection reagent and then dropped into 25ml ExpiCHO cell culture, mixed well, and expressed at 37°C for 18-22 hours Then, add the feed medium according to the instructions in the kit. After the feed, the cells are cultured at 32°C.
  • the expressed cell suspension was centrifuged at high speed to take the supernatant, and the supernatant was filtered through a 0.22 ⁇ m filter membrane and purified by the affinity purification method of Protein A/G affinity chromatography column, using 100mM glycinate (pH3 .0)
  • the target protein is eluted, and then neutralized to pH 7.0 with 1M Tris-HCl. After sampling a small amount, it is identified by SDS-PAGE and then packed and frozen in storage.
  • control antibody KN035 for amino acid sequence, see SEQ ID NO: 35 in the sequence table.
  • Recombinant vector plasmids expressing the full-length protein of human PD-L1 (gi number: NP_054862.1), mouse PD-L1 (gi number: NP_068693) and rhesus monkey PD-L1 (gi number: ABO33163.1) were constructed respectively, using The constructed plasmid was introduced into CHO-s cells (purchased from Thermo Fisher) and A375 melanoma cell line (ATCC, CRL-1619) by electroporation. The CHO-s cell line with high expression of PD-L1 protein of the above three species and the A375 cell line with high expression of human PD-L1 (PD-L1-A375) were obtained through screening.
  • the expression vectors containing the full-length protein gene sequences of human PD-L1, mouse PD-L1 and rhesus PD-L1 were synthesized by gene synthesis technology, and then ligated into E. coli, picked out E. coli single clones and sequenced to get the correct Plasmid cloning, plasmid extraction and sequencing again.
  • CD-CHO serum-free medium Gibco, 10743029
  • Use CD-CHO serum-free medium (Gibco, 10743029) to culture and maintain CHO-s cells. Pass the cells to 5 ⁇ 10 6 /mL the day before electroporation, and use the electroporation kit (Invitrogen, Neon TM Kit, MPK10096) the next day And the electroporation instrument (Invitrogen, NeonTM Transfection System, MP922947) respectively introduced the constructed plasmids into CHO-s cells. The electroporated cells were added to 3mL CD-CHO medium and placed in a carbon dioxide incubator at 37°C for 48 hours.
  • the FACS method was used to identify cell lines, and clones with high expression levels were selected for expansion and cryopreservation.
  • the relevant FACS identification methods are as follows:
  • step 4) twice, centrifuge at 300g to remove the supernatant
  • step 8) Repeat step 7) twice, add FACS buffer to the wells, 200 ⁇ L per well, resuspend the cells, and detect by flow cytometry (Beckman, CytoFLEX AOO-1-1102).
  • the PD-L1 high-expressing cell line (PD-L1-A375) of the A375 cell line (PD-L1-A375) was prepared in the same way as the CHO-s cells were transfected by CLP, and used for the construction of animal models of the A375 cell line.
  • NP_054862.1 extracellular domain protein (Yiqiao Shenzhou, 10084-H05H) to immunize 2 alpacas (Nanchang Dajia Technology). Each alpaca is immunized with 500 ⁇ g each time, once every 2 weeks, for a total of 4 immunizations.
  • the alpaca serum is taken for the immune titer test.
  • Immune titer determination is to determine the binding ability of immune serum against recombinant protein PD-L1 (Yiqiao Shenzhou, 10084-H05H) by ELISA method, and determine the immune effect based on the titer of the bound antibody.
  • Serum dilution Dilute the unimmunized negative serum and post-immune serum with PBS on another dilution plate, 200-fold dilution for the first well, and then 3-fold gradient dilution for the subsequent 7 wells.
  • the two columns of NSY004 and NSY005 are the results of the ELISA coloration experiment of the immunized sera of two alpacas after dilution of different multiples, and the negative serum is the result of the ELISA test of the unimmunized alpaca serum.
  • Table 1 it can be seen that the IgG titers of the two alpacas have reached 256,000, and the immune effect is good, which can be used for the next step of the construction of the peripheral blood immune antibody library.
  • PBMC peripheral blood mononuclear cells
  • GE Ficoll-Paque density gradient separation solution
  • the entire liquid surface is divided into four layers, the upper layer is the plasma mixture, the lower layer is red blood cells and granulocytes, the middle layer is Ficoll-Paque PLUS, and at the junction of the upper and middle layers there is a white narrow band dominated by PBMC, that is, the PBMC cell layer .
  • Germline-specific degenerate primers containing NcoI and NotI restriction sites at both ends were designed to amplify all VHH genes using the recovered product as a template
  • the target antibody gene fragment is inserted into the phage display vector by double enzyme digestion and ligation. It should be pointed out that the C-terminus of the VHH gene on the expression vector is fused with the GIII gene in the phage expression vector.
  • the ligation product was recovered by a recovery kit (Omega, D6492-02), and finally transformed into a competent E.
  • coli SS320 by an electroporator (Bio-Rad, MicroPulser), and coated on an ampicillin-resistant 2-YT solid plate.
  • an electroporator Bio-Rad, MicroPulser
  • 10 ⁇ l of the bacterial solution from the library was diluted by 10 times, and 2 ⁇ l of each dilution gradient was spotted on the plate, and the clones formed on the plate were counted to calculate the total number of clones formed by all electrotransformation, that is, the storage capacity.
  • the capacity of this immune library is 1 ⁇ 10 9 .
  • the supernatant was centrifuged at 13000g for 10 minutes, and the supernatant was precipitated by adding 20% PEG/NaCl solution to obtain the phage corresponding to the alpaca immune antibody library. After being washed with PBS once, it was used for the target target PD-L1 antibody screening.
  • Phage screening uses recombinant PD-L1 protein, using two methods: magnetic bead screening and immunotube screening. The specific methods are as follows.
  • Biotin-labeled recombinant PD-L1 protein to avidin-coupled magnetic beads (purchased from Thermo Fisher, catalog number: 11205D).
  • biotin the recombinant human PD-L1 protein (biotin) is labeled with biotin.
  • biotin for the method of labeling, please refer to Roche’s biotin protein labeling kit manual, item number: 11418165001).
  • the SS320 bacteriophage is used to prepare the phage, and the preparation method is detailed in the preparation method of the library phage above.
  • the finally obtained phage continue to be used in the second round of screening, and eluted by trypsin at the end of the second round of screening.
  • the phage obtained in the second round of screening was used in the third round of screening, and trypsin was used for elution at the end of the third round of screening. This is repeated, and sequence analysis is performed on 10 clones randomly selected in each round. The results showed that the monoclonal phage obtained after 3 rounds of screening, the single clone after sequencing, the gene sequence of different clones were duplicated, which proved that the sequence was enriched obviously.
  • Immune tube screening is based on coating the antigen on the surface of the immune tube and screening the antibody display phage that binds to the target antigen.
  • One day before screening use recombinant human PD-L1 protein to coat the immune tube in advance, and incubate the immune tube with PD-L1 antigen and the phage library with Nanobody display for 2 hours at room temperature. After washing 6-8 times with PBST, remove non-special specialties. Heterotropically adsorbed phage, add trypsin (Gibco) and mix gently for 20 minutes to elute the nanobody display phage that specifically binds to human PD-L1 protein.
  • the eluted phages were infected with logarithmic SS320 cells (Lucigen, MC1061 F), and the SS320 cells infected by the phages were spread on a carbenicillin resistant plate, incubated overnight at 37°C, and collected the next day Bacteria.
  • the SS320 bacteriophage is used to prepare the phage, and the preparation method is detailed in the preparation method of the library phage above.
  • the resulting phage will continue to be used in the second round of screening. At the end of the second round of screening, trypsin was used for elution.
  • the phage obtained in the second round of screening was used in the third round of screening, and the Trypsin method was used for elution at the end of the third round of screening. This is repeated, 10 clones selected at random in each round are sequenced and then sequenced. The results showed that after 3 rounds of screening, the single clones after sequencing, the gene sequences of different clones were duplicated, which proved that the sequence enrichment was obvious.
  • Monoclonal screening was performed on the phage library obtained by two different screening methods, and the positive clones in the third round of products of magnetic bead screening and immunotube screening were selected respectively.
  • the specific method is as follows:
  • the recombinant human PD-L1 protein was coated on a 96-well ELISA plate the day before screening, and the induced phage supernatant was prepared in a 96-well plate the next day.
  • the positive clones against the recombinant human PD-L1 protein were screened by phage ELISA, and then selected. Take all the positive clones for sequencing analysis, prepare the lysate for the clone with the unique sequence.
  • the preparation method is as follows: the day before, the clone’s bacterial solution was inoculated with 50mL at a ratio of 1:100, cultured on a constant temperature shaker at 37°C for 14h, centrifuged at 10000g at room temperature for 5min, and used Resuspend the bacteria in 1 mL of pH 9.0 Tris-HCl buffer containing benzonase nuclease, lyse on ice for 30 minutes, centrifuge at 10,000 g at 4°C for 10 minutes, and collect the supernatant to obtain a positive clone lysate.
  • the prepared positive clone lysate was further verified at the flow cytometry level, and candidate antibodies that specifically recognized human PD-L1 were screened.
  • the streaming level verification method is as follows:
  • step 4) twice, centrifuge at 300g to remove the supernatant
  • step 8) Repeat step 7) twice, add FACS buffer to the wells, 200 ⁇ L per well, resuspend the cells, and detect by flow cytometry (Beckman, CytoFLEX AOO-1-1102).
  • the prepared positive clone lysate was further subjected to blocking screening at the flow cytometric level, and candidate antibodies that specifically recognized human PD-L1 and blocked its binding to PD-1 protein were screened.
  • the streaming level verification method is as follows:
  • step 4) twice, centrifuge at 300g to remove the supernatant
  • step 8) Repeat step 7) twice, centrifuge at 300g to remove the supernatant;
  • step 11 Repeat step 10) twice, add FACS buffer to the wells, 200 ⁇ L per well, resuspend the cells, and detect by flow cytometry (Beckman, CytoFLEX AOO-1-1102).
  • the blocking experiment screening results of anti-PD-L1 antibody candidate molecules are shown in Figure 2.
  • Figure 2 Through preliminary screening by ELISA and FACS and other methods, it can be seen that the antibody lysate prepared by the screened antibody sequence contains the binding of PD-L1 to PD1.
  • the inventors In response to antibodies with blocking effects, the inventors screened 10 candidate molecules with good affinity and blocking activity.
  • the positive VHH candidate antibody obtained from the screening was fused with the human IgG1Fc segment, and the C-terminus of the positive VHH gene sequence was connected to the N-terminus of the human IgG1Fc fragment gene sequence to construct a fusion expression vector.
  • the fusion expression vector plasmid was transformed into ExpiCHO cells to induce expression A VHH-Fc chimeric antibody protein fused with an Fc fragment was obtained.
  • the antibody expression uses the ExpiCHO transient expression system, the medium is (Gibco, A29100-01), and the transfection kit is (Gibco, A29129).
  • the specific method is as follows: the day before transfection, the ExpiCHO cells are passaged. In a 25ml system, mix 25 ⁇ g of the constructed plasmid with the transfection reagent and add dropwise to 25ml ExpiCHO cell culture, mix well, and express 18- at 37°C. After 22 hours, add the feed medium according to the instructions in the kit. After the feed, the cells were cultured at 32°C. On the 5th day after transfection, the second feed was added and the cells were cultured at 32°C.
  • VHH-Fc candidate antibody was evaluated, and the FACS method was used to detect its binding activity to the PD-L1 protein on the cell.
  • the specific method is as follows:
  • step 4) twice, centrifuge at 300g to remove the supernatant
  • step 10) twice, add FACS buffer to the wells, 200 ⁇ L per well, resuspend the cells, and detect by flow cytometry (Beckman, CytoFLEX AOO-1-1102).
  • the inventors screened two candidate nanobody molecules (NB22D-21 and NB22gb-10) with high affinity, and the affinity is higher than or similar to that of the control antibody.
  • VHH-Fc candidate antibody was evaluated, and the FACS method was used to detect its blocking activity against PD-1/PD-L1.
  • the specific method is as follows:
  • step 4) twice, centrifuge at 300g to remove the supernatant
  • step 8) Repeat step 7) twice, centrifuge at 300g to remove the supernatant;
  • step 11 Repeat step 10) twice, add FACS buffer to the wells, 200 ⁇ L per well, resuspend the cells, and test by flow cytometer (Beckman, CytoFLEX AOO-1-1102).
  • Example 5 As shown in Table 3, through FACS experiments, the inventors verified that the two candidate Nanobody molecules with clone numbers NB22D-21 and NB22gb-10 in Example 5 have high blocking activities at the same time, and their blocking activities are both higher than
  • the control antibody may be similar to the control antibody.
  • VHH-Fc candidate antibody was evaluated, and the FACS method was used to detect its blocking activity against CD80/PD-L1.
  • the specific method is as follows:
  • step 4) twice, centrifuge at 300g to remove the supernatant
  • step 8) Repeat step 7) twice, centrifuge at 300g to remove the supernatant;
  • step 11 Repeat step 10) twice, add FACS buffer to the wells, 200 ⁇ L per well, resuspend the cells, and detect by flow cytometry (Beckman, CytoFLEX AOO-1-1102).
  • Example 5 As shown in Table 4, through FACS experiments, the inventors verified that the two candidate Nanobody molecules with clone numbers NB22D-21 and NB22gb-10 in Example 5 have high blocking activities at the same time, and their blocking activities are both higher than
  • the control antibody may be similar to the control antibody.
  • step 4) twice, centrifuge at 300g to remove the supernatant
  • step 8) Repeat step 7) twice, centrifuge at 300g to remove the supernatant;
  • step 11 Repeat step 10) twice, add FACS buffer to the wells, 200 ⁇ L per well, resuspend the cells, and test by flow cytometry (Beckman, CytoFLEX AOO-1-1102). The test results are shown in Figure 3.
  • the FACS method was used to detect its binding activity with PD-L1 protein on cells.
  • the specific method is as follows:
  • step 4) twice, centrifuge at 300g to remove the supernatant
  • step 8) Repeat step 7) twice, centrifuge at 300g to remove the supernatant;
  • step 11 Repeat step 10) twice, add FACS buffer to the wells, 200 ⁇ L per well, resuspend the cells, and detect by flow cytometry (Beckman, CytoFLEX AOO-1-1102).
  • the ELISA method was used to detect the activity of the candidate molecule in binding to other proteins of the B7 family.
  • the specific method is as follows:
  • B7-H1 ie, PDL1
  • B7-H2, B7-H3, B7-H4, and B7-DC with a final concentration of 2 ⁇ g/mL
  • the product numbers are 10084-HNAH, 11559-H08H, 11188-H08H, 10738-H08H, 10292-H08H-B) and other protein diluents, incubate overnight at 4°C; rinse the ELISA plate 3 times with PBST on the second day, and then add Block the ELISA plate with 150 ⁇ L 5% PBSM and incubate at room temperature for 2 hours; then wash the plate 3 times with PBST, then add 30 ⁇ L of candidate antibody and control antibody dilutions to the ELISA plate, and incubate at room temperature for 1 hour; wash the plate 3 times with PBST and add
  • N/A Indicates that no binding activity was detected.
  • the inventors established a mixed lymphocyte response system in vitro.
  • the specific method is as follows:
  • the inventors By detecting the secretion of IL-2, the inventors obtained the verification result of the mixed lymphocyte reaction test of the antibody molecule, which is shown in FIG. 5. It can be seen from Figure 5 that the candidate Nanobody molecule of the present invention can activate an immune response.
  • the present inventors carried out a humanized design of the candidate molecule.
  • Use Discovery Studio and Antibody Modeling using homology modeling methods to model, select 5-10 optimal structural solutions, loop regions generally use homology modeling methods to model, if the CDR amino acid sequence alignment results show less than 50% identity, then Use the ab initio modeling method to build the CDR3 structure model.
  • Use PDB BLAST to retrieve the 10 antibody crystal structure models with the closest sequence (the structure resolution is higher than 2.5 angstroms), compare the automatic modeling models, and select the best structure model.
  • the inventors have carried out antibody humanization modification on the NB22D-21 molecule, and obtained two humanized molecules. The numbers of the two humanized modified molecules are NB22D-21-huVH1 and NB22D-21-huVH2, respectively.
  • Example 13 Humanized modified derivative molecules bind to human PD-L1-CHO cells
  • the inventors used FACS to detect candidate molecules and their humanized derivatives.
  • step 4) twice, centrifuge at 300g to remove the supernatant
  • step 8) Repeat step 7) twice, add FACS buffer to the wells, 200 ⁇ L per well, resuspend the cells, and detect by flow cytometry (Beckman, CytoFLEX AOO-1-1102), and the results are shown in Figure 6.
  • Example 14 Humanized modified derivative molecules bind to mouse PD-L1-CHO cells
  • the inventors used FACS to test the candidate molecule.
  • step 4) twice, centrifuge at 300g to remove the supernatant
  • step 8) Repeat step 7) twice, add FACS buffer to the wells, 200 ⁇ L per well, resuspend the cells, and detect by flow cytometry (Beckman, CytoFLEXAOO-1-1102). The results are shown in Figure 7 and Figure 8.
  • NB22D-21-huVH1 binds to mouse PD-L1 with better affinity than the parent molecule (ie, NB22D-21).
  • the derived molecules obtained after humanization were evaluated, and the FACS method was used to detect the blocking activity of PD-1/PD-L1.
  • the specific methods are as follows:
  • step 4) twice, centrifuge at 300g to remove the supernatant
  • step 8) Repeat step 7) twice, centrifuge at 300g to remove the supernatant;
  • step 11 Repeat step 10) twice, add FACS buffer to the wells, 200 ⁇ L per well, resuspend the cells, and detect by flow cytometry (Beckman, CytoFLEX AOO-1-1102), and the results are shown in Figure 9.
  • the present inventors carried out affinity maturation design on antibody-derived molecules obtained after humanization transformation.
  • Affinity maturation adopts methods such as single-point saturation mutation, multi-point combined mutation, and chain replacement.
  • Trim primer technology is used to design primers for the CDR region to construct affinity maturation antibody library
  • phage display technology is used to screen the molecules after affinity maturation.
  • a VHH lysate was prepared, and FACS was used to detect the affinity and blocking activity of the clone.
  • FACS was used to detect the affinity and blocking activity of the clone.
  • 4 clones that may be superior to the female parent namely SY01-201, SY01-208, SY01-NB-004 and SY01-NB-027-M.
  • the present inventors designed the druggability modification of the antibody-derived molecule NB22D-21-huVH2 obtained after humanization.
  • Drug-ready modification uses point mutations to randomly mutate potential post-translational modification sites to construct a drug-ready-modified antibody library, and use phage display technology to screen the molecules after drug-ready modification. After obtaining a single clone, a VHH lysate was prepared, and FACS was used to detect the blocking activity of the clone on PD-L1-CHO.
  • the present inventors obtained 10 modified molecules with drug-like properties: SY01-D21-3, SY01-D21-4, SY01-D21-5, SY01-D21-6, SY01-D21-8, SY01 -D21-17, SY01-D21-21, SY01-D21-24, SY01-D21-38 and SY01-D21-47 (abbreviated as 3, 4, 5, 6, 8, 17, 21, 24, 38 and 47, the parent molecule is NB22D-21-huVH2, abbreviated as D21-Vh2, and the isotype control (isotype) is human IgG1).
  • the inventors have obtained 5 possible better than the parent
  • the clones are SY01-D21-4, SY01-D21-8, SY01-D21-17, SY01-D21-24 and SY01-D21-47.
  • the positive VHH candidate antibodies SY01-D21-4, SY01-D21-8, SY01-D21-17 and SY01-D21-24 obtained from the screening were fused with the human IgG1Fc fragment, and the C-terminus of the positive VHH gene sequence was connected to the human IgG1Fc fragment
  • the fusion expression vector was constructed by using the N-terminus of the gene sequence, and the fusion expression vector plasmid was transformed into ExpiCHO cells, and the expression of 4 kinds of VHH-Fc chimeric antibody proteins fused with Fc fragments were obtained, respectively, called NB22D-21-4 and NB22D- 21-8, NB22D-21-17 and NB22D-21-24.
  • the antibody expression uses the ExpiCHO transient expression system, the medium is (Gibco, A29100-01), and the transfection kit is (Gibco, A29129).
  • the specific method is as follows: the day before transfection, the ExpiCHO cells are passaged. In a 25ml system, mix 25 ⁇ g of the constructed plasmid with the transfection reagent and add dropwise to 25ml ExpiCHO cell culture, mix well, and express 18- at 37°C. After 22 hours, add the feed medium according to the instructions in the kit. After the feed, the cells were cultured at 32°C. On the 5th day after transfection, the second feed was added and the cells were cultured at 32°C.
  • VHH-Fc candidate antibodies obtained after drug-ready modification were evaluated, and the FACS method was used to detect their binding activity to human and monkey PD-L1 proteins on the cells.
  • the specific methods are as follows:
  • step 4) twice, centrifuge at 300g to remove the supernatant
  • step 10) twice, add FACS buffer to the wells, 200 ⁇ L per well, resuspend the cells, and detect by flow cytometry (Beckman, CytoFLEX AOO-1-1102).
  • VHH-Fc candidate antibody was evaluated, and the FACS method was used to detect its blocking activity against PD-1/PD-L1.
  • the specific method is as follows:
  • step 4) twice, centrifuge at 300g to remove the supernatant
  • step 8) Repeat step 7) twice, centrifuge at 300g to remove the supernatant;
  • step 11 Repeat step 10) twice, add FACS buffer to the wells, 200 ⁇ L per well, resuspend the cells, and test by flow cytometer (Beckman, CytoFLEX AOO-1-1102).
  • Example 19 As shown in Table 8, through FACS experiments, the inventors verified that the two candidate Nanobody molecules with clone numbers NB22D-21-4 and NB22D-21-24 in Example 19 have high blocking activity at the same time, which blocks The activity is higher than that of NB22D-21-huVH2 antibody.
  • the FACS method is used to detect the specificity of the candidate molecule binding to the cell, which is divided into two parts.
  • the specific method of the first part is as follows:
  • step 4) four times, centrifuge at 300g to remove the supernatant;
  • step 10) twice, add FACS buffer to the wells, 200 ⁇ L per well, resuspend the cells, and detect by flow cytometry (Beckman, CytoFLEX AOO-1-1102).
  • the inventors used the FACS method to detect the specificity of the NB22D-21-4 clone binding to B7 family proteins.
  • the specific method is as follows:
  • step 4) four times, centrifuge at 300g to remove the supernatant;
  • step 10) twice, add FACS buffer to the wells, 200 ⁇ L per well, resuspend the cells, and detect by flow cytometry (Beckman, CytoFLEX AOO-1-1102).
  • the inventors established a mixed lymphocyte reaction system in vitro.
  • the specific method is as follows:
  • the present inventors By detecting the secretion of IFN- ⁇ and IL-2, the present inventors obtained the mixed lymphocyte reaction test verification result of the antibody molecule, which is shown in FIG. 16. It can be seen from Fig. 16 that the candidate Nanobody molecule NB22D-21-4 of the present invention can activate the immune response.
  • This round of affinity maturation adopts the single-point saturation mutation method, and uses Trim primer technology to design primers for the CDR region to construct an affinity maturation antibody library, and continue to use phage display technology to screen the affinity matured molecules.
  • the mouse antigens were used to conduct sea selection and preliminary screening of affinity maturation libraries, and the monoclonal antibodies were obtained to construct and express full-length antibodies.
  • FACS was used to detect the affinity, human-mouse crossover and blocking activities of candidate clones. Through screening, we obtained 5 clones with better activity than the original parent, namely NB22D-21-45-106, NB22D-21-123, NB22D-21-154, NB22D-21-94 and NB22D-21-109.

Landscapes

  • Health & Medical Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Immunology (AREA)
  • Organic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Genetics & Genomics (AREA)
  • General Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Biochemistry (AREA)
  • Biophysics (AREA)
  • Molecular Biology (AREA)
  • Engineering & Computer Science (AREA)
  • Veterinary Medicine (AREA)
  • Public Health (AREA)
  • Proteomics, Peptides & Aminoacids (AREA)
  • Animal Behavior & Ethology (AREA)
  • Pharmacology & Pharmacy (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • General Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Biomedical Technology (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Wood Science & Technology (AREA)
  • Zoology (AREA)
  • General Engineering & Computer Science (AREA)
  • Biotechnology (AREA)
  • Plant Pathology (AREA)
  • Microbiology (AREA)
  • Physics & Mathematics (AREA)
  • Peptides Or Proteins (AREA)
  • Medicines Containing Antibodies Or Antigens For Use As Internal Diagnostic Agents (AREA)
  • Preparation Of Compounds By Using Micro-Organisms (AREA)
  • Micro-Organisms Or Cultivation Processes Thereof (AREA)

Abstract

本申请提供了一种分离的PD-L1结合分子，具体为一种分离的PD-L1单结构域抗体或其抗原结合片段。本发明还提供编码该分离的PD-L1结合分子的核酸以及包含该核酸的表达载体或宿主细胞、以及包含该PD-L1结合分子的药物组合物或试剂盒。

Description

PD-L1结合分子
优先权信息
本申请要求于2019年10月30日提交的中国发明专利申请号201911044297.0和于2020年7月31日提交的中国发明专利申请号202010765530.0的权益，上述申请的内容通过引用完全结合在本文中。
技术领域
本申请属于生物技术领域，一般而言涉及抗体。更具体地，本申请涉及特异性识别PD-L1的结合分子(例如，单结构域抗体)、其制备方法及其用途。
背景技术
免疫检查点是免疫系统中起到抑制作用的调控分子，包括CTLA-4、PD-1、LAG-3、TIM-3等，目前基于CTLA-4和PD-1这两个免疫检查点已经有多个抗体药物上市。PD-1(programmed death 1，程序性死亡受体1)，是一种重要的免疫抑制分子，其最初是从凋亡的小鼠T细胞杂交瘤2B4.11克隆出来。以PD-1为靶点的免疫调节对抗肿瘤、抗感染、抗自身免疫性疾病及器官移植存活等均有重要的意义。
PD-1的主要配体为PD-L1和PD-L2，其中PD-L1在介导肿瘤细胞逃逸过程中扮演着重要作用，其高表达于肿瘤细胞和一些抗原递呈细胞，且表达量可以被多种细胞因子如IFN-γ、TGF-β等诱导。在肿瘤微环境中，PD-L1的表达上调通过PD-1信号通路可直接抑制T细胞的抗肿瘤反应，介导肿瘤细胞的免疫逃逸。
单结构域抗体简称单域抗体(single domain antibody，sdAb)，是包含单个抗体重链可变区结构域的抗体。类似IgG抗体，它能够选择性结合特定的抗原，但单域抗体的分子量却远小于IgG抗体。目前第一个单域抗体是由骆驼科动物中发现的重链抗体改造而来的(Hamers-Casterman C，Atarhouch T，Muyldermans S，Robinson G，Hamers C，Songa EB，Bendahman N，Hamers R(1993)Naturally occurring antibodies devoid of light chains.Nature 363(6428)：446-448.)；这些骆驼科动物中发现的重链抗体也被称为VHH片段。目前，对单域抗体的大多数研究基于重链可变结构域。
单域抗体具有许多优点。例如，它们具有较高的溶解度、良好的热稳定性和组织渗 透性，有些单域抗体由于分子内二硫键的存在还可耐受木瓜蛋白酶等的降解作用；此外单域抗体可以在酵母、植物和哺乳动物细胞等多种表达宿主中产生，且表达量较高，使得其具有极高的成本效益。(Harmsen MM，De Haard HJ(2007)Properties，production，and applications of camelid single-domain antibody fragments.Appl Microbiol Biotechnol 77(1)：13-22.)。单域抗体凭借其众多的优点，使其在各种生物技术和医疗领域具有良好的应用前景。目前Ablynx公司的第一个单域抗体药物已经获批上市。
目前针对PD-L1靶点的上市抗体药物还不多，因此，仍然需要研发新的特异性识别PD-L1的结合分子(例如，单结构域抗体)用于癌症的免疫治疗，使其具有更低的毒副作用和更佳的临床药效。
发明内容
本发明的目的是提供一种新的PD-L1结合分子，具体而言，提供一种新的特异性识别PD-L1的单结构域抗体。与现有的PD-L1结合分子相比，本发明的PD-L1结合分子具有更低的毒副作用和更佳的临床药效，能够更有效地治疗癌症。
总的来说，本发明提供一种特异性识别PD-L1的结合分子，具体为特异性识别PD-L1的单结构域抗体。所述单结构域抗体在下文中也称为PD-L1单结构域抗体、纳米抗体形式的PD-L1抗体、PD-L1纳米抗体或PD-L1的VHH抗体，以上术语可以互换使用。本申请还提供了构建和筛选所述PD-L1结合分子的方法，编码所述PD-L1结合分子的核酸分子、用于表达PD-L1结合分子的载体和宿主细胞以及包含所述PD-L1结合分子的组合物或试剂盒。本申请的PD-L1结合分子能够通过调节免疫系统治疗多种癌症，因此能够用于制备治疗癌症的药剂。
具体而言，本发明提供纳米抗体形式的PD-L1抗体以及其人源化改造或亲和力成熟后的衍生分子，在保持高亲和力、低分子量等优势的同时，进行免疫原性修饰，改善了成药性，具有极大的治疗优势。
在一些方面，本发明提供分离的PD-L1结合分子，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
(i)包含SEQ ID NO：1所示氨基酸序列的CDR1；
包含与SEQ ID NO：1具有至少80％、85％、90％、95％或99％同一性的氨基酸序列的CDR1；或
包含与SEQ ID NO：1相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的CDR1；
(ii)包含SEQ ID NO：2所示氨基酸序列的CDR2；
包含与SEQ ID NO：2具有至少80％、85％、90％、95％或99％同一性的氨基酸序列的CDR2；或
包含与SEQ ID NO：2相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的CDR2；
和
(iii)包含SEQ ID NO：3或12所示氨基酸序列的CDR3；
包含与SEQ ID NO：3或12具有至少80％、85％、90％、95％或99％同一性的氨基酸序列的CDR3；或
包含与SEQ ID NO：3或12相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的CDR3。
在一些实施方案中，所述PD-L1结合分子包含重链可变区，所述重链可变区包含：
(i)如式RTDSNIX 1GMH所示的CDR1，其中X 1为H、F或N；
(ii)如式TIFIDX 2NTX 3所示的CDR2，其中X 2为G、L或A，X 3为I或L；和
(iii)如式DVSGYGRX 4所示的CDR3，其中X 4为A或Y。
在一些实施方案中，所述PD-L1结合分子包含重链可变区，所述重链可变区包含：
(i)包含SEQ ID NO：1或由SEQ ID NO：1组成的CDR1；
(ii)包含SEQ ID NO：2或由SEQ ID NO：2组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
在一些实施方案中，所述PD-L1结合分子包含重链可变区，所述重链可变区包含：
(i)包含SEQ ID NO：4或由SEQ ID NO：4组成的CDR1；
(ii)包含SEQ ID NO：5或由SEQ ID NO：5组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
在一些实施方案中，所述PD-L1结合分子包含重链可变区，所述重链可变区包含：
(i)包含SEQ ID NO：6或由SEQ ID NO：6组成的CDR1；
(ii)包含SEQ ID NO：7或由SEQ ID NO：7组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
在一些实施方案中，所述PD-L1结合分子包含重链可变区，所述重链可变区包含：
(i)包含SEQ ID NO：1或由SEQ ID NO：1组成的CDR1；
(ii)包含SEQ ID NO：8或由SEQ ID NO：8组成的CDR2；和
(iii)包含SEQ ID NO：9或由SEQ ID NO：9组成的CDR3。
在一些实施方案中，所述PD-L1结合分子包含重链可变区，所述重链可变区包含：
(i)包含SEQ ID NO：10或由SEQ ID NO：10组成的CDR1；
(ii)包含SEQ ID NO：11或由SEQ ID NO：11组成的CDR2；和
(iii)包含SEQ ID NO：12或由SEQ ID NO：12组成的CDR3。
在一些实施方案中，所述PD-L1结合分子包含重链可变区，所述重链可变区包含：
(i)包含SEQ ID NO：13或由SEQ ID NO：13组成的CDR1；
(ii)包含SEQ ID NO：5或由SEQ ID NO：5组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
在一些实施方案中，所述PD-L1结合分子包含重链可变区，所述重链可变区包含：
(i)包含SEQ ID NO：14或由SEQ ID NO：14组成的CDR1；
(ii)包含SEQ ID NO：15或由SEQ ID NO：15组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
在一些实施方案中，所述PD-L1结合分子包含重链可变区，所述重链可变区包含：
(i)包含SEQ ID NO：16或由SEQ ID NO：16组成的CDR1；
(ii)包含SEQ ID NO：17或由SEQ ID NO：17组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
在一些实施方案中，所述PD-L1结合分子包含重链可变区，所述重链可变区包含：
(i)包含SEQ ID NO：18或由SEQ ID NO：18组成的CDR1；
(ii)包含SEQ ID NO：19或由SEQ ID NO：19组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
在一些实施方案中，所述PD-L1结合分子包含重链可变区，所述重链可变区包含：
(i)包含SEQ ID NO：20或由SEQ ID NO：20组成的CDR1；
(ii)包含SEQ ID NO：5或由SEQ ID NO：5组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
在一些方面，本发明提供一种分离的PD-L1结合分子，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
(i)包含SEQ ID NO：21或由SEQ ID NO：21组成的CDR1；
(ii)包含SEQ ID NO：22或由SEQ ID NO：22组成的CDR2；和
(iii)包含SEQ ID NO：23或由SEQ ID NO：23组成的CDR3。
在一些方面，本发明提供一种分离的PD-L1结合分子，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
(i)包含SEQ ID NO：24或由SEQ ID NO：24组成的CDR1；
(ii)包含SEQ ID NO：25或由SEQ ID NO：25组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
在一些方面，本发明提供一种分离的PD-L1结合分子，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
(i)包含SEQ ID NO：26或由SEQ ID NO：26组成的CDR1；
(ii)包含SEQ ID NO：27或由SEQ ID NO：27组成的CDR2；和
(iii)包含SEQ ID NO：23或由SEQ ID NO：23组成的CDR3。
在一些方面，本发明提供一种分离的PD-L1结合分子，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
(i)包含SEQ ID NO：28或由SEQ ID NO：28组成的CDR1；
(ii)包含SEQ ID NO：29或由SEQ ID NO：29组成的CDR2；和
(iii)包含SEQ ID NO：23或由SEQ ID NO：23组成的CDR3。
在一些方面，本发明提供一种分离的PD-L1结合分子，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
(i)包含SEQ ID NO：30或由SEQ ID NO：30组成的CDR1；
(ii)包含SEQ ID NO：31或由SEQ ID NO：31组成的CDR2；和
(iii)包含SEQ ID NO：23或由SEQ ID NO：23组成的CDR3。
在一些方面，本发明提供一种分离的PD-L1结合分子，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含SEQ ID NO：36-52中任一条所示的重链可变区氨基酸序列中的3个CDR。
在一些实施方案中，在本发明所述的分离的PD-L1结合分子中，所述重链可变区还包含FR区，所述FR区包含FR1、FR2、FR3和FR4，并且与CDR1、CDR2和CDR3在所述重链可变区上间隔排列形成从N端到C端为FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4的结构。
在优选的实施方案中，在本发明所述的分离的PD-L1结合分子中，所述FR区包含：
(a)包含SEQ ID NO：53所示氨基酸序列的FR1；
包含与SEQ ID NO：53具有至少90％、95％或99％同一性的氨基酸序列的FR1；或
包含与SEQ ID NO：53相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR1；
(b)包含SEQ ID NO：54所示氨基酸序列的FR2；
包含与SEQ ID NO：54具有至少90％、95％或99％同一性的氨基酸序列的FR2；或
包含与SEQ ID NO：54相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR2；
(c)包含SEQ ID NO：55所示氨基酸序列的FR3；
包含与SEQ ID NO：55具有至少90％、95％或99％同一性的氨基酸序列的FR3；或
包含与SEQ ID NO：55相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR3；
和
(d)包含SEQ ID NO：56所示氨基酸序列的FR4；
包含与SEQ ID NO：56具有至少90％、95％或99％同一性的氨基酸序列的FR4；或
包含与SEQ ID NO：56相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR4。
在优选的实施方案中，在本发明所述的分离的PD-L1结合分子中，所述FR区包含：
(a)包含SEQ ID NO：57所示氨基酸序列的FR1；
包含与SEQ ID NO：57具有至少90％、95％或99％同一性的氨基酸序列的FR1；或
包含与SEQ ID NO：57相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR1；
(b)包含SEQ ID NO：58所示氨基酸序列的FR2；
包含与SEQ ID NO：58具有至少90％、95％或99％同一性的氨基酸序列的FR2；或
包含与SEQ ID NO：58相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR2；
(c)包含SEQ ID NO：59所示氨基酸序列的FR3；
包含与SEQ ID NO：59具有至少90％、95％或99％同一性的氨基酸序列的FR3；或
包含与SEQ ID NO：59相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR3；
和
(d)包含SEQ ID NO：60所示氨基酸序列的FR4；
包含与SEQ ID NO：60具有至少90％、95％或99％同一性的氨基酸序列的FR4；或
包含与SEQ ID NO：60相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR4。
在优选的实施方案中，在本发明所述的分离的PD-L1结合分子中，所述FR区包含：
(a)包含SEQ ID NO：61所示氨基酸序列的FR1；
包含与SEQ ID NO：61具有至少90％、95％或99％同一性的氨基酸序列的FR1；或
包含与SEQ ID NO：61相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR1；
(b)包含SEQ ID NO：58所示氨基酸序列的FR2；
包含与SEQ ID NO：58具有至少90％、95％或99％同一性的氨基酸序列的FR2；或
包含与SEQ ID NO：58相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR2；
(c)包含SEQ ID NO：59所示氨基酸序列的FR3；
包含与SEQ ID NO：59具有至少90％、95％或99％同一性的氨基酸序列的FR3；或
包含与SEQ ID NO：59相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR3；
和
(d)包含SEQ ID NO：60所示氨基酸序列的FR4；
包含与SEQ ID NO：60具有至少90％、95％或99％同一性的氨基酸序列的FR4；或
包含与SEQ ID NO：60相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR4。
在一些实施方案中，在本发明所述的分离的PD-L1结合分子中，所述重链可变区包含SEQ ID NO：36-52中任一项所示的氨基酸序列或由SEQ ID NO：36-52中任一项所示的氨基酸序列组成。
在一些实施方案中，在本发明所述的分离的PD-L1结合分子中，所述重链可变区包含与SEQ ID NO：36-52中任一项所示的氨基酸序列具有至少80％、85％、90％、95％或99％同一性并且保留特异性结合PD-L1的能力的氨基酸序列。
在一些实施方案中，在本发明所述的分离的PD-L1结合分子中，所述重链可变区包 含与SEQ ID NO：36-52中任一项所示的氨基酸序列相比具有一处或多处氨基酸的添加、缺失和/或取代(例如，保守性取代)并且保留特异性结合PD-L1的能力的氨基酸序列。
在优选的实施方案中，所述一处或多处氨基酸的添加、缺失和/或取代(例如，保守性取代)不超过五处，优选地不超过三处。
在一些方面，本发明所述的分离的PD-L1结合分子为骆驼源抗体、人源化抗体、亲和力成熟的抗体或成药性改造后分子。
在一些方面，本发明所述的分离的PD-L1结合分子为单结构域抗体或其抗原结合片段。因此，本发明还提供分离的纳米抗体形式的PD-L1单结构域抗体。
在一些方面中，本发明所述的分离的PD-L1结合分子的重链可变区可以与另一分子融合，所述另一分子选自免疫球蛋白(例如IgG)的Fc结构域、抗体、抗体的抗原结合片段、抗体-药物偶联物、抗体样分子、抗体样分子的抗原结合片段或荧光蛋白。
在一些实施方案中，所述PD-L1结合分子与人IgG(如人IgG1或人IgG4)的Fc结构域融合。
在一些方面，本发明提供一种分离的核酸分子，其包含编码本发明所述的分离的PD-L1结合分子的核苷酸序列。
在一些方面，本发明提供一种载体，所述载体包含含有编码本发明所述的分离的PD-L1结合分子的核苷酸序列的核酸分子。
在一些方面，本发明提供一种宿主细胞，所述宿主细胞包含含有编码本发明所述的分离的PD-L1结合分子的核苷酸序列的核酸分子或包含本发明所述的载体。
在一些方面，本发明提供一种药物组合物，所述药物组合物包含本发明所述的PD-L1结合分子以及药学上可接受的载体。
在一些实施方案中，所述药物组合物包含本发明所述的PD-L1单结构域抗体或其抗原结合片段以及药学上可接受的载体。
在一些方面，本发明提供制备本发明所述的PD-L1结合分子的方法，所述方法包括以下步骤：
(1)在适当的宿主细胞中使编码本发明所述的分离的PD-L1结合分子的核苷酸序列表达，以产生所述PD-L1结合分子；
(2)从所述宿主细胞分离所述PD-L1结合分子。
在一些方面，本发明涉及调节受试者的免疫应答的方法，其包括向受试者施用如本文所公开的PD-L1结合分子，使得受试者中的免疫应答受到调节。
在一些实施方案中，所述受试者为患有与PD-L1相关的疾病的人或哺乳动物。具体地，所述受试者可能患有下述疾病，但不限于此：肾细胞癌、非小细胞肺癌、膀胱癌、尿路上皮癌、微卫星不稳定型实体瘤等。
在一些方面，本发明涉及用于治疗或预防与PD-L1相关的疾病的方法，其中包括向患有所述与PD-L1相关的疾病的患者或有患有所述与PD-L1相关的疾病的倾向的受试者施用有效量的如本文所公开的PD-L1结合分子、或施用如本文所公开的PD-L1单结构域抗体或其抗原结合片段、或施用有效量的包含如本文所公开的PD-L1结合分子的药物组合物、或施用有效量的包含如本文所公开的PD-L1单结构域抗体或其抗原结合片段的药物组合物。
在一些方面，本发明涉及治疗可以通过消除、抑制或降低PD-L1活性而被改善、减缓、抑制或预防的任何疾病或病症的方法。
在另一些方面，本发明的方法还涉及通过联合疗法治疗或预防肿瘤的方法，所述方法包括向受试者施用有效量的本文所述的PD-L1结合分子、PD-L1单结构域抗体或其抗原结合片段和一种或多种其它药物。
在一些实施方案中，本文公开的方法还包括向受试者联合施用有效量的第二药物，其中本文公开的PD-L1结合分子或PD-L1单结构域抗体或其抗原结合片段是第一药物。在一个实施方案中，第二药物是用于治疗与PD-L1相关的疾病的化疗剂、放疗剂或者生物大分子药物。在一个实施方案中，该生物大分子药物例如是通过T细胞识别攻击肿瘤细胞的各种单克隆抗体药，例如利妥昔单抗、西妥昔单抗与曲妥珠单抗。如本文所用的表述“第二药物”并不意味着它是指第一药物之外的唯一药物。因此，第二药物不必是一种药物，而可以是构成或包含多于一种这类药物。
在一些实施方案中，受试者、患者或个体是哺乳动物，例如，小鼠或人，优选地是人。
在一些方面，本发明涉及如本文所公开的PD-L1结合分子在制备用于治疗或预防与PD-L1相关的疾病的药物中的用途。
在一些方面，本发明涉及如本文所公开的PD-L1单结构域抗体或其抗原结合片段在制备用于治疗或预防与PD-L1相关的疾病的药物中的用途。
在一些实施方案中，所述与PD-L1相关的疾病选自，但不限于肾细胞癌、非小细 胞肺癌、膀胱癌、尿路上皮癌、微卫星不稳定型实体瘤等。
在一些方面，本发明涉及使用如本文所公开的PD-L1结合分子、PD-L1单结构域抗体或其抗原结合片段的试剂盒或装置和相关方法，以及如本文所公开的药物组合物，其可用于治疗与PD-L1相关的疾病，例如，癌症。为此，本发明优选提供可用于治疗此类病症的制品，其包含含有如本文所公开的PD-L1结合分子、PD-L1单结构域抗体或其抗原结合片段的容器以及用于使用如本文所公开的PD-L1单结构域抗体或其抗原结合片段来治疗、改善或预防与PD-L1相关的疾病或其进展或复发的说明材料。
本发明还涵盖本文所述的任何实施方案的任意组合。本文所述的任何实施方案或其任何组合适用于本文所述的发明的任何和所有PD-L1结合分子、PD-L1单结构域抗体或其抗原结合片段、方法和用途。
附图说明
图1显示结合PD-L1的VHH抗体裂解液样本结合亲和力筛选的结果。
图2显示抗PD-L1候选抗体分子的封闭实验筛选的结果。
图3显示候选抗体分子细胞结合实验验证的结果：(A)同种型对照，(B)NB22D-21，(C)NB22gb-10，(D)阳性对照KN035。
图4显示NB22D-21分子的特异性结合反应实验验证结果。
图5显示NB22D-21分子的混合淋巴细胞反应实验验证结果。
图6显示NB22D-21分子及其经人源化改造后的衍生分子的结合实验验证结果。
图7显示NB22D-21分子及其经人源化改造后的衍生分子的人鼠交叉反应实验结果。
图8显示人源化改造后的衍生分子NB22D-21-huVH1的人鼠交叉反应实验的流式峰图结果：(A)对照分子KN035，(B)NB22D-21-huVH1。
图9显示NB22D-21分子及其人源化改造分子的结合封闭实验结果。
图10显示亲和力成熟后的分子在PD-L1-CHO上的亲和力检测结果。
图11显示亲和力成熟后的分子阻断PD-1结合PD-L1-CHO细胞。
图12显示第二次亲和力成熟分子结合人PD-L1-CHO细胞的亲和力检测。
图13显示第二次亲和力成熟分子阻断PD-1结合人PD-L1-CHO细胞的活性检测。
图14显示第二次亲和力成熟分子结合鼠PD-L1细胞的活性检测。
图15显示显示成药性改造后的分子在PD-L1-CHO上的阻断活性，其中同种型对照(isotype)为人IgG1。
图16显示成药性改造后的分子在混合淋巴细胞反应中对IFN-γ(A)和IL-2(B)分泌的影响。
图17显示候选抗体分子的序列比对，其中用方框框出CDR序列。
序列表概述
本申请附带有包含许多核苷酸和氨基酸序列的序列表。下表A、B和C提供了所包含的序列的概述。
Figure PCTCN2020125301-appb-000001
Figure PCTCN2020125301-appb-000002
Figure PCTCN2020125301-appb-000003
Figure PCTCN2020125301-appb-000004
Figure PCTCN2020125301-appb-000005
Figure PCTCN2020125301-appb-000006
具体实施方式
本领域技术人员应该理解，本发明不限于本文中描述的特定方法学、实施方案和试剂，因为这些是示例性说明。还应理解本文中使用的术语仅为了描述具体实施方案，而并不意图限制本发明的范围，本发明的范围仅由所附权利要求书限定。
除非另外定义，本文中使用的所有技术和科学术语与本发明所属领域中普通技术人员通常的理解具有相同的含义。
此外，除非上下文另有要求，单数形式的术语应包括复数形式，复数形式的术语应包括单数形式。更具体地，如在本说明书和所附权利要求中所使用的，除非上下文另外明确指出，否则单数形式“一种”和“这种”包括复数指示物。因此，例如，提及“一种抗体”包括多种抗体。
I.定义
为了更好地理解本发明，相关术语的定义和解释提供如下。
术语“约”在与数字数值联合使用时意为涵盖具有比指定数字数值小5％的下限和比指定数字数值大5％的上限的范围内的数字数值。
术语“抗体”在本文中以最广意义使用并且涵盖多种抗体结构物，包括但不限于单克隆抗体、多克隆抗体、多特异性抗体(例如，双特异性抗体)和抗体片段，只要它们显示出所需的抗原结合活性即可。完整抗体通常将包含至少两条全长重链和两条全长轻链，但在某些情况下可包括较少的链，例如骆驼科动物中天然存在的抗体可仅包含重链。
如本文所用的术语“抗原结合部分”指与靶抗原特异性结合的部分。该术语包括能够与靶抗原特异性结合的抗体以及其他天然分子(例如受体，配体)或合成分子(例如，DARPin)。在一个优选的实施方案中，本发明抗体的抗原结合部分是抗体片段。
术语“全长抗体”、“完好抗体”和“完整抗体”在本文中可互换地用来指一种抗体，所述抗体具有基本上与天然抗体结构相似的结构或具有含有Fc区的重链。
如本文所用，术语“单克隆抗体”或“单克隆抗体组合物”指具有单一氨基酸组成的抗体分子的制备物，而不指其产生的方法。单克隆抗体或其抗原结合片段可以例如通过杂交瘤技术、重组技术、噬菌体展示技术、合成技术例如CDR嫁接、或此类或其它本领域已知的技术的组合来产生。
如本文所用，术语“PD-1”是指程序性细胞死亡蛋白，其属于免疫球蛋白超家族并且作为共抑制性受体发挥作用以负调节免疫系统。PD-1是CD28/CTLA-4家族的成员，并且具有两种已知的配体，包括PD-L1和PD-L2。PD-1的替代名称或同义词包括 PDCD1，PD1，CD279和SLEB2等。在NCBI登录号：NP_005009.2下公开了人PD-1的代表性氨基酸序列，并且在NCBI登录号NM_005018.3下显示了编码人PD-1的代表性核酸序列。
如本文所用，术语“PD-LI”是指程序性细胞死亡配体1(PD-L1，参见例如Freeman等人.(2000)J.Exp.Med.192：1027)。PD-L1的替代名称或同义词包括PDCD1L1，PDL1，B7H1，CD274和B7-H等。人PD-L1的代表性氨基酸序列在NCBI登录号NP_054862.1中公开，编码人PD-L1的代表性核酸序列显示在NCBI登录号：NM_014143.4下。PD-L1在胎盘，脾脏，淋巴结，胸腺，心脏，胎儿肝脏中表达，并且也在许多肿瘤或癌细胞中发现。PD-L1结合其受体PD-1或B7-1，其在活化的T细胞、B细胞和骨髓细胞上表达。PD-L1和其受体的结合诱导信号转导以抑制TCR介导的细胞因子产生和T细胞增殖的激活。因此，PD-L1在特定事件(例如妊娠，自身免疫疾病，组织同种异体移植物)期间抑制免疫系统中起主要作用，并且被认为允许肿瘤或癌细胞绕过免疫检查点并逃避免疫应答。
如本文所用，术语“结合”和“特异性结合”指抗体或抗原结合部分在体外测定法中，优选地在采用纯化的野生型抗原的生物光干涉测量(ForteBio)中与抗原表位结合。在某些实施方案中，在抗体或抗原结合部分优选地识别蛋白质和/或大分子的复杂混合物中其靶抗原时，将抗体或抗原结合部分称作特异性结合抗原。
取决于其重链恒定区的氨基酸序列，将抗体以“类”划分：IgA、IgD、IgE、IgG和IgM，并且这些类别中的几种可以进一步划分成亚类，如，IgG1、IgG2、IgG3和IgG4、IgA1以及IgA2。对应于不同抗体类的重链恒定区分别称作[image]δ、ε、γ和μ。可以在全部五个抗体类中找到的轻链恒定区(CL)称作κ和λ。在全长轻链和重链内，通常可变区和恒定区由约12个或更多个氨基酸的“J”区连接，且重链还包括约10个以上氨基酸的“D”区。参见例如Fundamental Immunology，Ch.7(Paul，W.编辑，第二版，Raven Press，N.Y.(1989))(其为所有目的以其整体在此引作参考)。每一轻链/重链对的可变区通常形成抗原结合位点。
术语“可变区”或“可变结构域”是指参与抗体与抗原结合的抗体重或轻链的结构域。天然抗体的重链和轻链的可变结构域通常具有相似的结构，其中每个结构域包含四个保守的框架区(FR)和三个互补决定区(CDR)(参见，例如，Kindt等Kuby Immunology，6 th ed.，W.H.Freeman and Co.91页(2007))。单个VH或VL结构域可以足以给予抗原结合特异性。此外，可以使用来自与特定抗原结合的抗体的VH或VL结构域来分离结 合所述抗原的抗体，以分别筛选互补VL或VH结构域的文库。参见，例如，Portolano等，J.Immunol.150：880-887(1993)；Clarkson等，Nature 352：624-628(1991)。在本公开中的FR和CDR是按AbM的标准来划分的，但必须指出的是，本公开中的CDR并不局限于AbM的划分方式，它还可以是本领域常规的其他任意一种划分方式，如还可以按照Chothia，Martin，Kabat，AHo和IMGT等方式来进行划分。
可变区通常表现出由三个高变区连接的相对保守的构架区(FR)的相同的一般结构，所述高变区也被称为互补决定区或CDR。通常通过构架区定位(align)来自每对的两条链的CDR，所述CDR使得抗体可结合特异性表位。两条轻链和重链可变区从N-末端到C-末端通常包含结构域FR1、CDR1、FR2、CDR2、FR3、CDR3和FR4。
“抗体片段”是指不同于完整抗体的分子，其包含完整抗体的部分，所述部分结合完整抗体结合的抗原。
“亲和力”是指分子(例如抗体)的单一结合位点与其结合配偶体(例如抗原)之间全部非共价相互作用总和的强度。除非另有说明，在用于本文时，“结合亲和力”指反映结合对的成员(例如抗体与抗原)之间1∶1相互作用的内在结合亲和力。分子X对其配偶体Y的亲和力通常可用解离常数(Kd)来表述。亲和力可通过本领域知道的常用方法来测量，包括现有技术已知以及本文中所描述的那些。
如本文所用的术语“EC 50”，也被称为“半数有效浓度”，是指在特定的暴露时间后诱导在基线和最大值之间的50％的应答的药物、抗体或毒剂的浓度。在本申请的上下文中，EC 50的单位为“nM”。
“人抗体”指具有这样的氨基酸序列的抗体，所述氨基酸序列对应于这样抗体的氨基酸序列，所述抗体由人或人细胞生成或来源于非人来源，其利用人抗体库或其它人抗体编码序列。人抗体的这种定义明确排除包含非人抗原结合残基的人源化抗体。
“人共有框架”是指这样的框架，即在选择人免疫球蛋白VL或VH框架序列中，其代表最常出现的氨基酸残基。一般而言，对人免疫球蛋白VL或VH序列的选择是从可变结构域序列的亚型中选择。一般而言，该序列的亚型是如Kabat等，Sequences of Proteins of Immunological Interest，第五版，NIH Publication 91-3242，Bethesda MD(1991)，1-3卷中的亚型。在一个实施方案中，对于VL，该亚型是如Kabat等(见上文)中的亚型κI。在一个实施方案中，对于VH，该亚型是如Kabat等(见上文)中的亚型III。
“人源化”抗体是指包含来自非人HVR的氨基酸残基和来自人FR的氨基酸残基的嵌 合抗体。在一些实施方案中，人源化抗体将包含基本上所有的至少一个、通常两个可变结构域，其中所有或基本上所有的HVR(例如，CDR)对应于非人抗体的那些，并且所有或基本上所有的FR对应于人抗体的那些。人源化抗体任选可以包含至少一部分的来源于人抗体的抗体恒定区。抗体(例如非人抗体)的“人源化形式”是指已经进行了人源化的抗体。
术语“保守取代”是指一个氨基酸被同一类别内的另一氨基酸取代，例如一个酸性氨基酸被另一酸性氨基酸取代，一个碱性氨基酸被另一碱性氨基酸取代，或一个中性氨基酸被另一中性氨基酸取代。示例性的取代如下表D所示：
表D.示例性的取代
Figure PCTCN2020125301-appb-000007
Figure PCTCN2020125301-appb-000008
氨基酸可以按照常见侧链的性质进行分组：
(1)疏水性：正亮氨酸，Met，Ala，Val，Leu，Ile；
(2)中性亲水性：Cys，Ser，Thr，Asn，Gln；
(3)酸性：Asp，Glu；
(4)碱性：His，Lys，Arg；
(5)影响链取向的残基：Gly，Pro；
(6)芳族的：Trp，Tyr，Phe。
非保守性取代需要将这些类别中之一的成员交换为另一类。
一种类型的取代变体包括取代母体抗体(例如人源化抗体)的一个或多个高变区残基。一般地，关于进一步研究所选择的得到的一种或多种变体相对于母体抗体具有某些生物学特性的改进(例如，改善)(例如，增加的亲和力、减少的免疫原性)，和/或将具有母体抗体基本上保留的特定生物学特性。一种示例性的置换变体是亲和力成熟的抗体，其可以便利地产生，例如，使用基于噬菌体的亲和力成熟技术，诸如本文所述的那些技术。简言之，将一个或多个HVR残基突变，并且将变体抗体展示在噬菌体上，并针对特定的生物学活性(例如，结合亲和力)进行筛选。
相对于参比多肽序列的“百分比(％)氨基酸序列同一性”定义为在将所述序列进行比对(并在必要时导入空位)以获取最大百分比序列同一性，且不将任何保守取代视为序列同一性的部分之后，候选序列中的氨基酸残基与参比多肽序列中的相同氨基酸残基的百分比。可使用本领域各种方法进行序列比对以便测定百分比氨基酸序列同一性，例如，使用公众可得到的计算机软件如BLAST、BLAST-2、ALIGN或MEGALIGN(DNASTAR) 软件。本领域技术人员可以决定测量比对的适宜参数，包括对所比较的序列全长获得最大比对所需的任何算法。当在本申请中提到序列同一性的百分比时，若未另外特别指出，这些百分比相对于较长序列的全长计算。相对于较长序列的全长计算适用于核酸序列和多肽序列两者。
术语“有效量”、“治疗有效量”指本发明的抗体或抗原结合片段的量或剂量，其以单一或多次剂量施用患者后，在治疗的受试者中产生预期效果，这包括受试者病症的改善(例如，一个或多个症状的改善)和/或症状进展的延迟等。“有效量”、“治疗有效量”也可以指足够降低PD-L1信号传导的量。
有效量可以由作为本领域技术人员的主治医师通过考虑以下多种因素来容易地确定：诸如哺乳动物的物种；它的大小、年龄和一般健康；涉及的具体疾病；疾病的程度或严重性；个体患者的应答；施用的具体抗体；施用模式；施用制剂的生物利用率特征；选择的给药方案；和任何伴随疗法的使用。
本文所用术语“阻断”表示存在本发明的抗体时减少PD-L1的信号传递。PD-L1介导的信号传递阻断指本发明的PD-L1单结构域抗体存在时PD-L1信号传递水平低于PD-L1的对照水平(即不存在抗体时的PD-L1信号传递水平)，降低的幅度大于或等于5％、10％、15％、20％、25％、30％、35％、40％、45％、50％、55％、60％、65％、70％、75％、80％、85％、90％、95％、99％或100％。可使用多种标准技术测量PD-L1信号传递水平，如作为非限制性实施例，测量下游基因激活和/或响应PD-L1激活的荧光素酶报告试验。本领域技术人员应理解可使用多种试验测量PD-L1信号传递水平，包括例如可商购获得的试剂盒。
术语“宿主细胞”、“宿主细胞系”和“宿主细胞培养物”可交换地使用且是指其中引入外源核酸的细胞，包括这种细胞的后代。宿主细胞包括“转化体”和“转化的细胞”，其包括初级转化的细胞和来源于其的后代，而不考虑传代的数目。后代在核酸含量上可能与亲本细胞不完全相同，而是可以包含突变。本文中包括与在最初转化的细胞中筛选或选择的具有相同功能或生物学活性的突变体后代。
术语“载体”当在本文中使用时是指能够增殖与其相连的另一个核酸的核酸分子。该术语包括作为自我复制核酸结构的载体以及结合到已经引入其的宿主细胞的基因组中的载体。一些载体能够指导与其可操作相连的核酸的表达。这样的载体在本文中被称为“表达载体”。
“个体”或“受试者”包括哺乳动物。哺乳动物包括但不限于，家养动物(例如，牛，羊， 猫，狗和马)，灵长类动物(例如，人和非人灵长类动物如猴)，兔，羊驼，以及啮齿类动物(例如，小鼠和大鼠)。在一些实施方案中，个体或受试者是人。
II.PD-L1单结构域抗体或其抗原结合片段
本发明所述的分离的PD-L1结合分子 可以是单结构域抗体或其抗原结合片段。换言之，本发明提供分离的PD-L1单结构域抗体或其抗原结合片段，其能够特异性结合PD-L1。
因此，本发明还提供以下实施方案：
1.一种分离的PD-L1单结构域抗体或其抗原结合片段，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
(i)包含SEQ ID NO：1所示氨基酸序列的CDR1；
包含与SEQ ID NO：1具有至少80％、85％、90％、95％或99％同一性的氨基酸序列的CDR1；或
包含与SEQ ID NO：1相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的CDR1；
(ii)包含SEQ ID NO：2所示氨基酸序列的CDR2；
包含与SEQ ID NO：2具有至少80％、85％、90％、95％或99％同一性的氨基酸序列的CDR2；或
包含与SEQ ID NO：2相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的CDR2；
和
(iii)包含SEQ ID NO：3或12所示氨基酸序列的CDR3；
包含与SEQ ID NO：3或12具有至少80％、85％、90％、95％或99％同一性的氨基酸序列的CDR3；或
包含与SEQ ID NO：3或12相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的CDR3。
2.根据实施方案1所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述重链可变区包含：
(i)如式RTDSNIX 1GMH所示的CDR1，其中X 1为H、F或N；
(ii)如式TIFIDX 2NTX 3所示的CDR2，其中X 2为G、L或A，X 3为I或L；和
(iii)如式DVSGYGRX 4所示的CDR3，其中X 4为A或Y。
3.根据实施方案1所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述重链可变区包含：
(i)包含SEQ ID NO：1或由SEQ ID NO：1组成的CDR1；
(ii)包含SEQ ID NO：2或由SEQ ID NO：2组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
4.根据实施方案1所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述重链可变区包含：
(i)包含SEQ ID NO：4或由SEQ ID NO：4组成的CDR1；
(ii)包含SEQ ID NO：5或由SEQ ID NO：5组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
5.根据实施方案1所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述重链可变区包含：
(i)包含SEQ ID NO：6或由SEQ ID NO：6组成的CDR1；
(ii)包含SEQ ID NO：7或由SEQ ID NO：7组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
6.根据实施方案1所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述重链可变区包含：
(i)包含SEQ ID NO：1或由SEQ ID NO：1组成的CDR1；
(ii)包含SEQ ID NO：8或由SEQ ID NO：8组成的CDR2；和
(iii)包含SEQ ID NO：9或由SEQ ID NO：9组成的CDR3。
7.根据实施方案1所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述重链可变区包含：
(i)包含SEQ ID NO：10或由SEQ ID NO：10组成的CDR1；
(ii)包含SEQ ID NO：11或由SEQ ID NO：11组成的CDR2；和
(iii)包含SEQ ID NO：12或由SEQ ID NO：12组成的CDR3。
8.根据实施方案1所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述重链可变区包含：
(i)包含SEQ ID NO：13或由SEQ ID NO：13组成的CDR1；
(ii)包含SEQ ID NO：5或由SEQ ID NO：5组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
9.根据实施方案1所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述重链可变区包含：
(i)包含SEQ ID NO：14或由SEQ ID NO：14组成的CDR1；
(ii)包含SEQ ID NO：15或由SEQ ID NO：15组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
10.根据实施方案1所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述重链可变区包含：
(i)包含SEQ ID NO：16或由SEQ ID NO：16组成的CDR1；
(ii)包含SEQ ID NO：17或由SEQ ID NO：17组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
11.根据实施方案1所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述重链可变区包含：
(i)包含SEQ ID NO：18或由SEQ ID NO：18组成的CDR1；
(ii)包含SEQ ID NO：19或由SEQ ID NO：19组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
12.根据实施方案1所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述重链可变区包含：
(i)包含SEQ ID NO：20或由SEQ ID NO：20组成的CDR1；
(ii)包含SEQ ID NO：5或由SEQ ID NO：5组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
13.一种分离的PD-L1单结构域抗体或其抗原结合片段，其特异性结合PD-L1，并 且包含重链可变区，其中所述重链可变区包含：
(i)包含SEQ ID NO：21或由SEQ ID NO：21组成的CDR1；
(ii)包含SEQ ID NO：22或由SEQ ID NO：22组成的CDR2；和
(iii)包含SEQ ID NO：23或由SEQ ID NO：23组成的CDR3。
14.一种分离的PD-L1单结构域抗体或其抗原结合片段，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
(i)包含SEQ ID NO：24或由SEQ ID NO：24组成的CDR1；
(ii)包含SEQ ID NO：25或由SEQ ID NO：25组成的CDR2；和
(iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
15.一种分离的PD-L1单结构域抗体或其抗原结合片段，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
(i)包含SEQ ID NO：26或由SEQ ID NO：26组成的CDR1；
(ii)包含SEQ ID NO：27或由SEQ ID NO：27组成的CDR2；和
(iii)包含SEQ ID NO：23或由SEQ ID NO：23组成的CDR3。
16.一种分离的PD-L1单结构域抗体或其抗原结合片段，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
(i)包含SEQ ID NO：28或由SEQ ID NO：28组成的CDR1；
(ii)包含SEQ ID NO：29或由SEQ ID NO：29组成的CDR2；和
(iii)包含SEQ ID NO：23或由SEQ ID NO：23组成的CDR3。
17.一种分离的PD-L1单结构域抗体或其抗原结合片段，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
(i)包含SEQ ID NO：30或由SEQ ID NO：30组成的CDR1；
(ii)包含SEQ ID NO：31或由SEQ ID NO：31组成的CDR2；和
(iii)包含SEQ ID NO：23或由SEQ ID NO：23组成的CDR3。
18.一种分离的PD-L1单结构域抗体或其抗原结合片段，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含SEQ ID NO：36-52中任一条所示的重链可变区氨基酸序列中的3个CDR。
19.根据实施方案1-18中任一项所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述重链可变区还包含FR区，所述FR区包含FR1、FR2、FR3和FR4，并且与CDR1、CDR2和CDR3在所述重链可变区上间隔排列形成从N端到C端为FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4的结构。
20.根据实施方案19所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述FR区包含：
(a)包含SEQ ID NO：53所示氨基酸序列的FR1；
包含与SEQ ID NO：53具有至少90％、95％或99％同一性的氨基酸序列的FR1；或
包含与SEQ ID NO：53相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR1；
(b)包含SEQ ID NO：54所示氨基酸序列的FR2；
包含与SEQ ID NO：54具有至少90％、95％或99％同一性的氨基酸序列的FR2；或
包含与SEQ ID NO：54相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR2；
(c)包含SEQ ID NO：55所示氨基酸序列的FR3；
包含与SEQ ID NO：55具有至少90％、95％或99％同一性的氨基酸序列的FR3；或
包含与SEQ ID NO：55相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR3；
和
(d)包含SEQ ID NO：56所示氨基酸序列的FR4；
包含与SEQ ID NO：56具有至少90％、95％或99％同一性的氨基酸序列的FR4；或
包含与SEQ ID NO：56相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR4。
21.根据实施方案19所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中 所述FR区包含：
(a)包含SEQ ID NO：57所示氨基酸序列的FR1；
包含与SEQ ID NO：57具有至少90％、95％或99％同一性的氨基酸序列的FR1；或
包含与SEQ ID NO：57相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR1；
(b)包含SEQ ID NO：58所示氨基酸序列的FR2；
包含与SEQ ID NO：58具有至少90％、95％或99％同一性的氨基酸序列的FR2；或
包含与SEQ ID NO：58相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR2；
(c)包含SEQ ID NO：59所示氨基酸序列的FR3；
包含与SEQ ID NO：59具有至少90％、95％或99％同一性的氨基酸序列的FR3；或
包含与SEQ ID NO：59相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR3；
和
(d)包含SEQ ID NO：60所示氨基酸序列的FR4；
包含与SEQ ID NO：60具有至少90％、95％或99％同一性的氨基酸序列的FR4；或
包含与SEQ ID NO：60相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR4。
22.根据实施方案19所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述FR区包含：
(a)包含SEQ ID NO：61所示氨基酸序列的FR1；
包含与SEQ ID NO：61具有至少90％、95％或99％同一性的氨基酸序列的FR1；或
包含与SEQ ID NO：61相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR1；
(b)包含SEQ ID NO：58所示氨基酸序列的FR2；
包含与SEQ ID NO：58具有至少90％、95％或99％同一性的氨基酸序列的FR2；或
包含与SEQ ID NO：58相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR2；
(c)包含SEQ ID NO：59所示氨基酸序列的FR3；
包含与SEQ ID NO：59具有至少90％、95％或99％同一性的氨基酸序列的FR3；或
包含与SEQ ID NO：59相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR3；
和
(d)包含SEQ ID NO：60所示氨基酸序列的FR4；
包含与SEQ ID NO：60具有至少90％、95％或99％同一性的氨基酸序列的FR4；或
包含与SEQ ID NO：60相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR4。
23.根据实施方案1-22中任一项所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述重链可变区包含SEQ ID NO：36-52中任一项所示的氨基酸序列或由SEQ ID NO：36-52中任一项所示的氨基酸序列组成。
24.根据实施方案1-22中任一项所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述重链可变区包含与SEQ ID NO：36-52中任一项所示的氨基酸序列具有至少80％、85％、90％、95％或99％同一性并且保留特异性结合PD-L1的能力的氨基酸序列。
25.根据实施方案1-22中任一项所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述重链可变区包含与SEQ ID NO：36-52中任一项所示的氨基酸序列相比具有一处或多处氨基酸的添加、缺失和/或取代(例如，保守性取代)并且保留特异性结 合PD-L1的能力的氨基酸序列，其中所述一处或多处氨基酸的添加、缺失和/或取代(例如，保守性取代)不超过五处，优选地不超过三处。
26.根据实施方案1-25中任一项所述的分离的PD-L1单结构域抗体或其抗原结合片段，其中所述PD-L1结合分子为骆驼源抗体、人源化抗体、亲和力成熟的抗体或成药性改造后分子。
27.根据实施方案1-26中任一项所述的分离的PD-L1单结构域抗体或其抗原结合片段，所述重链可变区与另一分子融合，所述另一分子选自免疫球蛋白(例如IgG)的Fc结构域、抗体、抗体的抗原结合片段、抗体-药物偶联物、抗体样分子、抗体样分子的抗原结合片段或荧光蛋白。
28.根据实施方案27所述的分离的PD-L1单结构域抗体或其抗原结合片段，所述重链可变区与人IgG(如人IgG1或人IgG4)的Fc结构域融合。
29.一种分离的核酸分子，其包含编码实施方案1-28中任一项所述的分离的PD-L1单结构域抗体或其抗原结合片段的核苷酸序列。
30.一种载体，其包含实施方案29所述的核酸分子。
31.一种宿主细胞，其包含实施方案30所述的载体。
32.一种药物组合物，其包含有效量的实施方案1-28中任一项所述的PD-L1单结构域抗体或其抗原结合片段以及药学上可接受的载体。
33.一种制备实施方案1-28中任一项所述的PD-L1单结构域抗体或其抗原结合片段的方法，所述方法包括以下步骤：
-在宿主细胞中使编码实施方案1-28中任一项所述的PD-L1单结构域抗体或其抗原结合片段的核苷酸序列表达，以产生所述PD-L1单结构域抗体或其抗原结合片段；和
-从所述宿主细胞分离所述PD-L1单结构域抗体或其抗原结合片段。
34.一种用于预防或治疗受试者中与PD-L1相关的疾病的方法，所述方法包括向所述受试者施用治疗有效量的实施方案1-28中任一项所述的PD-L1单结构域抗体或其抗原结合片段或施用有效量的包含实施方案1-27中任一项所述的PD-L1单结构域抗体或其抗原结合片段的药物组合物。
35.一种用于调节受试者的免疫应答的方法，其包括向受试者施用治疗有效量的实施方案1-28中任一项所述的PD-L1单结构域抗体或其抗原结合片段或施用有效量的包含实施方案1-28中任一项所述的PD-L1单结构域抗体或其抗原结合片段的药物组合物， 使得受试者中的免疫应答受到调节。
36.根据实施方案34或35所述的方法，其中所述受试者为哺乳动物，优选小鼠或人，更优选为人。
37.根据实施方案36所述的方法，其中所述与PD-L1相关的疾病选自肾细胞癌、非小细胞肺癌、膀胱癌、尿路上皮癌、微卫星不稳定型实体瘤。
38.根据实施方案34或35所述的方法，其中所述方法还包括向受试者联合施用有效量的第二药物，其中所述第二药物是用于治疗与PD-L1相关的疾病的化疗剂、放疗剂或者生物大分子药物。
39.根据实施方案38所述的方法，其中所述生物大分子药物例如是通过T细胞识别攻击肿瘤细胞的各种单克隆抗体药，例如利妥昔单抗、西妥昔单抗与曲妥珠单抗。
40.一种用于预防或治疗受试者中与PD-L1相关的疾病的试剂盒，其包含容器，所述容器包含至少一种实施方案1-29中任一项所述的PD-L1单结构域抗体或其抗原结合片段。
41.根据实施方案1-29中任一项所述的PD-L1单结构域抗体或其抗原结合片段，其用于预防或治疗受试者中与PD-L1相关的疾病。
42.根据实施方案1-29中任一项所述的PD-L1单结构域抗体或其抗原结合片段，其用于调节受试者的免疫应答。
43.根据实施方案1-29中任一项所述的PD-L1单结构域抗体或其抗原结合片段在制备用于调节受试者的免疫应答的药物组合物中的用途。
44.根据实施方案1-29中任一项所述的PD-L1单结构域抗体或其抗原结合片段在制备用于预防或治疗受试者中与PD-L1相关的疾病的药物组合物中的用途。
45.根据实施方案43或44所述的用途，其中所述受试者为哺乳动物，优选小鼠或人，更优选为人。
46.根据实施方案45所述的用途，其中所述与PD-L1相关的疾病选自肾细胞癌、非小细胞肺癌、膀胱癌、尿路上皮癌、微卫星不稳定型实体瘤。
实施例
通过参考以下实施例将更容易地理解本文一般地描述的本发明，这些实施例是以举例说明的方式提供的，并且不旨在限制本发明。
本领域技术人员应该理解，除非另外注明，以下实施例中所用的试剂、质粒、细胞等均为可商购获得的产品。
实施例1 稳定表达PD-L1的细胞株的构建
在本实施例中本发明人分别构建了表达人PD-L1、猴PD-L1、鼠PD-L1的CHO-s细胞，并制备了罗氏公司的对照抗体。
1.1对照抗体制备
全基因合成对照抗体-Atezolizumab(罗氏)的轻链和重链基因序列(基因合成供应方：通用生物)，对照抗体表达采用的是ExpiCHO瞬转表达系统(购自赛默飞世尔)，培养基为ExpiCHO TM Expression Medium(Gibco，A29100-01)，转染试剂盒为ExpiFectamine TM CHO Transfection Kit(Gibco，A29129)。
具体方法如下：通过分子克隆构建Atezolizumab抗体轻链和重链基因的ExpiCHO表达质粒，转染前一天将ExpiCHO细胞(购自Gibco A29127)进行传代，在25ml细胞培养物体系内，将构建好的质粒25μg(含有质量比为2∶1的轻链编码基因、重链编码基因的质粒混合物)与转染试剂混合之后滴加入25ml ExpiCHO细胞培养物中，充分混匀，于37℃表达18-22小时后，根据试剂盒内说明添加补料培养基，补料后，细胞置于32℃培养，转染后第5天，添加第二次补料，并将细胞置于32℃培养，10-12天之后，将表达好的细胞混悬液高速离心取上清，所得上清经0.22μm滤膜过滤后采用Protein A/G亲和层析柱亲和纯化方法进行纯化，用100mM甘氨酸盐(pH3.0)洗脱目的蛋白，接着用1M Tris-HCl中和至pH7.0。小量取样后经SDS-PAGE鉴定后分装、入库冻存。
对照抗体KN035(氨基酸序列见序列表SEQ ID NO：35)的制备方法如下：
全基因合成对照抗体KN035全基因序列，通过分子克隆构建KN035抗体基因的ExpiCHO表达质粒，转染前一天将ExpiCHO细胞(购自Gibco A29127)进行传代，在25ml细胞培养物体系内，将构建好的质粒25μg与转染试剂混合后，按照上述对照抗体-Atezolizumab制备的方法进行转染，并表达出抗体。
1.2稳定细胞株的构建
分别构建表达人PD-L1(gi号：NP_054862.1)、鼠PD-L1(gi号：NP_068693)和恒河猴PD-L1(gi号：ABO33163.1)全长蛋白的重组载体质粒，采用电转法将构建好的质粒导入CHO-s细胞(购自赛默飞世尔)和A375黑色素瘤细胞株(ATCC，CRL-1619) 中。通过筛选分别得到以上三种物种PD-L1蛋白的高表达CHO-s细胞株以及高表达人PD-L1的A375细胞株(PD-L1-A375)。
1.2.1表达人PD-1和PD-L1胞外域蛋白的质粒构建
分别通过基因合成技术合成出含有人PD-L1、鼠PD-L1和恒河猴PD-L1全长蛋白基因序列的表达载体，连接后导入大肠杆菌，挑取大肠杆菌单克隆后测序得到正确的质粒克隆，进行质粒抽提并再次测序。
1.2.2表达PD-1和PD-L1蛋白的CHO-s细胞株构建
1.2.2.1电转
使用CD-CHO无血清培养基(Gibco，10743029)培养维持CHO-s细胞，电转前一天将细胞传代至5×10 6/mL，第二天使用电转试剂盒(Invitrogen，Neon TM Kit，MPK10096)和电转仪(Invitrogen，NeonTM Transfection System，MP922947)将构建好的质粒分别导入CHO-s细胞中。将电转后的细胞加入3mL CD-CHO培养基中，放置于37℃二氧化碳培养箱中培养48小时。
1.2.2.2细胞铺板与培养
将电转后的CHO-s细胞按2000个细胞/孔铺板96孔细胞培养板，加入终浓度30μM/mL L-蛋氨酸亚砜亚胺(L-Methionine sulfoximine，MSX)(Millipore，GSS-1015-F)，保持体积为细胞培养体积为100μL/孔和I×GS补充物(Sigma，58672C)，放置于37℃二氧化碳培养箱中培养，10天后补充加入含30μM MSX和I×GS补充物的培养基50μL。
1.2.2.3克隆鉴定与细胞扩培
将长出的克隆挑取，转移至24孔细胞培养板中培养。利用FACS方法对细胞株进行鉴定，选择表达量高的克隆进行扩培和冻存。相关FACS鉴定方法如下：
1)首先收集空CHO-s细胞及各个克隆CHO-s细胞2×10 5个，300g离心去上清，将细胞用配制好的200μL FACS缓冲液(1×PBS+2％FBS)重悬在96-孔圆底板中；
2)将96孔圆底板300g离心5min，去上清；
3)向对应孔中加入抗PD-L1抗体稀释液或阴性对照抗体稀释液，用排枪将细胞吹匀并放置于4℃孵育30分钟；
4)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL FACS缓冲液 并使用排枪重悬细胞；
5)重复步骤4)两次，300g离心去上清；
6)加入PE标记的抗-人IgG Fc流式抗体(Abcam，ab98596)，用排枪将细胞吹匀并放置于4℃孵育30分钟；
7)300g离心去上清，加入FACS缓冲液并重悬细胞；
8)重复步骤7)两次，向孔中加入FACS缓冲液，每孔200μL，重悬细胞，通过流式细胞仪(Beckman，CytoFLEX AOO-1-1102)检测。
1.2.3表达PD-L1的A375细胞株制备
以1.2.2.1中电转CHO-s细胞同样的方法制备A375细胞株的PD-L1高表达细胞株(PD-L1-A375)，用于A375细胞株的动物模型构建。
实施例2 动物免疫与血清效价检测
2.1动物免疫
购买PD-L1(NP_054862.1)胞外域蛋白(义翘神州，10084-H05H)免疫2只羊驼(南昌大佳科技)。每只羊驼每次免疫500μg，每2周免疫一次，共免疫4次。
2.2血清效价检测
待羊驼免疫结束后取羊驼血清进行免疫效价检测。
免疫效价测定是通过ELISA方法测定免疫血清针对重组蛋白PD-L1(义翘神州，10084-H05H)的结合能力，并根据结合抗体的效价进行免疫效果的判定。
具体方法如下所述：
2.2.1抗原包被：在免疫效价测定的前一天，将抗原重组蛋白PD-L1用PBS稀释至终浓度2μg/mL，获得稀释液。将30μl获得的稀释液加入到ELISA板中，4℃包被过夜。在免疫效价测定当日用PBS润洗三遍，后用含有5％脱脂牛奶的PBST室温封闭两小时，再用PBS润洗三遍。
2.2.2血清稀释：在另外一块稀释板上将未经免疫接种的阴性血清和免疫后血清用PBS进行稀释，首孔200倍稀释，然后后续7个孔采用3倍梯度稀释。
2.2.3抗体反应：稀释好的血清加入到第一块ELISA板中，37℃孵育1h，PBS洗两遍后以1∶5000加入二抗羊抗骆驼科IgG抗体(购自南京金斯瑞)。
2.2.4显色读数：PBS清洗上述二抗3次后，加入显色液显色5分钟，加入终止液后，通过酶标仪(Molecular Devices，SpecterMax 190)在OD450下读板，结果见表1。
表1.不同稀释比例下的ELISA显色实验结果
稀释比例 阴性血清 NSY004 NSY005
1∶2000 0.209 2.582 2.163
1∶4000 0.133 2.286 2.216
1∶8000 0.093 1.923 2.131
1∶16000 0.052 1.817 1.868
1∶32000 0.054 1.337 1.218
1∶64000 0.048 1.048 0.792
1∶128000 0.042 0.761 0.587
1∶256000 0.048 0.404 0.473
其中，NSY004和NSY005两列分别为两只羊驼免疫后的血清稀释不同倍数后的ELISA显色实验结果，阴性血清为未免疫的羊驼血清ELISA实验结果。根据表1的结果，可见两只羊驼的免疫效价IgG效价均达到了256000，免疫效果较好，可用于下一步的外周血免疫抗体库构建。
实施例3 羊驼免疫库构建及初步筛选
动物免疫结束后，取羊驼新鲜血液50mL，通过Ficoll-Paque密度梯度分离液(GE，17144003S)分离外周血单核细胞(Peripheral Blood Mononuclear Cell，PBMC)，进行抗人PD-L1抗体噬菌体羊驼免疫库构建。
具体方法如下：
将采集的羊驼血用PBS以1∶1(v/v)的比例稀释，取Ficoll-Paque密度梯度分离液15ml缓缓加入50ml离心管中，将离心管倾斜并沿管壁缓慢加入稀释好的羊驼血30mL，使得两种液体保持清晰的分离界面。4℃离心20min，保持加速度为升3降0。离心之后，整个液面分为四层，上层为血浆混合物，下层为红细胞和粒细胞，中层为Ficoll-Paque PLUS，在上、中层交界处有以PBMC为主的白色狭窄带，即PBMC细胞层。小心使用移液枪吸取中间的PBMC细胞转移至新的50mL离心管中。用PBS润洗两遍，4℃，1500rpm水平离心10min，最后用1.5ml PBS重悬，并通过显微镜计数。
将分离的PBMC细胞提取RNA，通过反转录试剂盒(TaKaRa，6210A)将提取的RNA反转录成cDNA。由于羊驼抗体的分子形式不同于普通抗体，其不含轻链而且重链不含CH1，因此首先在VH前端和CH2上通过设计普通引物，PCR得到两个不同大小的片段，通过割胶回收较小的目的片段。然后通过比对常见的VHH所有种系(Germline)的氨基酸序列，设计出两端分别含有NcoI和NotI酶切位点的Germline特异性简并引物，从而以回收产物为模板扩增所有的VHH基因，最后通过双酶切和连接将目的抗体基因片段插入至噬菌体展示用载体上，需要指出的是的，该表达载体上VHH基因的C端融合在噬菌体表达载体中的GIII基因。连接产物通过回收试剂盒(Omega，D6492-02)回收，最后通过电转仪(Bio-Rad，MicroPulser)转化至感受态大肠杆菌SS320中，并涂布于氨苄抗性的2-YT固体平板。为了计算库容，通过取10μl库的菌液进行10倍梯度稀释，每个稀释梯度取2μl点在平板上，计算在平板上形成的克隆来计算所有电转化形成的总克隆数，即库容量。此免疫库库容量为1×10 9。
基于此库容容量，取10倍于库容的菌量(约20OD)加入到新鲜的2-YT液体培养基中，调整培养基的加入用量使得菌液稀释液初始OD值为0.05。置于37℃，220rpm培养至对数生长期，此时以50倍于细菌数的数量加入VSCM13辅助噬菌体，充分混匀，静置30min，然后在220rpm条件下培养1h，通过10000rpm离心5min后置换至羧苄青霉素/卡那霉素双抗性2-YT培养基中，并于30℃，220rpm培养过夜。次日，13000g离心10min，其上清通过加入20％PEG/NaCl溶液，沉淀得到羊驼免疫抗体库对应的噬菌体，经PBS润洗一次之后，用于目标靶点PD-L1抗体筛选。
噬菌体筛选使用的是重组PD-L1蛋白，采用磁珠筛选和免疫管筛选两种方法，具体方法如下所述。
3.1磁珠筛选
基于将生物素标记的重组PD-L1蛋白结合到卵白素偶联的磁珠(购自赛默飞世尔，货号：11205D)上进行筛选，首先用生物素标记重组人PD-L1蛋白(生物素标记方法见Roche公司的生物素蛋白标记试剂盒说明书，货号：11418165001)，将生物素标记的PD-L1蛋白和磁珠孵育，使得PD-L1蛋白结合于磁珠上。将结合有PD-L1抗原的磁珠和具有纳米抗体展示的噬菌体库室温孵育2小时，经PBST洗涤6-8次后，去除非特异性吸附的噬菌体，加入胰蛋白酶(Gibco)轻轻混匀20min，以洗脱特异性结合人PD-L1蛋白的纳米抗体展示噬菌体。接着将洗脱的噬菌体侵染对数期的SS320菌体(Lucigen， MC1061F)，并将噬菌体侵染的SS320菌体涂布于羧苄青霉素抗性平板，37℃过夜培养，第二天收集菌体。采用SS320菌体制备噬菌体，制备方法详见如上文库噬菌体制备方法。最终得到的噬菌体继续用于第二轮的筛选，在第二轮筛选结束时采用胰蛋白酶方式进行洗脱。将第二轮筛选得到的噬菌体用于第三轮筛选，在第三轮筛选结束时采用胰蛋白酶进行洗脱。如此反复，通过每轮随机挑选的10个克隆进行序列分析。结果显示，经过3轮的筛选后得到的单克隆噬菌体，测序后的单克隆，不同克隆的基因序列出现重复，证明序列富集明显。
3.2免疫管筛选
免疫管筛选是基于将抗原包被在免疫管表面，筛选和目的抗原结合的抗体展示噬菌体。筛选前一天提前使用重组人PD-L1蛋白包被免疫管，将结合有PD-L1抗原的免疫管和具有纳米抗体展示的噬菌体库室温孵育2小时，经PBST洗涤6-8次后，去除非特异性吸附的噬菌体，加入胰蛋白酶(Gibco)轻轻混匀20min，以洗脱特异性结合人PD-L1蛋白的纳米抗体展示噬菌体。接着将洗脱的噬菌体侵染对数期的SS320菌体(Lucigen，MC1061 F)，并将噬菌体侵染的SS320菌体涂布于羧苄青霉素抗性平板，37℃过夜培养，第二天收集菌体。采用SS320菌体制备噬菌体，制备方法详见如上文库噬菌体制备方法。最终得到的噬菌体继续用于第二轮的筛选。在第二轮筛选结束时采用Trypsin方式进行洗脱。将第二轮筛选得到的噬菌体用于第三轮筛选，在第三轮筛选结束时采用Trypsin方式进行洗脱。如此反复，通过每轮随机挑选的10个克隆进行测序后并进行序列分析。结果显示，经过3轮的筛选，测序后的单克隆，不同克隆的基因序列出现重复，证明序列富集明显。
对两种不同筛选方法获得的噬菌体库进行单克隆筛选，分别挑取磁珠筛选和免疫管筛选的第三轮产物中的阳性克隆。具体方法如下：
筛选前一天将重组人PD-L1蛋白包被到96孔ELISA板上，第二天于96孔板中制备诱导噬菌体上清，通过噬菌体ELISA筛选针对人PD-L1重组蛋白的阳性克隆，后挑取所有阳性克隆测序分析，将序列唯一的克隆制备裂解液，制备方法如下：前一天将该克隆的菌液以1∶100接种50mL，37℃恒温摇床振荡培养14h，10000g常温离心5min，使用1mL PH 9.0含有benzonase核酸酶的Tris-HCl缓冲液重悬细菌，冰上裂解30min，4℃ 10000g离心10min，收集上清即得到阳性克隆裂解液。
将制备好的阳性克隆裂解液进一步在流式水平上验证，筛选到特异性识别人PD-L1 的候选抗体。流式水平验证方法如下：
1)首先收集培养好的人PD-L1-CHO细胞，300g离心去上清，将细胞用配制好的FACS缓冲液重悬，计数并将细胞悬液密度调整为2×10 6个/mL；
2)将PD-L1-CHO细胞以100μL每孔加入96孔圆底板，300g离心去上清；
3)向对应孔中加入梯度稀释的候选抗体裂解液和对照抗体稀释液，用排枪将细胞吹匀并放置于4℃孵育30分钟；
4)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL FACS缓冲液并使用排枪重悬细胞；
5)重复步骤4)两次，300g离心去上清；
6)加入PE标记的流式抗体(金斯瑞)，用排枪将细胞吹匀并放置于4℃孵育30分钟；
7)300g离心去上清，加入FACS缓冲液并重悬细胞；
8)重复步骤7)两次，向孔中加入FACS缓冲液，每孔200μL，重悬细胞，通过流式细胞仪(Beckman，CytoFLEX AOO-1-1102)检测。
抗PD-L1 VHH裂解液样本结合亲和力筛选的结果显示在图1中。
从图1可以看出，所示的克隆号的VHH分子对表达PD-L1的CHO细胞都有一定的亲和力。由于本检测实验只是定性和半定量，无法确认哪一个克隆号的VHH抗体分子亲和力比较好，需要进行进一步实验确认。
将制备好的阳性克隆裂解液进一步在流式水平上进行阻断筛选，筛选到特异性识别人PD-L1并阻断其与PD-1蛋白结合的候选抗体。流式水平验证方法如下：
1)首先收集培养好的人PD-L1-CHO细胞，300g离心去上清，将细胞用配制好的FACS缓冲液重悬，计数并将细胞悬液密度调整为2×10 6/mL；
2)将PD-L1-CHO细胞以100μL每孔加入96孔圆底板，300g离心去上清；
3)向对应孔中加入梯度稀释获得的浓度梯度分别为1∶1、1∶5和1∶25的候选抗体裂解液和对照抗体稀释液，用排枪将细胞吹匀并放置于4℃孵育30分钟；
4)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
5)重复步骤4)两次，300g离心去上清；
6)向对应孔中加入PD-1-Fc蛋白稀释液(1μg/mL)100μL，重悬细胞并将细胞放置于4℃孵育30分钟；
7)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
8)重复步骤7)两次，300g离心去上清；
9)加入PE标记的抗-人IgG Fc流式抗体(Abcam)，用排枪将细胞吹匀并放置于4℃孵育30分钟；
10)300g离心去上清，加入FACS缓冲液并重悬细胞；
11)重复步骤10)两次，向孔中加入FACS缓冲液，每孔200μL，重悬细胞，通过流式细胞仪(Beckman，CytoFLEX AOO-1-1102)检测。
抗PD-L1抗体候选分子的封闭实验筛选结果如图2所示，通过ELISA和FACS等方法的初步筛选，可见筛选到的抗体序列制备的抗体裂解液中含有对PD-L1结合到PD1上的反应有封闭效果的抗体，本发明人筛选到10个有良好亲和力及阻断活性的候选分子。
实施例4 嵌合VHH-Fc抗体的产生和表达
将筛选获得的阳性VHH候选抗体与人IgG1Fc段融合，采用阳性VHH基因序列的C端连接到人IgG1Fc片段基因序列的N端的方式构建融合表达载体，将该融合表达载体质粒转化ExpiCHO细胞，诱导表达得到融合了Fc片段的VHH-Fc嵌合抗体蛋白。
抗体表达采用的是ExpiCHO瞬转表达系统，培养基为(Gibco，A29100-01)，转染试剂盒为(Gibco，A29129)。具体方法如下：转染前一天将ExpiCHO细胞进行传代，在25ml体系内，将构建好的质粒25μg与转染试剂混合之后滴加入25ml ExpiCHO细胞培养物中，充分混匀，于37℃表达18-22小时后，根据试剂盒内说明添加补料培养基，补料后，细胞置于32℃培养，转染后第5天，添加第二次补料，并将细胞置于32℃培养，10-12天之后，将表达好的细胞混悬液高速离心取上清，所得上清经0.22μm过滤后采用Protein A/G亲和纯化方法进行纯化，用100mM甘氨酸盐(pH3.0)洗脱目的蛋白，接着用1M Tris-HCl中和。
实施例5 嵌合VHH-Fc抗体细胞水平的亲和活性验证
对获得的VHH-Fc候选抗体进行评价，采用FACS方法检测其与细胞上PD-L1蛋白 的结合活性，具体方法如下：
1)收集培养好的人PD-L1-CHO细胞，300g离心去上清，将细胞用配制好的FACS缓冲液重悬，计数并将细胞悬液密度调整为2×10 6个/mL；
2)将PD-L1-CHO细胞以100μL每孔加入96孔圆底板，300g离心去上清；
3)向对应孔中加入梯度稀释的候选抗体稀释液和对照抗体稀释液，用排枪将细胞吹匀并放置于4℃孵育30分钟；
4)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
5)重复步骤4)两次，300g离心去上清；
6)加入PE标记的抗-人IgG Fc流式抗体(Abcam，ab98596)，用排枪将细胞吹匀并放置于4℃孵育30分钟；
7)300g离心去上清，加入FACS缓冲液并重悬细胞；
8)重复步骤10)两遍，向孔中加入FACS缓冲液，每孔200μL，重悬细胞，通过流式细胞仪(Beckman，CytoFLEX AOO-1-1102)检测。
如表2所示，通过FACS实验，本发明人筛选到2个有高亲和力的纳米抗体候选分子(NB22D-21和NB22gb-10)，亲和力均高于或与对照抗体相似。
表2.抗体的EC50
克隆编号 EC50(μg/mL)
NB22D-21 0.39
NB22gb-10 0.39
KN035(对照) 0.39
Atezolizumab(对照) 0.83
实施例6 嵌合VHH-Fc抗体阻断PD-1的活性验证
对获得的VHH-Fc候选抗体进行评价，采用FACS方法检测其对PD-1/PD-L1的阻断活性，具体方法如下：
1)收集培养好的人PD-L1-CHO细胞，300g离心去上清，将细胞用配制好的FACS 缓冲液重悬，计数并将细胞悬液密度调整为2×10 6/mL；
2)将PD-L1-CHO细胞以100μL每孔加入96孔圆底板，300g离心去上清；
3)向对应孔中加入梯度稀释的候选抗体稀释液和对照抗体稀释液，用排枪将细胞吹匀并放置于4℃孵育30分钟；
4)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
5)重复步骤4)两次，300g离心去上清；
6)向对应孔中加入生物素标记的PD-1-Fc蛋白稀释液(1μg/mL)100μL，重悬细胞并将细胞放置于4℃孵育30分钟；
7)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μLFACS并使用排枪重悬细胞；
8)重复步骤7)两次，300g离心去上清；
9)加入PE标记的链霉抗生物素蛋白(streptavidin，eBioscience，12-4317-87)，用排枪将细胞吹匀并放置于4℃孵育30分钟；
10)300g离心去上清，加入FACS缓冲液并重悬细胞；
11)重复步骤10)两遍，向孔中加入FACS缓冲液，每孔200μL，重悬细胞，通过流式细胞仪(Beckman，CytoFLEX AOO-1-1102)上机检测。
如表3所示，通过FACS实验，本发明人验证了实施例5中克隆编号为NB22D-21和NB22gb-10的2个纳米抗体候选分子同时拥有高阻断活性，其阻断活性均高于对照抗体或与对照抗体相似。
表3.抗体的IC50
克隆编号 IC50(μg/mL)
NB22D-21 0.41
NB22gb-10 0.54
KN035(对照) 0.39
Atezolizumab(对照) 0.86
实施例7 嵌合VHH-Fc抗体阻断CD80的活性验证
对获得的VHH-Fc候选抗体进行评价，采用FACS方法检测其对CD80/PD-L1的阻断活性，具体方法如下：
1)收集培养好的人PD-L1-CHO细胞，300g离心去上清，将细胞用配制好的FACS缓冲液重悬，计数并将细胞悬液密度调整为2×10 6/mL；
2)将PD-L1-CHO细胞以100μL每孔加入96孔圆底板，300g离心去上清；
3)向对应孔中加入梯度稀释的候选抗体稀释液和对照抗体稀释液，用排枪将细胞吹匀并放置于4℃孵育30分钟；
4)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
5)重复步骤4)两次，300g离心去上清；
6)向对应孔中加入生物素标记的CD80蛋白稀释液(1μg/mL)100μL，重悬细胞并将细胞放置于4℃孵育30分钟；
7)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
8)重复步骤7)两次，300g离心去上清；
9)加入PE标记的链霉抗生物素蛋白(eBioscience，12-4317-87)，用排枪将细胞吹匀并放置于4℃孵育30分钟；
10)300g离心去上清，加入FACS缓冲液并重悬细胞；
11)重复步骤10)两次，向孔中加入FACS缓冲液，每孔200μL，重悬细胞，通过流式细胞仪(Beckman，CytoFLEX AOO-1-1102)检测。
如表4所示，通过FACS实验，本发明人验证了实施例5中克隆编号为NB22D-21和NB22gb-10的2个纳米抗体候选分子同时拥有高阻断活性，其阻断活性均高于对照抗体或与对照抗体相似。
表4.抗体的IC50
克隆编号 IC50(μg/mL)
NB22D-21 0.7081
NB22gb-10 0.7651
KN035(对照) 0.6307
Atezolizumab(对照) 0.9077
实施例8 嵌合VHH-Fc抗体在肿瘤细胞上的结合活性
为了评价VHH-Fc候选抗体在人黑色素瘤细胞系A375细胞(ATCC，CRL-1619)上的结合活性，采用FACS方法检测其与细胞上PD-L1蛋白的结合活性，具体方法如下：
1)用含0.25％EDTA的Trypsin消化A375细胞，收集细胞300g离心去上清，将细胞用配制好的FACS缓冲液重悬，计数并将细胞悬液密度调整为2×10 6个/mL；
2)将A375细胞以100μL每孔加入96孔圆底板，300g离心去上清；
3)向对应孔中加入梯度稀释的候选抗体稀释液和对照抗体稀释液，用排枪将细胞吹匀并放置于4℃孵育30分钟；
4)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
5)重复步骤4)两次，300g离心去上清；
6)向对应孔中加入各个候选抗体和对照抗体稀释液(1μg/mL)100μL，重悬细胞并将细胞放置于4℃孵育30分钟；
7)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
8)重复步骤7)两次，300g离心去上清；
9)加入PE标记的抗-生物素(anti-biotin)流式抗体(Abcam)，用排枪将细胞吹匀并放置于4℃孵育30分钟；
10)300g离心去上清，加入FACS缓冲液并重悬细胞；
11)重复步骤10)两次，向孔中加入FACS缓冲液，每孔200μL，重悬细胞，通过流式细胞仪(Beckman，CytoFLEX AOO-1-1102)检测，检测结果如图3所示。
从图3可以看出，克隆编号为NB22D-21和NB22gb-10的2个纳米抗体候选分子在人黑色素瘤细胞系A375细胞上的结合活性与对照抗体相当。
实施例9 嵌合VHH-Fc抗体结合鼠、猴PD-L1的活性验证
为了评价VHH-Fc候选抗体与猴、鼠PD-L1的交叉结合活性，采用FACS方法检测 其与细胞上PD-L1蛋白的结合活性，具体方法如下：
1)收集培养的小鼠PD-L1-CHO细胞和猴PD-L1-CHO细胞，300g离心去培养基，将细胞用配制好的FACS缓冲液重悬，计数并将细胞悬液密度调整为2×10 6/mL；
2)分别将小鼠PD-L1-CHO细胞和猴PD-L1-CHO细胞以100μL每孔加入96孔圆底板，300g离心去上清；
3)向对应孔中加入梯度稀释的候选抗体稀释液和对照抗体稀释液，用排枪将细胞吹匀并放置于4℃孵育30分钟；
4)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
5)重复步骤4)两次，300g离心去上清；
6)向对应孔中加入生物素标记的PD-1-Fc蛋白稀释液(1μg/mL)100μL，重悬细胞并将细胞放置于4℃孵育30分钟；
7)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
8)重复步骤7)两次，300g离心去上清；
9)加入PE标记的抗-生物素(anti-biotin)流式抗体(Abcam)，用排枪将细胞吹匀并放置于4℃孵育30分钟；
10)300g离心去上清，加入FACS缓冲液并重悬细胞；
11)重复步骤10)两次，向孔中加入FACS缓冲液，每孔200μL，重悬细胞，通过流式细胞仪(Beckman，CytoFLEX AOO-1-1102)检测。
人鼠交叉反应检测结果显示克隆编号为NB22D-21的纳米抗体候选分子有一定的鼠PD-L1结合活性。
人猴交叉反应的检测结果参见表5，从中可以看出，克隆编号为NB22D-21和NB22gb-10的2个纳米抗体候选分子均有很好的识别猴PD-L1的活性。
表5.EC50值
克隆编号 EC50(μg/mL)
NB22D-21 0.25
NB22gb-10 0.20
KN035(对照) 0.21
Atezolizumab(对照) 0.33
实施例10 嵌合VHH-Fc抗体结合PD-L1的特异性检测
为了确认候选分子结合PD-L1蛋白的特异性，采用ELISA法检测候选分子结合B7家族其他蛋白的活性，具体方法如下：
实验前一天向ELISA板中加入30μL终浓度为2μg/mL的B7-H1(即，PDL1)、B7-H2、B7-H3、B7-H4、B7-DC(以上蛋白均购自义翘神州公司，货号分别为10084-HNAH、11559-H08H、11188-H08H、10738-H08H、10292-H08H-B)等蛋白稀释液，4℃孵育过夜；第二天使用PBST润洗ELISA板3遍，随后加入150μL 5％PBSM封闭ELISA板，常温孵育2小时；再用PBST洗板3遍，接着将30μL候选抗体和对照抗体的稀释液加入ELISA板中，常温孵育1小时；用PBST洗板3遍，加入1∶7000稀释的抗-人IgG Fc-HRP二抗，每孔30μL，常温孵育30分钟；用PBST洗板6遍后加入TMB显色，最后加入2M HCl终止反应，通过酶标仪(Molecular Devices，SpecterMax 190)在450nM波长下读值，其结果显示在表6和图4中。
抗体分子的特异性结合反应实验验证结果如表6和图4所示。
表6.候选分子结合PD-L1蛋白的特异性
克隆/蛋白 B7-H1 B7-H2 B7-H3 B7-H4 B7-DC
NB22D-21 + N/A N/A N/A N/A
NB22-gb-10 + N/A N/A N/A N/A
KN035 + N/A N/A N/A N/A
Atezolizumab + N/A N/A N/A N/A
+：表示检出结合活性；
N/A：表示未检出结合活性。
从表6和图4的结果可以看出，克隆编号为NB22D-21和NB22gb-10的2个纳米抗体候选分子对B7-H1以外的B7家族分子没有结合活性，只对B7-H1有结合活性，这个结合特异性与对照抗体一致。
实施例11 嵌合VHH-Fc抗体的体外生物学活性验证
为了确认候选分子在体外刺激T细胞激活的能力，本发明人在体外建立了混合淋巴 细胞反应体系，具体方法如下：
使用美天旎分选试剂盒(Miltenyibiotec，130-050-201)体外分选CD14阳性的单核细胞和CD4阳性T细胞，体外使用100ng/mL IL-4和100ng/mL GM-CSF诱导培养7天将单核细胞诱导成为树突状细胞(Dendritic cell，DC)，再将CD4阳性T细胞与DC以10∶1的细胞数比例混合，向细胞中加入梯度稀释的候选抗体和对照抗体，37℃细胞培养箱中培养5天，培养72小时后取细胞上清，PBS稀释后使用IL-2ELISA试剂盒检测培养上清中的IL-2分泌量；培养5天后取细胞上清，PBS稀释后使用IFN-γELISA试剂盒检测培养上清中的IFN-γ分泌量。
通过检测IL-2的分泌量，本发明人得到抗体分子的混合淋巴细胞反应测试验证结果，其如图5所示。从图5可以看出，本发明的纳米抗体候选分子可以激活免疫反应。
实施例12 抗体人源化改造
为了降低分子在体内的免疫原性，本发明人对候选分子进行了人源化设计。分别使用Discovery Studio和
Figure PCTCN2020125301-appb-000009
Antibody Modeling，采用同源建模方法建模，选取5-10个最优结构解，Loop区域一般使用同源建模方法建模，如CDR氨基酸序列比对结果显示低于50％同一性，则使用从头建模方法搭建CDR3结构模型。使用PDB BLAST调取序列最接近的10个抗体晶体结构模型(结构分辨率高于2.5埃)，对比自动建模模型，选取最优的结构模型。本发明人对NB22D-21分子进行了抗体人源化改造，得到了两个人源化的分子，这两个人源化改造后的分子编号分别为NB22D-21-huVH1和NB22D-21-huVH2。
实施例13 人源化改造后的衍生分子结合人PD-L1-CHO细胞
为了检测人源化对分子结合人PD-L1抗原活性的影响，本发明人用FACS对候选分子及其人源化改造后的衍生分子进行了检测。
1)收集培养好的人PD-L1-CHO细胞，300g离心去上清，将细胞用配制好的FACS缓冲液重悬，计数并将细胞悬液密度调整为2×10 6个/mL；
2)将PD-L1-CHO细胞以100μL每孔加入96孔圆底板，300g离心去上清；
3)向对应孔中加入梯度稀释的候选抗体稀释液和对照抗体稀释液，用排枪将细胞吹匀并放置于4℃孵育30分钟；
4)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
5)重复步骤4)两次，300g离心去上清；
6)加入PE标记的抗-人IgG Fc流式抗体(Abcam，ab98596)，用排枪将细胞吹匀并放置于4℃孵育30分钟；
7)300g离心去上清，加入FACS缓冲液并重悬细胞；
8)重复步骤7)两次，向孔中加入FACS缓冲液，每孔200μL，重悬细胞，通过流式细胞仪(Beckman，CytoFLEX AOO-1-1102)检测，结果如图6所示。
从图6可以看出，人源化后得到的衍生分子(即，NB22D-21-huVH1和NB22D-21-huVH2)与人PD-L1结合的亲和力和其母本分子(即，NB22D-21)相似。
实施例14 人源化改造后的衍生分子结合鼠PD-L1-CHO细胞
为了检测人源化对分子结合鼠PD-L1抗原交叉活性的影响，本发明人用FACS对候选分子进行了检测。
1)收集培养好的鼠PD-L1-CHO细胞，300g离心去上清，将细胞用配制好的FACS缓冲液重悬，计数并将细胞悬液密度调整为2×10 6个/mL；
2)将鼠PD-L1-CHO细胞以100μL每孔加入96孔圆底板，300g离心去上清；
3)向对应孔中加入梯度稀释的候选抗体稀释液和对照抗体稀释液，用排枪将细胞吹匀并放置于4℃孵育30分钟；
4)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
5)重复步骤4)两次，300g离心去上清；
6)加入PE标记的抗-人IgG Fc流式抗体(Abcam，ab98596)，用排枪将细胞吹匀并放置于4℃孵育30分钟；
7)300g离心去上清，加入FACS缓冲液并重悬细胞；
8)重复步骤7)两次，向孔中加入FACS缓冲液，每孔200μL，重悬细胞，通过流式细胞仪(Beckman，CytoFLEXAOO-1-1102)检测，结果参见图7和图8。
从图7可以看出，人源化改造后得到的衍生分子中，NB22D-21-huVH1与鼠PD-L1结合的亲和力要优于母本分子(即，NB22D-21)。
具体而言，从图7可以看出，相对于母本分子NB22D-21以及对照分子KN035，人源化改造后得到的衍生分子NB22D-21-huVH1具有非常好的结合鼠PD-L1蛋白的活性；选取其中KN035和NB22D-21-huVH1的流式峰图(如图8所示)，从中可以清楚地看出：分别使用20μg/mL的KN035和NB22D-21-huVH1结合鼠PD-L1过表达细胞，FACS检测数据表明KN035不能识别CHO细胞表面的鼠PD-L1(图8A)，而NB22D-21-huVH1 能够很好地识别CHO细胞表面的鼠PD-L1(图8B)(注：每个图中间的分界线为设定的荧光强度阈值位置)。
实施例15 人源化改造后的衍生分子阻断PD-1的活性验证
对人源化后获得的衍生分子进行评价，采用FACS方法检测其对PD-1/PD-L1的阻断活性，具体方法如下：
1)收集培养好的人PD-L1-CHO细胞，300g离心去上清，将细胞用配制好的FACS缓冲液重悬，计数并将细胞悬液密度调整为2×10 6/mL。
2)将PD-L1-CHO细胞以100μL每孔加入96孔圆底板，300g离心去上清；
3)向对应孔中加入梯度稀释的候选抗体稀释液和对照抗体稀释液，用排枪将细胞吹匀并放置于4℃孵育30分钟；
4)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
5)重复步骤4)两次，300g离心去上清；
6)向对应孔中加入生物素标记的PD-1-Fc蛋白稀释液(1μg/mL)100μL，重悬细胞并将细胞放置于4℃孵育30分钟；
7)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL FACS并使用排枪重悬细胞；
8)重复步骤7)两次，300g离心去上清；
9)加入PE标记的链霉抗生物素蛋白(streptavidin，eBioscience，12-4317-87)，用排枪将细胞吹匀并放置于4℃孵育30分钟；
10)300g离心去上清，加入FACS缓冲液并重悬细胞；
11)重复步骤10)两次，向孔中加入FACS缓冲液，每孔200μL，重悬细胞，通过流式细胞仪(Beckman，CytoFLEX AOO-1-1102)检测，结果如图9所示。
从图9可以看出，人源化改造后得到的衍生分子(即，NB22D-21-huVH1和NB22D-21-huVH2)阻断PD-1蛋白结合PD-L1的活性与其母本分子(即，NB22D-21)和阳性对照KN035相当。
实施例16 人源化分子的亲和力成熟
为了提升抗体分子结合人PD-L1抗原的亲和力和阻断活性，本发明人对人源化改造后获得的抗体衍生分子进行了亲和力成熟设计。
亲和力成熟采用单点饱和突变、多点组合突变、链置换等方法，采用Trim引物技术对CDR区定向设计引物，构建亲和力成熟抗体库，并利用噬菌体展示技术对亲和力成熟后的分子进行筛选。获得单克隆后制备VHH裂解液，并采用FACS检测克隆的亲和与阻断活性。通过筛选我们获得了4个可能优于母本的克隆，分别是SY01-201、SY01-208、SY01-NB-004和SY01-NB-027-M。
具体的实验结果如图10和图11所示，从其细胞裂解液的定性/半定量结果可以大致看出，SY01-201、SY01-208、SY01-NB-004和SY01-NB-027-M四个分子的结合活性和阻断活性均与母本NB22D-21分子相似。
实施例17 人源化分子的成药性改造
为了优化分子的成药性，避免潜在翻译后修饰位点对蛋白质折叠、活性以及功能的影响，本发明人对人源化改造后获得的抗体衍生分子NB22D-21-huVH2进行了成药性改造设计。
成药性改造采用点突变对潜在翻译后修饰位点进行随机突变，构建成药性改造抗体库，并利用噬菌体展示技术对成药性改造后的分子进行筛选。获得单克隆后制备VHH裂解液，并采用FACS检测克隆在PD-L1-CHO上的阻断活性。
通过初步筛选，本发明人得到10个成药性改造后的变体分子：SY01-D21-3、SY01-D21-4、SY01-D21-5、SY01-D21-6、SY01-D21-8、SY01-D21-17、SY01-D21-21、SY01-D21-24、SY01-D21-38和SY01-D21-47(在图15中分别简写为3、4、5、6、8、17、21、24、38和47，母本分子为NB22D-21-huVH2，简写为D21-Vh2，同种型对照(isotype)为人IgG1)，通过进一步筛选，本发明人获得了5个可能优于母本的克隆，分别是SY01-D21-4、SY01-D21-8、SY01-D21-17、SY01-D21-24和SY01-D21-47。
实验结果如图15所示，从其细胞裂解液的定性/半定量结果可以看出，SY01-D21-4、SY01-D21-8、SY01-D21-17和SY01-D21-24这4个成药性改造候选分子的阻断活性均与母本分子NB22D-21-huVH2相似。另外，由于SY01-D21-47的细胞表达量不高，因此未选用该克隆进行后续检测。
实施例18 成药性候选克隆的全长构建及样品生产
将筛选获得的阳性VHH候选抗体SY01-D21-4、SY01-D21-8、SY01-D21-17和SY01-D21-24与人IgG1Fc片段融合，采用阳性VHH基因序列的C端连接到人IgG1Fc片段基因序列的N端的方式构建融合表达载体，将该融合表达载体质粒转化ExpiCHO 细胞，诱导表达得到融合了Fc片段的4种VHH-Fc嵌合抗体蛋白，分别称为NB22D-21-4、NB22D-21-8、NB22D-21-17和NB22D-21-24。
抗体表达采用的是ExpiCHO瞬转表达系统，培养基为(Gibco，A29100-01)，转染试剂盒为(Gibco，A29129)。具体方法如下：转染前一天将ExpiCHO细胞进行传代，在25ml体系内，将构建好的质粒25μg与转染试剂混合之后滴加入25ml ExpiCHO细胞培养物中，充分混匀，于37℃表达18-22小时后，根据试剂盒内说明添加补料培养基，补料后，细胞置于32℃培养，转染后第5天，添加第二次补料，并将细胞置于32℃培养，10-12天之后，将表达好的细胞混悬液高速离心取上清，所得上清经0.22μm过滤后采用Protein A/G亲和纯化方法进行纯化，用100mM甘氨酸盐(pH3.0)洗脱目的蛋白，接着用1M Tris-HCl中和。
实施例19 成药性改造后的候选抗体结合人和猴PD-L1的活性验证
对成药性改造后获得的4个VHH-Fc候选抗体进行评价，采用FACS方法检测其与细胞上人及猴PD-L1蛋白的结合活性，具体方法如下：
1)收集培养好的人和猴PD-L1-CHO细胞，300g离心去上清，将细胞用配制好的FACS缓冲液重悬，计数并将细胞悬液密度调整为2×10 6个/mL；
2)将人和猴PD-L1-CHO细胞分别以100μL每孔加入96孔圆底板，300g离心去上清；
3)向对应孔中加入梯度稀释的候选抗体稀释液和对照抗体稀释液，用排枪将细胞吹匀并放置于4℃孵育30分钟；
4)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
5)重复步骤4)两次，300g离心去上清；
6)加入PE标记的抗-人IgG Fc流式抗体(Abcam，ab98596)，用排枪将细胞吹匀并放置于4℃孵育30分钟；
7)300g离心去上清，加入FACS缓冲液并重悬细胞；
8)重复步骤10)两遍，向孔中加入FACS缓冲液，每孔200μL，重悬细胞，通过流式细胞仪(Beckman，CytoFLEX AOO-1-1102)检测。
如表7所示，比较4个候选分子在人和猴PD-L1-CHO上的结合活性，本发明人筛选到2个对人和猴PD-L1均有较高亲和力的纳米抗体候选分子NB22D-21-4以及NB22D-21-24。
表7.抗体的EC50
Figure PCTCN2020125301-appb-000010
实施例20 成药性改造后的候选抗体阻断PD-1的活性验证
对获得的VHH-Fc候选抗体进行评价，采用FACS方法检测其对PD-1/PD-L1的阻断活性，具体方法如下：
1)收集培养好的人PD-L1-CHO细胞，300g离心去上清，将细胞用配制好的FACS缓冲液重悬，计数并将细胞悬液密度调整为2×10 6/mL；
2)将PD-L1-CHO细胞以100μL每孔加入96孔圆底板，300g离心去上清；
3)向对应孔中加入梯度稀释的候选抗体稀释液和对照抗体稀释液，用排枪将细胞吹匀并放置于4℃孵育30分钟；
4)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
5)重复步骤4)两次，300g离心去上清；
6)向对应孔中加入生物素标记的PD-1-Fc蛋白稀释液(1μg/mL)100μL，重悬细胞并将细胞放置于4℃孵育30分钟；
7)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μLFACS并使用排枪重悬细胞；
8)重复步骤7)两次，300g离心去上清；
9)加入PE标记的链霉抗生物素蛋白(streptavidin，eBioscience，12-4317-87)，用排枪将细胞吹匀并放置于4℃孵育30分钟；
10)300g离心去上清，加入FACS缓冲液并重悬细胞；
11)重复步骤10)两遍，向孔中加入FACS缓冲液，每孔200μL，重悬细胞，通过流式细胞仪(Beckman，CytoFLEX AOO-1-1102)上机检测。
如表8所示，通过FACS实验，本发明人验证了实施例19中克隆编号为NB22D-21-4以及NB22D-21-24的2个纳米抗体候选分子同时拥有高阻断活性，其阻断活性均高于NB22D-21-huVH2抗体。
表8.抗体的IC50
克隆编号 IC50(μg/mL)
NB22D-21-huVH2 1.00
NB22D-21-4 0.30
NB22D-21-24 0.20
实施例21 成药性改造后的候选抗体结合PD-L1的特异性检测
为了确认成药性改造后的候选分子结合PD-L1蛋白的特异性，采用FACS法检测候选分子结合细胞的特异性，具体分为两部分，第一部分具体方法如下：
1)收集培养好的Jurkat和Raji细胞，300g离心去上清，将细胞用配制好的FACS缓冲液(缓冲液成分：1＊PBS+5％FBS+2％BSA)重悬，计数并将细胞悬液密度调整为2×10 6个/mL；
2)将Jurkat和Raji细胞分别以100μL每孔加入96孔圆底板，300g离心去上清；
3)向对应孔中加入梯度稀释的候选抗体稀释液和对照抗体稀释液，用排枪将细胞吹匀并放置于4℃孵育30分钟；
4)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
5)重复步骤4)四次，300g离心去上清；
6)加入PE标记的抗-人IgG Fc流式抗体(Abcam，ab98596)，用排枪将细胞吹匀并放置于4℃孵育30分钟；
7)300g离心去上清，加入FACS缓冲液并重悬细胞；
8)重复步骤10)两遍，向孔中加入FACS缓冲液，每孔200μL，重悬细胞，通过流式细胞仪(Beckman，CytoFLEX AOO-1-1102)检测。
如下表9，根据FACS检测结果，本发明人将阳性和阴性分别用“+”(表示有结合)和“-”(表示无结合)表示，根据表9可知，在NB22D-21-4及NB22D-21-24克隆中，前 者在两种细胞上均没有非特异性结合，而后者均有较高的非特异性结合，且对照抗体没有显示出非特异性结合。
表9.抗体的非特异性结合
克隆/细胞 Jurkat Raji
NB22D-21-huVH2 - -
NB22D-21-4 - -
NB22D-21-24 + +
KN035(对照) - -
Atezolizumab(对照) - -
第二部分实验中，本发明人利用FACS方法对NB22D-21-4克隆结合B7家族蛋白的特异性进行了检测，具体方法如下：
1)收集培养好的B7-H2，B7-H4，B7-H5细胞，300g离心去上清，将细胞用配制好的FACS缓冲液(缓冲液成分：1＊PBS+5％FBS+2％BSA)重悬，计数并将细胞悬液密度调整为2×10 6个/mL；
2)将B7-H2，B7-H4，B7-H5细胞分别以100μL每孔加入96孔圆底板，300g离心去上清；
3)向对应孔中加入梯度稀释的候选抗体稀释液和对照抗体稀释液，用排枪将细胞吹匀并放置于4℃孵育30分钟；
4)将孵育后的细胞混合液300g离心去上清，向对应孔中加入200μL并使用排枪重悬细胞；
5)重复步骤4)四次，300g离心去上清；
6)加入PE标记的抗-人IgG Fc流式抗体(Abcam，ab98596)，用排枪将细胞吹匀并放置于4℃孵育30分钟；
7)300g离心去上清，加入FACS缓冲液并重悬细胞；
8)重复步骤10)两遍，向孔中加入FACS缓冲液，每孔200μL，重悬细胞，通过流式细胞仪(Beckman，CytoFLEX AOO-1-1102)检测。
如下表10，根据FACS检测结果，本发明人将阳性和阴性分别用“+”(表示有结合)和“-”(表示无结合)表示，根据表10可知，NB22D-21-4在多种细胞上均没有非特异性结合，且对照抗体没有显示出非特异性结合。
表10.抗体与B7家族蛋白的特异性
克隆/细胞 B7-H2 B7-H3 B7-H4 B7-H5
NB22D-21-huVH2 - - - -
NB22D-21-4 - - - -
KN035(对照) - - - -
实施例22 NB22D-21-4抗体的体外MLR活性验证
为了确认候选分子在体外刺激T细胞激活的能力，本发明人在体外建立了混合淋巴细胞反应体系，具体方法如下：
使用美天旎分选试剂盒(Miltenyibiotec，130-050-201)体外分选CD14阳性的单核细胞和CD4阳性T细胞，体外使用100ng/mL IL-4和100ng/mL GM-CSF诱导培养7天将单核细胞诱导成为树突状细胞(Dendritic cell，DC)，再将CD4阳性T细胞与DC以10∶1的细胞数比例混合，向细胞中加入梯度稀释的候选抗体和对照抗体，37℃细胞培养箱中培养5天，培养72小时后取细胞上清，PBS稀释后使用IL-2 ELISA试剂盒检测培养上清中的IL-2分泌量；培养5天后取细胞上清，PBS稀释后使用IFN-γ ELISA试剂盒检测培养上清中的IFN-γ分泌量。
通过检测IFN-γ和IL-2的分泌量，本发明人得到抗体分子的混合淋巴细胞反应测试验证结果，其如图16所示。从图16可以看出，本发明的纳米抗体候选分子NB22D-21-4可以激活免疫反应。
实施例23 候选抗体的第二次亲和力成熟
为了进一步提升抗体分子结合鼠PD-L1抗原的亲和力及阻断活性等，我们对人源化改造后获得的抗体衍生分子进行了亲和力成熟设计。
本轮亲和力成熟采用单点饱和突变方法，采用Trim引物技术对CDR区定向设计引物，构建亲和力成熟抗体库，并继续利用噬菌体展示技术对亲和力成熟后的分子进行筛选。利用鼠抗原分别对亲和力成熟库进行海选及初筛，获得单克隆后构建表达全长抗体，并采用FACS检测候选克隆的亲和力、人鼠交叉与阻断活性。通过筛选我们获得了5个活性优于 原始母本的克隆，分别是NB22D-21-45-106、NB22D-21-123、NB22D-21-154、NB22D-21-94和NB22D-21-109。
具体的实验结果如图12、图13和图14所示，从结果可以看出，NB22D-21-45-106、NB22D-21-123、NB22D-21-154、NB22D-21-94和NB22D-21-109五个分子的结合活性和阻断活性均与对照NB22D21-4样本高度相似或更优，并且鼠交叉活性也要好于母本分子NB22D-21-huVH2。而从实施例15和实施例17的试验结果中可以看出，NB22D21-4分子与母本NB22D-21分子相比结合活性和阻断活性更优，可以得出母本分子经过亲和力成熟后得到的5个分子亲和性和阻断活性与母本NB22D-21分子高度相似或更优，且鼠交叉活性优于母本分子和对照抗体KN035。
本领域技术人员将进一步认识到，在不脱离其精神或中心特征的情况下，本发明可以以其他具体形式来实施。由于本发明的前述描述仅公开了其示例性实施方案，应该理解的是，其他变化被认为是在本发明的范围内。因此，本发明不限于在此详细描述的特定实施方案。相反，应当参考所附权利要求来指示本发明的范围和内容。

Claims (37)

  1. 一种分离的PD-L1结合分子，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
    (i)包含SEQ ID NO：1所示氨基酸序列的CDR1；
    包含与SEQ ID NO：1具有至少80％、85％、90％、95％或99％同一性的氨基酸序列的CDR1；或
    包含与SEQ ID NO：1相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的CDR1；
    (ii)包含SEQ ID NO：2所示氨基酸序列的CDR2；
    包含与SEQ ID NO：2具有至少80％、85％、90％、95％或99％同一性的氨基酸序列的CDR2；或
    包含与SEQ ID NO：2相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的CDR2；
    和
    (iii)包含SEQ ID NO：3或12所示氨基酸序列的CDR3；
    包含与SEQ ID NO：3或12具有至少80％、85％、90％、95％或99％同一性的氨基酸序列的CDR3；或
    包含与SEQ ID NO：3或12相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的CDR3。
  2. 根据权利要求1所述的分离的PD-L1结合分子，其中所述重链可变区包含：
    (i)如式RTDSNIX 1GMH所示的CDR1，其中X 1为H、F或N；
    (ii)如式TIFIDX 2NTX 3所示的CDR2，其中X 2为G、L或A，X 3为I或L；和
    (iii)如式DVSGYGRX 4所示的CDR3，其中X 4为A或Y。
  3. 根据权利要求1所述的分离的PD-L1结合分子，其中所述重链可变区包含：
    (i)包含SEQ ID NO：1或由SEQ ID NO：1组成的CDR1；
    (ii)包含SEQ ID NO：2或由SEQ ID NO：2组成的CDR2；和
    (iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
  4. 根据权利要求1所述的分离的PD-L1结合分子，其中所述重链可变区包含：
    (i)包含SEQ ID NO：4或由SEQ ID NO：4组成的CDR1；
    (ii)包含SEQ ID NO：5或由SEQ ID NO：5组成的CDR2；和
    (iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
  5. 根据权利要求1所述的分离的PD-L1结合分子，其中所述重链可变区包含：
    (i)包含SEQ ID NO：6或由SEQ ID NO：6组成的CDR1；
    (ii)包含SEQ ID NO：7或由SEQ ID NO：7组成的CDR2；和
    (iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
  6. 根据权利要求1所述的分离的PD-L1结合分子，其中所述重链可变区包含：
    (i)包含SEQ ID NO：1或由SEQ ID NO：1组成的CDR1；
    (ii)包含SEQ ID NO：8或由SEQ ID NO：8组成的CDR2；和
    (iii)包含SEQ ID NO：9或由SEQ ID NO：9组成的CDR3。
  7. 根据权利要求1所述的分离的PD-L1结合分子，其中所述重链可变区包含：
    (i)包含SEQ ID NO：10或由SEQ ID NO：10组成的CDR1；
    (ii)包含SEQ ID NO：11或由SEQ ID NO：11组成的CDR2；和
    (iii)包含SEQ ID NO：12或由SEQ ID NO：12组成的CDR3。
  8. 根据权利要求1所述的分离的PD-L1结合分子，其中所述重链可变区包含：
    (i)包含SEQ ID NO：13或由SEQ ID NO：13组成的CDR1；
    (ii)包含SEQ ID NO：5或由SEQ ID NO：5组成的CDR2；和
    (iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
  9. 根据权利要求1所述的分离的PD-L1结合分子，其中所述重链可变区包含：
    (i)包含SEQ ID NO：14或由SEQ ID NO：14组成的CDR1；
    (ii)包含SEQ ID NO：15或由SEQ ID NO：15组成的CDR2；和
    (iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
  10. 根据权利要求1所述的分离的PD-L1结合分子，其中所述重链可变区包含：
    (i)包含SEQ ID NO：16或由SEQ ID NO：16组成的CDR1；
    (ii)包含SEQ ID NO：17或由SEQ ID NO：17组成的CDR2；和
    (iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
  11. 根据权利要求1所述的分离的PD-L1结合分子，其中所述重链可变区包含：
    (i)包含SEQ ID NO：18或由SEQ ID NO：18组成的CDR1；
    (ii)包含SEQ ID NO：19或由SEQ ID NO：19组成的CDR2；和
    (iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
  12. 根据权利要求1所述的分离的PD-L1结合分子，其中所述重链可变区包含：
    (i)包含SEQ ID NO：20或由SEQ ID NO：20组成的CDR1；
    (ii)包含SEQ ID NO：5或由SEQ ID NO：5组成的CDR2；和
    (iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
  13. 一种分离的PD-L1结合分子，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
    (i)包含SEQ ID NO：21或由SEQ ID NO：21组成的CDR1；
    (ii)包含SEQ ID NO：22或由SEQ ID NO：22组成的CDR2；和
    (iii)包含SEQ ID NO：23或由SEQ ID NO：23组成的CDR3。
  14. 一种分离的PD-L1结合分子，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
    (i)包含SEQ ID NO：24或由SEQ ID NO：24组成的CDR1；
    (ii)包含SEQ ID NO：25或由SEQ ID NO：25组成的CDR2；和
    (iii)包含SEQ ID NO：3或由SEQ ID NO：3组成的CDR3。
  15. 一种分离的PD-L1结合分子，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
    (i)包含SEQ ID NO：26或由SEQ ID NO：26组成的CDR1；
    (ii)包含SEQ ID NO：27或由SEQ ID NO：27组成的CDR2；和
    (iii)包含SEQ ID NO：23或由SEQ ID NO：23组成的CDR3。
  16. 一种分离的PD-L1结合分子，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
    (i)包含SEQ ID NO：28或由SEQ ID NO：28组成的CDR1；
    (ii)包含SEQ ID NO：29或由SEQ ID NO：29组成的CDR2；和
    (iii)包含SEQ ID NO：23或由SEQ ID NO：23组成的CDR3。
  17. 一种分离的PD-L1结合分子，其特异性结合PD-L1，并且包含重链可变区，其中所述重链可变区包含：
    (i)包含SEQ ID NO：30或由SEQ ID NO：30组成的CDR1；
    (ii)包含SEQ ID NO：31或由SEQ ID NO：31组成的CDR2；和
    (iii)包含SEQ ID NO：23或由SEQ ID NO：23组成的CDR3。
  18. 根据权利要求1-17中任一项所述的分离的PD-L1结合分子，其中所述重链可变区还包含FR区，所述FR区包含FR1、FR2、FR3和FR4，并且与CDR1、CDR2和CDR3在所述重链可变区上间隔排列形成从N端到C端为FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4的结构。
  19. 根据权利要求18所述的分离的PD-L1结合分子，其中所述FR区包含：
    (a)包含SEQ ID NO：53所示氨基酸序列的FR1；
    包含与SEQ ID NO：53具有至少90％、95％或99％同一性的氨基酸序列的FR1；或
    包含与SEQ ID NO：53相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR1；
    (b)包含SEQ ID NO：54所示氨基酸序列的FR2；
    包含与SEQ ID NO：54具有至少90％、95％或99％同一性的氨基酸序列的FR2；或
    包含与SEQ ID NO：54相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR2；
    (c)包含SEQ ID NO：55所示氨基酸序列的FR3；
    包含与SEQ ID NO：55具有至少90％、95％或99％同一性的氨基酸序列的FR3；或
    包含与SEQ ID NO：55相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR3；
    和
    (d)包含SEQ ID NO：56所示氨基酸序列的FR4；
    包含与SEQ ID NO：56具有至少90％、95％或99％同一性的氨基酸序列的FR4；或
    包含与SEQ ID NO：56相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR4。
  20. 根据权利要求18所述的分离的PD-L1结合分子，其中所述FR区包含：
    (a)包含SEQ ID NO：57所示氨基酸序列的FR1；
    包含与SEQ ID NO：57具有至少90％、95％或99％同一性的氨基酸序列的FR1；或
    包含与SEQ ID NO：57相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR1；
    (b)包含SEQ ID NO：58所示氨基酸序列的FR2；
    包含与SEQ ID NO：58具有至少90％、95％或99％同一性的氨基酸序列的FR2；或
    包含与SEQ ID NO：58相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR2；
    (c)包含SEQ ID NO：59所示氨基酸序列的FR3；
    包含与SEQ ID NO：59具有至少90％、95％或99％同一性的氨基酸序列的FR3；或
    包含与SEQ ID NO：59相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR3；
    和
    (d)包含SEQ ID NO：60所示氨基酸序列的FR4；
    包含与SEQ ID NO：60具有至少90％、95％或99％同一性的氨基酸序列的FR4；或
    包含与SEQ ID NO：60相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR4。
  21. 根据权利要求18所述的分离的PD-L1结合分子，其中所述FR区包含：
    (a)包含SEQ ID NO：61所示氨基酸序列的FR1；
    包含与SEQ ID NO：61具有至少90％、95％或99％同一性的氨基酸序列的FR1； 或
    包含与SEQ ID NO：61相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR1；
    (b)包含SEQ ID NO：58所示氨基酸序列的FR2；
    包含与SEQ ID NO：58具有至少90％、95％或99％同一性的氨基酸序列的FR2；或
    包含与SEQ ID NO：58相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR2；
    (c)包含SEQ ID NO：59所示氨基酸序列的FR3；
    包含与SEQ ID NO：59具有至少90％、95％或99％同一性的氨基酸序列的FR3；或
    包含与SEQ ID NO：59相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR3；
    和
    (d)包含SEQ ID NO：60所示氨基酸序列的FR4；
    包含与SEQ ID NO：60具有至少90％、95％或99％同一性的氨基酸序列的FR4；或
    包含与SEQ ID NO：60相比具有不超过2个(如0个、1个、2个)氨基酸的添加、缺失和/或取代的差异的氨基酸序列的FR4。
  22. 根据权利要求1-17中任一项所述的分离的PD-L1结合分子，其中所述重链可变区包含SEQ ID NO：36-52中任一项所示的氨基酸序列或由SEQ ID NO：36-52中任一项所示的氨基酸序列组成。
  23. 根据权利要求1-17中任一项所述的分离的PD-L1结合分子，其中所述重链可变区包含与SEQ ID NO：36-52中任一项所示的氨基酸序列具有至少80％、85％、90％、95％或99％同一性并且保留特异性结合PD-L1的能力的氨基酸序列。
  24. 根据权利要求1-17中任一项所述的分离的PD-L1结合分子，其中所述重链可变区包含与SEQ ID NO：36-52中任一项所示的氨基酸序列相比具有一处或多处氨基酸的添加、缺失和/或取代(例如，保守性取代)并且保留特异性结合PD-L1的能力的氨基酸序列，其中所述一处或多处氨基酸的添加、缺失和/或取代(例如，保守性取代)不超过五处，优选地不超过三处。
  25. 根据权利要求1-17中任一项所述的分离的PD-L1结合分子，其中所述PD-L1结合分子为骆驼源抗体、人源化抗体、亲和力成熟的抗体或成药性改造后分子。
  26. 根据权利要求1-17中任一项所述的分离的PD-L1结合分子，其中所述PD-L1结合分子为单结构域抗体或其抗原结合片段。
  27. 根据权利要求1-17中任一项所述的分离的PD-L1结合分子，所述重链可变区与另一分子融合，所述另一分子选自免疫球蛋白(例如IgG)的Fc结构域、抗体、抗体的抗原结合片段、抗体-药物偶联物、抗体样分子、抗体样分子的抗原结合片段或荧光蛋白。
  28. 根据权利要求27所述的分离的PD-L1结合分子，所述重链可变区与人IgG(如人IgG1或人IgG4)的Fc结构域融合。
  29. 一种分离的核酸分子，其包含编码权利要求1-17中任一项所述的分离的PD-L1结合分子的核苷酸序列。
  30. 一种载体，其包含权利要求29所述的核酸分子。
  31. 一种宿主细胞，其包含权利要求30所述的载体。
  32. 一种药物组合物，其包含有效量的权利要求1-17中任一项所述的PD-L1结合分子以及药学上可接受的载体。
  33. 一种制备权利要求1-17中任一项所述的PD-L1结合分子的方法，所述方法包括以下步骤：
    -在宿主细胞中使编码权利要求1-17中任一项所述的PD-L1结合分子的核苷酸序列表达，以产生所述PD-L1结合分子；和
    -从所述宿主细胞分离所述PD-L1结合分子。
  34. 一种用于预防或治疗受试者中与PD-L1相关的疾病的方法，所述方法包括向所述受试者施用治疗有效量的权利要求1-17中任一项所述的PD-L1结合分子。
  35. 根据权利要求34所述的方法，其中所述受试者为小鼠或人，优选为人。
  36. 根据权利要求34所述的方法，其中所述与PD-L1相关的疾病选自肾细胞癌、非小细胞肺癌、膀胱癌、尿路上皮癌、微卫星不稳定型实体瘤。
  37. 一种用于预防或治疗受试者中与PD-L1相关的疾病的试剂盒，其包含容器，所述容器包含至少一种权利要求1-28中任一项所述的PD-L1结合分子。
PCT/CN2020/125301 2019-10-30 2020-10-30 Pd-l1结合分子 Ceased WO2021083335A1 (zh)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP2022525333A JP7738551B2 (ja) 2019-10-30 2020-10-30 Ｐｄ－ｌ１結合分子
US17/772,323 US20230002494A1 (en) 2019-10-30 2020-10-30 Pd-l1 binding molecule
EP20882932.5A EP4059962A4 (en) 2019-10-30 2020-10-30 Pd-l1 binding molecule
KR1020227016606A KR20220087488A (ko) 2019-10-30 2020-10-30 Pd-l1 결합 분자

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CN201911044297.0 2019-10-30
CN201911044297.0A CN112745391B (zh) 2019-10-30 2019-10-30 Pd-l1结合分子
CN202010765530.0A CN111848800B (zh) 2020-07-31 2020-07-31 Pd-l1单结构域抗体及其用途
CN202010765530.0 2020-07-31

Publications (1)

Publication Number Publication Date
WO2021083335A1 true WO2021083335A1 (zh) 2021-05-06

Family

ID=75715820

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/125301 Ceased WO2021083335A1 (zh) 2019-10-30 2020-10-30 Pd-l1结合分子

Country Status (5)

Country Link
US (1) US20230002494A1 (zh)
EP (1) EP4059962A4 (zh)
JP (1) JP7738551B2 (zh)
KR (1) KR20220087488A (zh)
WO (1) WO2021083335A1 (zh)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106397592A (zh) * 2015-07-31 2017-02-15 苏州康宁杰瑞生物科技有限公司 针对程序性死亡配体(pd-l1)的单域抗体及其衍生蛋白
CN107216389A (zh) * 2016-03-18 2017-09-29 苏州纳洛迈生物科技有限公司 抗pd-l1纳米抗体及其编码序列和用途
WO2018024237A1 (zh) * 2016-08-04 2018-02-08 信达生物制药(苏州)有限公司 抗pd-l1纳米抗体及其应用
WO2018133873A1 (zh) * 2017-01-23 2018-07-26 苏州康宁杰瑞生物科技有限公司 Pd-l1结合多肽或化合物

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109096396B (zh) * 2017-06-20 2022-01-04 华兰生物工程股份有限公司 一种抗pd-l1人源化纳米抗体及其应用
EP3664829A4 (en) * 2017-08-09 2021-05-05 Orionis Biosciences, Inc. LIAISON OFFICERS AT PD-1 AND PD-L1
CN109485726B (zh) * 2017-09-13 2022-07-08 和迈生物科技有限公司 放射性标记抗纳米抗体在癌症的预后、诊断中的应用
EP3710480A4 (en) * 2017-11-17 2021-12-15 Nanjing Legend Biotech Co., Ltd. SINGLE-DOMAIN ANTIBODIES AND VARIANTS OF THEM DIRECTED AGAINST PD-L1
CN110144010B9 (zh) * 2018-02-14 2021-01-05 上海洛启生物医药技术有限公司 阻断型pd-l1驼源单域抗体及其用途
CA3092421A1 (en) * 2018-03-01 2019-09-06 Vrije Universiteit Brussel Human pd-l1-binding immunoglobulins
CN110256564A (zh) * 2019-07-05 2019-09-20 石河子大学 Pd-l1抗原免疫羊驼制备pd-l1纳米抗体的方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106397592A (zh) * 2015-07-31 2017-02-15 苏州康宁杰瑞生物科技有限公司 针对程序性死亡配体(pd-l1)的单域抗体及其衍生蛋白
CN107216389A (zh) * 2016-03-18 2017-09-29 苏州纳洛迈生物科技有限公司 抗pd-l1纳米抗体及其编码序列和用途
WO2018024237A1 (zh) * 2016-08-04 2018-02-08 信达生物制药(苏州)有限公司 抗pd-l1纳米抗体及其应用
CN107686520A (zh) * 2016-08-04 2018-02-13 信达生物制药(苏州)有限公司 抗pd‑l1纳米抗体及其应用
WO2018133873A1 (zh) * 2017-01-23 2018-07-26 苏州康宁杰瑞生物科技有限公司 Pd-l1结合多肽或化合物

Non-Patent Citations (10)

* Cited by examiner, † Cited by third party
Title
"Fundamental Immunology", 1989, RAVEN PRESS
"NCBI", Database accession no. NM 014143.4
CLARKSON ET AL., NATURE, vol. 352, 1991, pages 624 - 628
FREEMAN ET AL., J. EXP. MED., vol. 192, 2000, pages 1027
HAMERS-CASTERMAN CATARHOUCH TMUYLDERMANS SROBINSON GHAMERS CSONGA EBBENDAHMAN NHAMERS R: "Naturally Occurring Antibodies Devoid of Light Chains", NATURE, vol. 363, no. 6428, 1993, pages 446 - 448, XP002535892, DOI: 10.1038/363446a0
HARMSEN MMDE HAARD HJ: "Properties, Production, and Applications of Camelid Single-domain Antibody Fragments", APPL MICROBIOL BIOTECHNOL, vol. 77, no. 1, 2007, pages 13 - 22
KABAT ET AL.: "Sequences of Proteins of Immunological Interest", vol. 1-3, 1991, NIH PUBLICATION, pages: 91 - 3242
KINDT ET AL.: "Kuby Immunology", 2007, W.H. FREEMAN AND CO., pages: 91
PORTOLANO ET AL., J. IMMUNOL., vol. 150, 1993, pages 880 - 887
See also references of EP4059962A4

Also Published As

Publication number Publication date
JP7738551B2 (ja) 2025-09-12
US20230002494A1 (en) 2023-01-05
EP4059962A1 (en) 2022-09-21
KR20220087488A (ko) 2022-06-24
EP4059962A4 (en) 2023-11-29
JP2023500110A (ja) 2023-01-04

Similar Documents

Publication Publication Date Title
CN111848800B (zh) Pd-l1单结构域抗体及其用途
CN110121510B (zh) 程序性细胞死亡(pd-1)的单结构域抗体
CN108124445B (zh) Ctla4抗体、其药物组合物及其用途
CN110366560B (zh) 抗b7-h4抗体、其抗原结合片段及其医药用途
CN112745391B (zh) Pd-l1结合分子
WO2023193732A1 (zh) 一种抗ccr8抗体或其抗原结合片段
WO2021219048A1 (zh) 一种靶向nkg2a和pd-l1的双特异性抗体及应用
WO2022007543A1 (zh) 一种抗fgl1抗体及其应用
WO2022247804A1 (zh) 抗gprc5d抗体、其制备方法与用途
CN110799546A (zh) 重组双特异性抗体
WO2022042715A1 (zh) 靶向PD-L1和TGFβ的双功能融合蛋白及其制备方法与应用
CN107840885A (zh) Gm‑csf抗体及其用途
CN115197321B (zh) 靶向cd25的抗体及其用途
WO2021143914A1 (zh) 一种激活型抗ox40抗体、生产方法及应用
WO2023232110A1 (zh) 抗人cd24抗体及其应用
US20260028402A1 (en) Anti-cd100 antibody and use thereof
EP4410840A1 (en) Bispecific antibody and application thereof
CN110642947A (zh) 抗人cd147的单克隆抗体、表达载体、细胞株及其应用
JP7738551B2 (ja) Ｐｄ－ｌ１結合分子
WO2023103962A1 (zh) Tnfr2结合分子及其用途
CN115109157A (zh) 抗体或其抗原结合片段，其制备方法及医药用途
CN116234559A (zh) 抗cd22单结构域抗体和治疗性构建体
CN112521499A (zh) 抗cxcl13抗体及其用途
CN114075284B (zh) Cd47结合分子及其用途
WO2024078558A1 (zh) 抗cd100抗体及其用途

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20882932

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2022525333

Country of ref document: JP

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 20227016606

Country of ref document: KR

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2020882932

Country of ref document: EP

Effective date: 20220530