WO2020210231A1

WO2020210231A1 - Compositions and methods for the cry opreservation of immune cells

Info

Publication number: WO2020210231A1
Application number: PCT/US2020/027070
Authority: WO
Inventors: Yosef Refaeli; Brian C. TURNER; Thomas R. PAYNE
Original assignee: Taiga Biotechnologies Inc
Current assignee: Taiga Biotechnologies Inc
Priority date: 2019-04-08
Filing date: 2020-04-07
Publication date: 2020-10-15
Anticipated expiration: 2021-10-08
Also published as: IL287010A; SG11202111081XA; JP2022527117A; US20220142149A1; CN113874033A; US12250943B2; CA3132857A1; KR20210149746A; EP3952909A1; EP3952909A4; AU2020272664A1

Abstract

Provided herein are compositions and methods for the cryopreservation of immune cells, such as peripheral blood mononuclear cells (PBMCs) by pre-treating the cells with a PTD-MYC fusion protein (e.g., an HIV TAT-MYC fusion protein) prior to freezing. Kits for practicing the methods are also provided herein.

Description

COMPOSITIONS AND METHODS FOR THE CRYOPRESERVATION

OF IMMUNE CELLS CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Patent Application No.62/830,950, filed April 8, 2019, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD The present technology relates to compositions and methods for the

cryopreservation of immune cells, such as peripheral blood mononuclear cells (PBMCs) by pre-treating the cells with a PTD-MYC fusion protein (e.g., an HIV TAT-MYC fusion polypeptide) prior to freezing. Kits for use in practicing the methods are also provided herein. BACKGROUND Cryopreservation is a process in which cells are preserved by cooling them to low temperatures. At these low temperatures, biological activity, including the biochemical reactions that would lead to cell death under normal conditions, are effectively stopped. However, if not properly controlled, cryopreservation can lead to cell damage and a decrease in cell viability. Further, after the freeze-thaw process, cells normally need to be cultured to ensure proper recovery. Currently, there is an unmet need for cryopreservation methods that increase cell viability and recovery after the cryopreserved cells have thawed. SUMMARY In one aspect, the present disclosure provides a frozen composition that includes (a) a MYC fusion polypeptide, comprising (i) a protein transduction domain, (ii) a MYC polypeptide sequence; and (b) one or more peripheral blood mononuclear cells (PBMCs) isolated from a donor subject, wherein the composition exhibits increased cell viability compared to control PBMC cells isolated from the subject. In some embodiments, the protein transduction domain sequence is a TAT protein transduction domain sequence. In some embodiments, the protein transduction domain is TAT_[48-57]. In some embodiments, the protein transduction domain is TAT[57-48]. In some embodiments, the MYC fusion polypeptide comprises SEQ ID NO: 1. In some embodiments, the one or more peripheral blood mononuclear cells comprises a T-cell, a B-cell, an NK cell, a monocyte, a granulocyte, a macrophage, or any combination thereof. In some embodiments, the compositions further include a cell suspension medium. In some embodiments, the cell suspension medium comprises CHB media, CS5 media, or CS10 media. In some embodiments, the composition exhibits increased cell recovery when thawed as compared to control PBMCs in the absence of the MYC fusion polypeptide after a freeze-thaw cycle. In some embodiments, the composition exhibits increased expression of CD25 after cell activation as compared to control PBMCs in the absence of the MYC fusion polypeptide after a freeze-thaw cycle. In some embodiments, the present disclosure provides an immune cell bank comprising the frozen composition. In one aspect, the present disclosure provides a method of cryopreserving peripheral blood mononuclear cells (PBMCs) that includes (a) contacting a composition comprising one or more PBMCs isolated from a donor subject with an effective amount of a MYC fusion polypeptide, comprising (i) a protein transduction domain; (ii) a MYC polypeptide sequence; and (b) cooling the PBMCs to a temperature sufficient to freeze the composition. In some embodiments, the protein transduction domain sequence is a TAT protein transduction domain sequence. In some embodiments, the protein transduction domain is TAT[48-57]. In some embodiments, the protein transduction domain is TAT[57-48]. In some embodiments, the MYC fusion polypeptide comprises SEQ ID NO: 1. In some embodiments, the one or more peripheral blood mononuclear cells comprises a T-cell, a B- cell, an NK cell, a monocyte, a granulocyte, or any combination thereof. In some

embodiments, the method further includes suspending the PBMCs in a cell suspension medium. In some embodiments, the cell suspension medium comprises CHB media, CS5 media, or CS10 media. In some embodiments, the composition comprising one or more PBMCs is contacted with the MYC fusion polypeptide at a concentration of about 0.5µg/mL to about 500 µg/mL. In some embodiments, the composition comprising one or more PBMCs is contacted with the MYC fusion polypeptide at a concentration of about 0.5µg/mL to about 10 µg/mL. In some embodiments, the composition comprising one or more PBMCs is contacted with the MYC fusion polypeptide for less than 24 hours prior to step (b). In some

embodiments, the composition comprising one or more PBMCs is contacted with the MYC fusion polypeptide for about 1 hour prior to step (b). In some embodiments, the PBMCs are washed following step (a) and prior to step (b). In some embodiments, the PBMCs are cooled using a controlled-rate cryogenic freezer. In some embodiments, the PBMCs are cooled at a rate of about -1°C per min. In some embodiments, the temperature sufficient to freeze the composition is about -80°C to about -190°C. In some embodiments, the method further includes thawing of the cryopreserved cells, such that the cells exhibit one or more of increased cell viability, increased cell recovery, cell activation, or increased expression of CD25 after cell activation as compared to control PBMCs not contacted with an effective amount of the MYC fusion polypeptide. Also provided herein are method of using cells that have been cryopreserved using a MYC fusion polypeptide. Also provided herein are kits comprising the MYC fusion polypeptides, the MYC fusion polypeptide-modified immune cells, and/or the frozen composition of the present technology of any embodiment described herein and instructions for use. In one aspect, the present disclosure provides an immune cell bank comprising: (a) a MYC fusion polypeptide, comprising (i) a protein transduction domain; (ii) a MYC polypeptide sequence; and (b) one or more peripheral blood mononuclear cells (PBMCs) isolated from a donor subject. BRIEF DESCRIPTION OF THE DRAWINGS FIG.1 illustrates the cell viability of immune cells (e.g., peripheral blood mononuclear cells (PBMC)), following pre-treatment with a PTD-MYC fusion polypeptide (TBX-3400) or vehicle control (PBMC), cryopreservation under various conditions, and thawing. Cells were stained with either 7-aminoactinomycin D (7-AAD) or trypan blue and analyzed via flow cytometry or hemocytometer to determine the extent of viable cells after thawing. Cells were frozen in CHB media, CS5 media, or CS10 media as indicated, and frozen in a CoolCell® container of VIA Freeze™ controlled rate freezer. FIG.2 illustrates the cell recovery (%) of immune cells (PBMC), following pre- treatment with a PTD-MYC fusion polypeptide, cryopreservation under various conditions, and thawing. Cells were frozen in CHB media, CS5 media, or CS10 media as indicated, and frozen in a CoolCell® container. FIG.3 illustrates the relative amounts of cell populations of immune cells (T- cells, B-cell, monocytes, granulocytes, and NK cells) isolated from donor subjects recovered, following pre-treatment with the PTD-MYC fusion polypeptide or vehicle control, cryopreservation under various conditions, and thawing. Cells were frozen in CHB media, CS5 media, or CS10 media as indicated, and frozen in a CoolCell® container of VIA

Freeze™ controlled rate freezer. Cell populations were determined by flow cytometry and immunophenotyping of the various cell populations. FIG.4 illustrates cell activation of control cells and immune cells, expressed as median fluoresce intensity (Median FI) for CD25 expression, following pre-treatment with the PTD-MYC fusion polypeptide or vehicle control, cryopreservation under various conditions, and thawing. Cells were frozen in CHB media, CS5 media, or CS10 media as indicated, and frozen in a CoolCell® container of VIA Freeze™ controlled rate freezer. Cells were activated with either a single stimulatory molecule (CD3) alone, or in combination with a co-stimulatory molecule (CD28).

FIG.5 illustrates cell activation of control cells and immune cells, expressed as %CD25 positive cells, following pre-treatment with the PTD-MYC fusion polypeptide or vehicle control, cryopreservation under various conditions, and thawing. Cells were frozen in CHB media, CS5 media, or CS10 media as indicated, and frozen in a CoolCell® container of VIA Freeze™ controlled rate freezer. Cells were activated with either a single stimulatory molecule (CD3) alone, or in combination with a co-stimulatory molecule (CD28). DETAILED DESCRIPTION The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as single illustrations of individual aspects of the disclosure. All the various embodiments of the present disclosure will not be described herein. Many modifications and variations of the disclosure can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that the present disclosure is not limited to particular uses, methods, reagents, compounds, compositions or biological systems, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group. As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as“up to,”“at least,”“greater than,”“less than,” and the like, include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. I. Definitions The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a",“an”, and“the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term“about” means that a value can vary +/- 20%, +/- 15%, +/- 10% or +/- 5% and remain within the scope of the present disclosure. For example,“a concentration of about 200 IU/mL” encompasses a concentration between 160 IU/mL and 240 IU/mL. As used herein, the term“administration” of an agent to a subject includes any route of introducing or delivering the agent to a subject to perform its intended function. Administration can be carried out by any suitable route, including intravenously,

intramuscularly, intraperitoneally, or subcutaneously. Administration includes self- administration and the administration by another. The term“amino acid” refers to naturally occurring and non-naturally occurring amino acids, as well as amino acid analogs and amino acid mimetics that function in a manner similar to the naturally occurring amino acids. Naturally encoded amino acids are the 20 common amino acids (alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine) and pyrolysine and

selenocysteine. Amino acid analogs refer to agents that have the same basic chemical structure as a naturally occurring amino acid, i.e., an a carbon that is bound to a hydrogen, a carboxyl group, an amino group, and an R group, such as, homoserine, norleucine, methionine sulfoxide, methionine methyl sulfonium. Such analogs have modified R groups (such as, norleucine) or modified peptide backbones, but retain the same basic chemical structure as a naturally occurring amino acid. In some embodiments, amino acids forming a polypeptide are in the D form. In some embodiments, the amino acids forming a polypeptide are in the L form. In some embodiments, a first plurality of amino acids forming a polypeptide are in the D form and a second plurality are in the L form. Amino acids are referred to herein by either their commonly known three letter symbols or by the one-letter symbols recommended by the IUPAC-IUB Biochemical Nomenclature Commission. Nucleotides, likewise, are referred to by their commonly accepted single-letter code. The terms“polypeptide,”“peptide,” and“protein” are used interchangeably herein to refer to a polymer of amino acid residues. The terms apply to naturally occurring amino acid polymers as well as amino acid polymers in which one or more amino acid residues is a non-naturally occurring amino acid, e.g., an amino acid analog. The terms encompass amino acid chains of any length, including full length proteins, wherein the amino acid residues are linked by covalent peptide bonds. As used herein, a“control” is an alternative sample used in an experiment for comparison purpose. A control can be“positive” or“negative.” For example, where the purpose of the experiment is to determine a correlation of the efficacy of a therapeutic agent for the treatment for a particular type of disease, a positive control (a composition known to exhibit the desired therapeutic effect) and a negative control (a subject or a sample that does not receive the therapy or receives a placebo) are typically employed. As used herein, the term“effective amount” or“therapeutically effective amount” refers to a quantity of an agent sufficient to achieve a desired therapeutic effect. In the context of therapeutic applications, the amount of a therapeutic peptide administered to the subject can depend on the type and severity of the infection and on the characteristics of the individual, such as general health, age, sex, body weight and tolerance to drugs. It can also depend on the degree, severity and type of disease. The skilled artisan will be able to determine appropriate dosages depending on these and other factors. As used herein, the term“expression” refers to the process by which polynucleotides are transcribed into mRNA and/or the process by which the transcribed mRNA is subsequently being translated into peptides, polypeptides, or proteins. If the polynucleotide is derived from genomic DNA, expression can include splicing of the mRNA in a eukaryotic cell. The expression level of a gene can be determined by measuring the amount of mRNA or protein in a cell or tissue sample. In one aspect, the expression level of a gene from one sample can be directly compared to the expression level of that gene from a control or reference sample. In another aspect, the expression level of a gene from one sample can be directly compared to the expression level of that gene from the same sample following administration of the compositions disclosed herein. The term“expression” also refers to one or more of the following events: (1) production of an RNA template from a DNA sequence (e.g., by transcription) within a cell; (2) processing of an RNA transcript (e.g., by splicing, editing, 5’ cap formation, and/or 3’ end formation) within a cell; (3) translation of an RNA sequence into a polypeptide or protein within a cell; (4) post-translational modification of a polypeptide or protein within a cell; (5) presentation of a polypeptide or protein on the cell surface; and (6) secretion or presentation or release of a polypeptide or protein from a cell. The term“linker” refers to synthetic sequences (e.g., amino acid sequences) that connect or link two sequences, e.g., that link two polypeptide domains. In some

embodiments, the linker contains 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 of amino acid sequences. As used herein the term immune cell refers to any cell that plays a role in the immune response. Immune cells are of hematopoietic origin, and include lymphocytes, such as B cells and T cells; natural killer cells; myeloid cells, such as monocytes, macrophages, dendritic cells, eosinophils, neutrophils, mast cells, basophils, and granulocytes. The term“lymphocyte” refers to all immature, mature, undifferentiated and differentiated white lymphocyte populations including tissue specific and specialized varieties. It encompasses, by way of non-limiting example, B cells, T cells, NKT cells, and NK cells. In some embodiments, lymphocytes include all B cell lineages including pre-B cells, progenitor B cells, early pro-B cells, late pro-B cells, large pre-B cells, small pre-B cells, immature B cells, mature B cells, plasma B cells, memory B cells, B-1 cells, B-2 cells and anergic AN1/T3 cell populations. As used herein, the term T-cell includes naïve T cells, CD4+ T cells, CD8+ T cells, memory T cells, activated T cells, anergic T cells, tolerant T cells, chimeric T cells, antigen-specific T cells, and regulatory T cells. The term“B cell” or“B cells” refers to, by way of non-limiting example, a pre-B cell, progenitor B cell, early pro-B cell, late pro-B cell, large pre-B cell, small pre-B cell, immature B cell, mature B cell, naïve B cells, plasma B cells, activated B cells, anergic B cells, tolerant B cells, chimeric B cells, antigen-specific B cells, memory B cell, B-1 cell, B-2 cells and anergic AN1/T3 cell populations. In some embodiments, the term B cell includes a B cell that expresses an immunoglobulin heavy chain and/or light chain on its cells surface. In some embodiments, the term B cell includes a B cell that expresses and secretes an immunoglobulin heavy chain and/or light chain. In some embodiments, the term B cell includes a cell that binds an antigen on its cell-surface. In some embodiments disclosed herein, B cells or AN1/T3 cells are utilized in the processes described. In certain

embodiments, such cells are optionally substituted with any animal cell suitable for expressing, capable of expressing (e.g., inducible expression), or capable of being

differentiated into a cell suitable for expressing an antibody including, e.g., a hematopoietic stem cell, a naïve B cell, a B cell, a pre-B cell, a progenitor B cell, an early Pro-B cell, a late pro-B cell, a large pre-B cell, a small pre-B cell, an immature B cell, a mature B cell, a plasma B cell, a memory B cell, a B-1 cell, a B-2 cell, an anergic B cell, or an anergic AN1/T3 cell. As used herein,“peripheral blood mononuclear cells” refers to any peripheral blood cells having a round nucleus, including lymphocytes, such as T cells, B cells, NK cells, monocytes, macrophages and dendritic cells. As used herein "adoptive cell therapeutic composition" refers to any composition comprising cells suitable for adoptive cell transfer. In exemplary embodiments, the adoptive cell therapeutic composition comprises a cell type selected from a group consisting of a tumor infiltrating lymphocyte (TIL), TCR (i.e., heterologous T-cell receptor) modified lymphocytes and CAR (i.e., chimeric antigen receptor) modified lymphocytes. In another embodiment, the adoptive cell therapeutic composition comprises a cell type selected from a group consisting of T-cells, CD8+ cells, CD4+ cells, NK-cells, delta-gamma T-cells, regulatory T-cells and peripheral blood mononuclear cells (PBMC). In another embodiment, TILs, T-cells, CD8+ cells, CD4+ cells, NK-cells, delta-gamma T-cells, regulatory T-cells or peripheral blood mononuclear cells form the adoptive cell therapeutic composition. In one embodiment, the adoptive cell therapeutic composition comprises T cells. In one

embodiment, the adoptive cell therapeutic composition may be a frozen composition comprising one or more immune cells and/or PBMCs isolated from a donor subject which have been contacted with a MYC fusion polypeptide, comprising (i) a protein transduction domain; (ii) a MYC polypeptide sequence. The terms“MYC” and“MYC gene” are synonyms. They refer to a nucleic acid sequence that encodes a MYC polypeptide. A MYC gene comprises a nucleotide sequence of at least 120 nucleotides that is at least 60% to 100% identical or homologous, e.g., at least 60, 65%, 70%, 75%, 80%, 85%, 86%, 87%, 88%, 90%, 91%, 92%, 94%, 95%, 96%, 97%, 98%, or any other percent from about 70% to about 100% identical to sequences of NCBI Accession Number NM—002467. In some embodiments, the MYC gene is a proto- oncogene. In certain instances, a MYC gene is found on chromosome 8, at 8q24.21. In certain instances, a MYC gene begins at 128,816,862 bp from pter and ends at 128,822,856 bp from pter. In certain instances, a MYC gene is about 6 kb. In certain instances, a MYC gene encodes at least eight separate mRNA sequences—5 alternatively spliced variants and 3 unspliced variants. The terms“MYC protein,”“MYC polypeptide,” and“MYC sequence” are synonyms and refer to the polymer of amino acid residues disclosed in NCBI Accession Number UniProtKB/Swiss-Prot:P01106.1 (MYC isoform 1) or NP_002458.2

(UniProtKB/Swiss-Prot:P01106.2; MYC isoform 2), and functional homologs, analogs or fragments thereof. The sequence of or UniProtKB/Swiss-Prot:P01106.1 is:

The sequence of NP_002458.2 (UniProtKB/Swiss-Prot:P01106.2) is:

11) In some embodiments, the MYC polypeptide is a complete MYC polypeptide sequence. In some embodiments, the MYC polypeptide is a partial MYC polypeptide sequence. In some embodiments, the MYC polypeptide comprises at least 400 consecutive amino acids of SEQ ID NO: 2 OR 11. In some embodiments, the MYC polypeptide comprises at least 400 consecutive amino acids of SEQ ID NO: 2 OR 11 and retains at least one MYC activity. In some embodiments, the MYC polypeptide comprises at least 400, at least 410, at least 420, at least 430, or at least 450 consecutive amino acids of SEQ ID NO: 2 OR 11. In some embodiments, the MYC polypeptide comprises at least 400, at least 410, at least 420, at least 430, or at least 450 consecutive amino acids of SEQ ID NO: 2 OR 11 and retains at least one MYC activity. In some embodiments, the MYC polypeptide is c-MYC. In some embodiments, the MYC polypeptide sequence comprises the sequence shown below:

In some embodiments, the MYC polypeptide sequence comprises the sequence shown below:

In some embodiments, a MYC polypeptide comprises an amino acid sequence that is at least 40% to 100% identical, e.g., at least 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 90%, 91%, 92%, 94%, 95%, 96%, 97%, 98%, 99%, or any other percent from about 40% to about 100% identical to the sequence of NCBI Accession Number NP002458.2 or UniProtKB/Swiss-Prot Accession Number

P01106.1. In some embodiments, MYC polypeptide refers to a polymer of 439 amino acids, a MYC polypeptide that has not undergone any post-translational modifications. In some embodiments, MYC polypeptide refers to a polymer of 439 amino acids that has undergone post-translational modifications. In some embodiments, the MYC polypeptide is 48,804 kDa. In some embodiments, the MYC polypeptide contains a basic Helix-Loop-Helix Leucine Zipper (bHLH/LZ) domain. In some embodiments, the bHLH/LZ domain comprises the sequence of:

In some embodiments, the MYC polypeptide is a

transcription factor (e.g., Transcription Factor 64). In some embodiments, the MYC polypeptide contains an E-box DNA binding domain. In some embodiments, the MYC polypeptide binds to a sequence comprising CACGTG. In some embodiments, the MYC polypeptide promotes one or more of cell survival and/or proliferation. In some

embodiments, a MYC polypeptide includes one or more of those described above, and includes one or more post-translational modifications (e.g., acetylation). In some

embodiments, the MYC polypeptides comprise one or more additional amino acid residues at the N-terminus or C-terminus of the polypeptide. In some embodiments, the MYC polypeptides are fusion proteins. In some embodiments, the MYC polypeptides are linked to one or more additional peptides at the N-terminus or C-terminus of the polypeptide. Proteins suitable for use in the methods described herein also includes functional variants, including proteins having between 1 to 15 amino acid changes, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 amino acid substitutions, deletions, or additions, compared to the amino acid sequence of any protein described herein. In other embodiments, the altered amino acid sequence is at least 75% identical, e.g., 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to the amino acid sequence of any protein inhibitor described herein. Such sequence-variant proteins are suitable for the methods described herein as long as the altered amino acid sequence retains sufficient biological activity to be functional in the compositions and methods described herein. Where amino acid substitutions are made, the substitutions can be conservative amino acid substitutions. Among the common, naturally occurring amino acids, for example, a“conservative amino acid substitution” is illustrated by a substitution among amino acids within each of the following groups: (1) glycine, alanine, valine, leucine, and isoleucine, (2) phenylalanine, tyrosine, and tryptophan, (3) serine and threonine, (4) aspartate and glutamate, (5) glutamine and asparagine, and (6) lysine, arginine and histidine. The BLOSUM62 table is an amino acid substitution matrix derived from about 2,000 local multiple alignments of protein sequence segments, representing highly conserved regions of more than 500 groups of related proteins (Henikoff et al. (1992), Proc. Natl Acad. Sci. USA, 89:10915- 10919). Accordingly, the BLOSUM62 substitution frequencies are used to define conservative amino acid substitutions that, in some embodiments, are introduced into the amino acid sequences described or disclosed herein. Although it is possible to design amino acid substitutions based solely upon chemical properties (as discussed above), the language“conservative amino acid substitution” preferably refers to a substitution

represented by a BLOSUM62 value of greater than -1. For example, an amino acid substitution is conservative if the substitution is characterized by a BLOSUM62 value of 0, 1, 2, or 3. According to this system, preferred conservative amino acid substitutions are characterized by a BLOSUM62 value of at least 1 (e.g., 1, 2 or 3), while more preferred conservative amino acid substitutions are characterized by a BLOSUM62 value of at least 2 (e.g., 2 or 3). The phrases“E-box sequence” and“enhancer box sequence” are used interchangeably herein and mean the nucleotide sequence CANNTG, wherein N is any nucleotide. In certain instances, the E-box sequence comprises CACGTG. In certain instances, the basic helix-loop-helix domain of a transcription factor encoded by MYC binds to the E-box sequence. In certain instances, the E-box sequence is located upstream of a gene (e.g., p21, Bc1-2, or ornithine decarboxylase). In certain instances, the MYC polypeptide contains an E-box DNA binding domain. In certain instances, the E-box DNA binding domain comprises the sequence of KRRTHNVLERQRRN (SEQ ID NO: 6). In certain instances, the binding of the transcription factor encoded by MYC to the E-box sequence, allows RNA polymerase to transcribe the gene downstream of the E-box sequence. The term“MYC activity” or“MYC biological activity” or“biologically active MYC” includes one or more of enhancing or inducing cell survival, cell proliferation, and/or antibody production. By way of example and not by way of limitation, MYC activity includes enhancement of expansion of anti-CD3 and anti-CD28 activated T-cells and/or increased proliferation of long-term self-renewing hematopoietic stem cells. MYC activity also includes entry into the nucleus of a cell, binding to a nucleic acid sequence (e.g., binding an E-box sequence), and/or inducing expression of MYC target genes. The terms“patient,”“subject,”“individual,” and the like are used interchangeably herein, and refer to an animal, typically a mammal. In one embodiment, the patient, subject, or individual is a mammal. In one embodiment, the patient, subject or individual is a human. In some embodiments the patient, subject or individual is an animal, such as, but not limited to, domesticated animals, such as equine, bovine, murine, ovine, canine, and feline. The terms“protein transduction domain (PTD)” or“transporter peptide sequence” (also known as cell permeable proteins (CPP) or membrane translocating sequences (MTS)) are used interchangeably herein to refer to small peptides that are able to ferry much larger molecules into cells independent of classical endocytosis. In some embodiments, a nuclear localization signal can be found within the protein transduction domain, which mediates further translocation of the molecules into the cell nucleus. The terms“treating” or“treatment” as used herein covers the treatment of a disease in a subject, such as a human, and includes: (i) inhibiting a disease, i.e., arresting its development; (ii) relieving a disease, i.e., causing regression of the disease; (iii) slowing progression of the disease; and/or (iv) inhibiting, relieving, or slowing progression of one or more symptoms of the disease. With respect to a tumor,“treating” or“treatment” also encompasses regression of a tumor, slowing tumor growth, inhibiting metastasis of a tumor, inhibiting relapse or recurrent cancer and/or maintaining remission. It is also to be appreciated that the various modes of treatment or prevention of medical diseases and conditions as described are intended to mean“substantial,” which includes total but also less than total treatment or prevention, and wherein some biologically or medically relevant result is achieved. The treatment can be a continuous prolonged treatment for a chronic disease or a single, or few time administrations for the treatment of an acute condition. The term“therapeutic” as used herein means a treatment and/or prophylaxis. A therapeutic effect is obtained by suppression, remission, or eradication of a disease state. II. Overview In one aspect, the present disclosure relates to, in part, to the cryopreservation of a composition comprising one or more immune cells (e.g., peripheral blood mononuclear cells (PBMC)) isolated from a donor subject, wherein the one or more immune cells are contacted with an effective amount of a PTD-MYC fusion polypeptide in vitro prior to cooling the composition to a temperature sufficient to freeze the composition. In another aspect, the present disclosure relates to, in part, to the cryopreservation of a composition comprising one or more peripheral blood mononuclear cells (PBMCs) isolated from a donor subject, wherein the one or more PBMCs are contacted with an effective amount of a PTD-MYC fusion polypeptide in vitro prior to cooling the cooling the composition to a temperature sufficient to freeze the composition. The present disclosure is based, at least in part, on the discovery, that contacting one or more immune cells and/or PBMCs isolated from a donor subject with a MYC fusion polypeptide containing a MYC polypeptide and a protein transduction domain (PTD), such as the HIV TAT protein transduction domain, and cooling the treated immune cells and/or PBMCs to a temperature sufficient to freeze the cells significantly increases cell viability and/or cell recovery, as well as significantly increases expression of CD25 after cell activation compared to control immune cells and/or PBMCs not treated with the MYC fusion polypeptide. The examples provided herein demonstrate that immune cells and/or PBMCs isolated from donor subjects which have been contacted with a TAT-MYC fusion protein prior to cryopreservation exhibit one or more of increased cell viability, increased cell recovery, increased cell activation with CD3 and CD28, or increased expression of CD25 upon cell activation when thawed as compared to control PBMCs after a freeze-thaw cycle. In some embodiments, the present disclosure provides a method for

cryopreserving immune cells, the method comprising contacting a composition comprising one or more PBMCs isolated from a donor subject with an effective amount of a MYC fusion polypeptide, comprising (i) a protein transduction domain (PTD); (ii) a MYC polypeptide sequence, and cooling the PBMCs to a temperature sufficient to freeze the composition. In some embodiments, the present disclosure provides a method for

cryopreserving peripheral blood mononuclear cells (PBMCs), the method comprising contacting a composition comprising one or more PBMCs isolated from a donor subject with an effective amount of a MYC fusion polypeptide, comprising (i) a protein transduction domain (PTD); (ii) a MYC polypeptide sequence, and cooling the PBMCs to a temperature sufficient to freeze the composition. In some embodiments, the protein transduction domain sequence is a TAT protein transduction domain sequence. In some embodiments, the MYC polypeptide sequence comprises the amino acid sequence set forth in SEQ ID NO: 2 or 11. In some embodiments, the PTD-MYC fusion polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 1. In some embodiments, the one or more immune cells isolated from a donor subject can include B cells, T cells, natural killer (NK) cells, myeloid cells, or any combination thereof. In some embodiments, the one or more myeloid cells isolated from a donor subject can include monocytes, macrophages, dendritic cells, eosinophils, neutrophils, mast cells, basophils, granulocytes, or any combination thereof. In some embodiments, the one or more B cells isolated from a donor subject can include a pre-B cell, a progenitor B cell, an early pro-B cell, a late pro-B cell, a large pre-B cell, a small pre-B cell, an immature B cell, a mature B cell, a naïve B cell, a plasma B cell, an activated B cell, an anergic B cell, a tolerant B cell, a chimeric B cell, an antigen-specific B cell, a memory B cell, a B-1 cell, a B-2 cell, an anergic AN1/T3 cell population, or a combination of two or more thereof. In some embodiments, the one or more T cells isolated from a donor subject can include naïve T cells, CD4+ T cells, CD8+ T cells, memory T cells, activated T cells, anergic T cells, tolerant T cells, chimeric T cells, and antigen-specific T cells, regulatory T cells, or any combination thereof. In some embodiments, the one or more peripheral blood mononuclear cells can be a T-cell, a B-cell, an NK cell, a monocyte, a granulocyte, or any combination thereof. In some embodiments, the method further comprises suspending the one or more immune cells, including one or more PBMCs, in a cell suspension medium. In some embodiments, the cell suspension medium is suitable for cryopreservation of mammalian cells. In some embodiments, the cell suspension medium is suitable for cryopreservation of immune cells, including PBMCs. In some embodiments, the cell suspension medium comprises CHB media, CS5 media, or CS10 media. In some embodiments, the immune cells are cooled using a controlled-rate cryogenic freezer. In some embodiments, the immune cells are cooled at a rate of about -1°C per min. In some embodiments, the PBMCs are cooled using a controlled-rate cryogenic freezer. In some embodiments, the PBMCs are cooled at a rate of about -1°C per min. In some embodiments, the temperature sufficient to freeze the composition is about -80°C to about -190°C. In some embodiments, the temperature sufficient to freeze the composition is about -80°C, about -82°C, about -84°C, about -86°C, about -88°C, about - 90°C, about -92°C, about -94°C, about -96°C, about -98°C, about -100°C, about -105°C, about -110°C, about -115°C, about -120°C, about -125°C, about -130°C, about -135°C, about -140°C, about -145°C, about -150°C, about -155°C, about -160°C, about -165°C, about - 170°C, about -175°C, about -180°C, about -185°C, about -190°C, or any integer value in between. In some embodiments, the method further comprises thawing of the cryopreserved cells, such that the cells exhibit one or more of increased cell viability, increased cell recovery, or increased expression of CD25 after cell activation as compared to control cells not contacted with an effective amount of the MYC fusion polypeptide. In another aspect, the present disclosure provides for a frozen composition comprising a MYC fusion polypeptide, comprising (i) a protein transduction domain; (ii) a MYC polypeptide sequence, and one or more immune cells isolated from a donor subject, wherein the composition exhibits increased cell viability compared to control immune cells isolated from the subject. In another related aspect, the present disclosure provides for a frozen composition comprising a MYC fusion polypeptide, comprising (i) a protein transduction domain; (ii) a MYC polypeptide sequence, and one or more peripheral blood mononuclear cells (PBMCs) isolated from a donor subject, wherein the composition exhibits increased cell viability compared to control PBMCs isolated from the subject. In some embodiments, the protein transduction domain sequence is a TAT protein transduction domain sequence. In some embodiments, the MYC polypeptide sequence comprises the amino acid sequence set forth in SEQ ID NO: 2 or 11. In some embodiments, the PTD-MYC fusion polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 1. In some embodiments, the one or more immune cells isolated from a donor subject can include B cells, T cells, natural killer (NK) cells, myeloid cells, or any combination thereof. In some embodiments, the one or more myeloid cells isolated from a donor subject can include monocytes, macrophages, dendritic cells, eosinophils, neutrophils, mast cells, basophils, granulocytes, or any combination thereof. In some embodiments, the one or more B cells isolated from a donor subject can include a pre-B cell, a progenitor B cell, an early pro-B cell, a late pro-B cell, a large pre-B cell, a small pre-B cell, an immature B cell, a mature B cell, a naïve B cell, a plasma B cell, an activated B cell, an anergic B cell, a tolerant B cell, a chimeric B cell, an antigen-specific B cell, a memory B cell, a B-1 cell, a B-2 cell, an anergic AN1/T3 cell population, or a combination of two or more thereof. In some embodiments, the one or more T cells isolated from a donor subject can include naïve T cells, CD4+ T cells, CD8+ T cells, memory T cells, activated T cells, anergic T cells, tolerant T cells, chimeric T cells, and antigen-specific T cells, regulatory T cells, or any combination thereof. In some embodiments, the one or more peripheral blood mononuclear cells can be a T-cell, a B-cell, an NK cell, a monocyte, a granulocyte, or any combination thereof. In some embodiments, the composition further comprises a cell suspension medium. In some embodiments, the cell suspension medium comprises CHB media, CS5 media, or CS10 media. In some embodiments, the composition exhibits increased cell recovery when thawed as compared to control PBMCs after a freeze-thaw cycle. In some embodiments, the composition exhibits increased expression of CD25 after cell activation as compared to control PBMCs after a freeze thaw cycle. In some embodiments, the compositions of the present technology can

advantageously increase the utilization of immune cells and/or PBMCs in adoptive cell transfer (ACT). Adoptive cell transfer (ACT) is a form of immunotherapy that involves the transfer of immune cells with antitumor activity into patients. ACT typically involves isolation of lymphocytes with antitumor activity from a donor subject, culturing the lymphocytes in vitro to expand the population, and then infusing the lymphocytes into a patient in need thereof. In some embodiments, the immune cells and/or PBMCs are primary cells isolated from a donor. In some embodiments, the immune cells and/or PBMCs are modified following isolation. For example, in some embodiments, the cells are immune cells (e.g., T cells) modified to expression one or more heterologous receptors or modified receptors (e.g., a chimeric antigen receptor). In some embodiments, the cells are engineered chimeric antigen receptor (CAR) T-cells. In some embodiments, the cells are engineered chimeric antigen receptor (CAR) Treg-cells. In some embodiments, the immune cells and modified immune cells that have been cryopreserved according to the methods provided herein can be used to increase an immune response in a subject. Exemplary uses of these cells include but are not limited to cancer immunotherapy and treatment of pathogenic infections, such as viral, bacterial, or fungal infections. In some embodiments, the immune cells and modified immune cells that have been cryopreserved according to the methods provided herein can be used to decrease an immune response in a subject. Exemplary uses of these cells (e.g., Tregs and modified Treg cells) include but are not limited to treatment of autoimmune and allergic diseases and conditions, such as multiple sclerosis (MS), lupus erythematosus, asthma, autoimmune uveitis, Crohn’s disease, colitis, Graft vs. host disease (GvHD), rheumatoid arthritis, inflammatory bowel disease, diabetes, and organ or tissue transplant rejection.

In some embodiments, the compositions of the present technology can be used for in vitro or in vivo immunological studies. In some embodiments, the compositions of the present technology can be used in methods for creating an immune cell bank for use in immunotherapy and adoptive cell transfer. III. Methods of Obtaining and Preparing Immune Cells and/or PBMCs Prior to Cryopreservation Immune cells and/or peripheral blood mononuclear cells for use in the methods provided herein can be obtained using any suitable method known in the art. In some embodiments, the immune cells are primary immune cells. In some embodiments, the immune cells are lymphocytes, such as T and B cells. In some embodiments, the immune cells are natural killer (NK) cells. In some embodiments, the immune cells are a mixture of lymphocytes and NK cells. In some embodiments, the immune cells are peripheral blood mononuclear cells (PBMCs). In some embodiments, the T cells are removed during surgery of a tumor or a metastatic tumor in a subject. For example, in some embodiments, the T cells are isolated after removal of tumor tissue by biopsy. In some embodiments, the peripheral blood mononuclear cells (PBMCs) can be a T-cell, a B-cell, an NK cell, a monocyte, a granulocyte, or any combination thereof. In some embodiments, the immune cells can be isolated from a sample containing a population of cells, such as a blood, lymph or tissue biopsy sample. Immune cells can be isolated from a population of cells by any means known in the art. In some embodiments, the immune cells can be isolated from a whole blood sample, such as a peripheral blood sample. In some embodiments, immune cells can be isolated from a leukapheresis unit. In some embodiments, peripheral blood mononuclear cells can be isolated from a leukapheresis unit. In some embodiments, the peripheral blood mononuclear cell fraction can be isolated from a whole blood sample via gradient separation with any suitable density gradient media. In some embodiments, for example, the density gradient media used to isolate the peripheral blood mononuclear cell fraction is Ficoll-Paque^® PLUS or Ficoll-Paque^® PREMIUM. In one embodiment, the PBMC fraction is isolated from a whole blood sample via gradient separation with Ficoll-Paque^® PLUS media. In some embodiments, the blood anticoagulant, ethylenediaminetetraacetic acid (EDTA), is employed to prevent coagulation of the blood sample. Accordingly, in some embodiments the methods employ collection vials coated with the EDTA. EDTA acts as a blood anticoagulant via chelation of Ca²⁺ ions in the blood sample responsible for coagulation and clotting. In some embodiments, the red blood cells of the sample are depleted from the sample. In one embodiment, the method comprises obtaining a bulk population of immune cells from a tumor sample by any suitable method known in the art. For example, a bulk population of immune cells can be obtained from a tumor sample by dissociating the tumor sample into a cell suspension from which specific cell populations can be selected. Suitable methods of obtaining a bulk population of immune cells can include, but are not limited to, any one or more of mechanically dissociating (e.g., mincing) the tumor, enzymatically dissociating (e.g., digesting) the tumor, and aspiration (e.g., as with a needle). The population of immune cells obtained from a sample can comprise any suitable type of immune cell including, but not limited to, B cells, T cells, natural killer (NK) cells, myeloid cells, or any combination thereof. In some embodiments, the bulk population of myeloid cells obtained from a sample can include monocytes, macrophages, dendritic cells, eosinophils, neutrophils, mast cells, basophils, granulocytes, or any combination thereof. The population of T cells obtained from a sample can comprise any suitable type of T cell. In some embodiments, the T cells obtained from a sample can comprise naïve T cells, CD4+ T cells, CD8+ T cells, memory T cells, activated T cells, anergic T cells, tolerant T cells, chimeric T cells, and antigen-specific T cells, or any combination thereof. The population of B cells obtained from a sample can comprise any suitable type of B cell. In some embodiments, the B cells obtained from a sample can comprise pre-B cells, progenitor B cells, early pro-B cells, late pro-B cells, large pre-B cells, small pre-B cells, immature B cells, mature B cells, naïve B cells, plasma B cells, activated B cells, anergic B cells, tolerant B cells, chimeric B cells, antigen-specific B cells, memory B cells, B-1 cells, B-2 cells, anergic AN1/T3 cell populations, or a combination of two or more thereof. The population of immune cells obtained from a sample can comprise peripheral blood mononuclear cells (PBMCs). In some embodiments, the PBMCs obtained from a sample can comprise a T-cell, a B-cell, an NK cell, a monocyte, a granulocyte, or any combination thereof. The sample can be obtained from any mammal. Unless stated otherwise, as used herein, the term "mammal" refers to any mammal including, but not limited to, mammals of the order Logomorpha, such as rabbits; the order Carnivora, including Felines (cats) and Canines (dogs); the order Artiodactyla, including Bovines (cows) and Swines (pigs); or of the order Perssodactyla, including Equines (horses). The mammals can be non-human primates, e.g., of the order Primates, Ceboids, or Simoids (monkeys) or of the order Anthropoids (humans and apes). In some embodiments, the mammal can be a mammal of the order Rodentia, such as mice and hamsters. Preferably, the mammal is a non-human primate or a human. An exemplary mammal is a human. In some embodiments, immune cells can be further isolated by positive or negative selection techniques. Enrichment of an immune cell population by negative selection can be accomplished with a combination of antibodies directed to surface markers unique to the negatively selected cells. Cells can be enriched by cell sorting and/or selection via negative magnetic immunoadherence or flow cytometry that uses a cocktail of monoclonal antibodies directed to cell surface markers present on the cells negatively selected. For example, to enrich for CD4+ cells by negative selection, a monoclonal antibody cocktail typically includes antibodies to CD14, CD20, CD11b, CD16, HLA-DR, and CD8. Further, monocyte populations (i.e., CD14+ cells) can be depleted from blood preparations by a variety of methodologies, including, but not limited to anti-CD14 coated beads or columns, or utilization of the phagocytotic activity of these cells to facilitate removal. For isolation of a desired population of cells by positive or negative selection, the concentration of cells and surface (e.g., particles such as beads) can be varied. In certain embodiments, it can be desirable to significantly decrease the volume in which beads and cells are mixed together (i.e., increase the concentration of cells), to ensure maximum contact of cells and beads. For example, in one embodiment, a concentration of 2 billion cells/mL can be used. In one embodiment, a concentration of 1 billion cells/mL is used. In a further embodiment, greater than 100 million cells/mL can be used. In a further embodiment, a concentration of cells of about 10 million cells/mL, about 15 million cells/mL, about 20 million cells/mL, about 25 million cells/mL, about 30 million cells/mL, about 35 million cells/mL, about 40 million cells/mL, about 45 million cells/mL, or about 50 million cells/mL can be used. In yet another embodiment, a concentration of cells from about 75 million cells/mL, about 80 million cells/mL, about 85 million cells/mL, about 90 million cells/mL, about 95 million cells/mL, or about 100 million cells/mL can be used. In further

embodiments, concentrations of about 125 million cells/mL or about 150 million cells/mL can be used. Using high concentrations can result in increased cell yield, cell activation, and cell expansion. Further, use of high cell concentrations allows more efficient capture of cells that can weakly express target antigens of interest, such as CD28-negative T cells, or from samples where there are many tumor cells present (i.e., leukemic blood, tumor tissue, etc.). Such populations of cells can have therapeutic value and therefore would be desirable to obtain. For example, using high concentration of cells allows more efficient selection of CD8+ T cells that normally have weaker CD28 expression. In another related embodiment, it can be desirable to use lower concentrations of cells. By significantly diluting the mixture of the immune cells and surface (e.g., particles such as beads), interactions between the particles and cells is minimized. This selects for cells that express high amounts of desired antigens to be bound to the particles. For example, CD4+ T cells express higher levels of CD28 and are more efficiently captured than CD8+ T cells in dilute concentrations. In some embodiments, the concentration of cells used can be 5×10⁶/mL. In some embodiments, the concentration used can be from about 1×10⁵/mL to 1×10⁶/mL, or any integer value in between. Thus, the concentration used can be from about 1×10⁵/mL, about 1.1×10⁵/mL, about 1.2×10⁵/mL, about 1.3×10⁵/mL, about 1.4×10⁵/mL, about 1.5×10⁵/mL, about 1.6×10⁵/mL, about 1.7×10⁵/mL, about 1.8×10⁵/mL, about

1.9×10⁵/mL, about 2×10⁵/mL, about 2.2×10⁵/mL, about 2.4×10⁵/mL, about 2.6×10⁵/mL, about 2.8×10⁵/mL, about 3×10⁵/mL, about 3.2×10⁵/mL, about 3.4×10⁵/mL, about

3.6×10⁵/mL, about 3.8×10⁵/mL, about 4×10⁵/mL, about 4.2×10⁵/mL, about 4.4×10⁵/mL, about 4.6×10⁵/mL, about 4.8×10⁵/mL, about 5×10⁵/mL, about 5.5×10⁵/mL, about 6×10⁵/mL, about 6.5×10⁵/mL, about 7×10⁵/mL, about 7.5×10⁵/mL, about 8×10⁵/mL, about 8.5×10⁵/mL, about 9×10⁵/mL, about 9.5×10⁵/mL, about 1×10⁶/mL, or any integer value in between. In some embodiments, cells are directly labeled with an epitope-specific reagent for isolation by flow cytometry followed by characterization of cell phenotypes. In some embodiments, immune cells are isolated by contacting the immune cell specific antibodies. In some embodiments, PBMCs are isolated by contacting the PBMC specific antibodies. Sorting of antigen-specific T cells, or generally any cells of the present technology, can be carried out using any of a variety of commercially available cell sorters, including, but not limited to, MoFlo sorter (DakoCytomation, Fort Collins, Colo.), FACSAria™, FACSArray™,

FACSVantage™, BD™ LSR II, and FACSCalibur™ (BD Biosciences, San Jose, Calif.). IV. MYC fusion proteins In some embodiments, the PTD-MYC fusion polypeptide comprises a protein transduction domain (PTD), a MYC polypeptide that promotes one or more of cell survival or proliferation, and optionally a protein tag domain, e.g., one or more amino acid sequences that facilitate purification of the fusion protein. In some embodiments, a cell contacted with MYC polypeptide exhibits increased survival time (e.g., as compared to an identical or similar cell of the same type that was not contacted with MYC), and/or increased

proliferation (e.g., as compared to an identical or similar cell of the same type that was not contacted with MYC). In some embodiments, the fusion polypeptide comprises (a) a protein transduction domain; and (b) a MYC polypeptide sequence. In some embodiments, the fusion polypeptide is a polypeptide of Formula (I): protein transduction domain-MYC polypeptide sequence. In some embodiments, a fusion polypeptide disclosed herein comprises (a) a protein transduction domain; (b) a MYC polypeptide sequence; and (c) one or more molecules that link the protein transduction domain and the MYC polypeptide sequence. In some embodiments, the fusion polypeptide is a polypeptide of Formula (II): protein transduction domain-X-MYC polypeptide sequence, wherein -X- is a molecule that links the protein transduction domain and the MYC

polypeptide sequence. In some embodiments, -X- is at least one amino acid. In some embodiments, a fusion polypeptide disclosed herein comprises (a) a protein transduction domain; (b) a MYC polypeptide sequence; (c) at least two protein tags; and (d) optionally linker(s). In some embodiments, the fusion polypeptide is a polypeptide of Formula (III-VI): protein transduction domain-X-MYC polypeptide sequence-X-protein tag 1-X-protein tag 2

(Formula (III)), or protein transduction domain-MYC polypeptide sequence-X-protein tag 1-X-protein tag 2

(Formula (IV)), or protein transduction domain-MYC polypeptide sequence-protein tag 1-X-protein tag 2 (Formula (V)), or protein transduction domain-MYC polypeptide sequence-protein tag 1-protein tag 2 (Formula (VI)), wherein -X- is a linker. In some embodiments, -X- is one or more amino acids. In some embodiments, a fusion polypeptide disclosed herein comprises (a) a protein transduction domain; (b) a MYC polypeptide sequence; (c) a 6-histidine tag; (d) a V5 epitope tag: and (e) optionally linker(s). In some embodiments, the fusion polypeptide is a polypeptide of Formula (VII-XIV): protein transduction domain-X-MYC polypeptide sequence-X-6-histidine tag-X-V5 epitope tag (Formula (VII)), or protein transduction domain-MYC polypeptide sequence-X-6-histidine tag-X-V5 epitope tag

(Formula (VIII)), or protein transduction domain-MYC polypeptide sequence-6-histidine tag-X-V5 epitope tag

(Formula (IX)), or protein transduction domain-MYC polypeptide sequence-6-histidine tag-V5 epitope tag (Formula (X)), protein transduction domain-X-MYC polypeptide sequence-X-V5 epitope tag-X-6-histidine tag (Formula (XI)), or protein transduction domain-MYC polypeptide sequence-X-V5 epitope tag-X-6-histidine tag

(Formula (XII)), or protein transduction domain-MYC polypeptide sequence-V5 epitope tag-X-6-histidine tag

(Formula (XIII)), or protein transduction domain-MYC polypeptide sequence-V5 epitope tag-6-histidine tag (Formula (XIV)), wherein -X- is a linker. In some embodiments, -X- is one or more amino acids. As noted above, in some embodiments, the MYC fusion protein comprises one or more linker sequences. The linker sequences can be employed to link the protein transduction domain, MYC polypeptide sequence, V5 epitope tag and/or 6-histidine tag of the fusion protein. In some embodiments, the linker comprises one or more amino acids. In some embodiments, the amino acid sequence of the linker comprises KGELNSKLE. In some embodiments, the linker comprises the amino acid sequence of RTG. Protein Transduction Domain (PTD) In some embodiments, the MYC fusion protein includes a protein transduction domain. Peptide transport provides an alternative for delivery of small molecules, proteins, or nucleic acids across the cell membrane to an intracellular compartment of a cell. One non- limiting example and well-characterized protein transduction domain (PTD) is a TAT-derived peptide. Frankel et al. (see, e.g., U.S. Pat. No.5,804,604, U.S. Pat. No.5,747,641, U.S. Pat. No.5,674,980, U.S. Pat. No.5,670,617, and U.S. Pat. No.5,652,122) demonstrated transport of a cargo protein (b-galactosidase or horseradish peroxidase) into a cell by conjugating a peptide containing amino acids 48–57 of TAT to the cargo protein. In some embodiments, TAT comprises an amino acid sequence of MRKKRRQRRR (SEQ ID NO: 7). Another non-limiting example of a PTD is penetratin. Penetratin can transport hydrophilic macromolecules across the cell membrane (Derossi et al., Trends Cell Biol., 8:84–87 (1998) incorporated herein by reference in its entirety). Penetratin is a 16 amino acid peptide that corresponds to amino acids 43–58 of the homeodomain of Antennapedia, a Drosophila transcription factor which is internalized by cells in culture. Yet another non-limiting example of a PTD is VP22. VP22, a tegument protein from Herpes simplex virus type 1 (HSV-1), has the ability to transport proteins and nucleic acids across a cell membrane (Elliot et al., Cell 88:223–233, 1997, incorporated herein by reference in its entirety). Residues 267–300 of VP22 are necessary but cannot be sufficient for transport. Because the region responsible for transport function has not been identified, the entire VP22 protein is commonly used to transport cargo proteins and nucleic acids across the cell membrane (Schwarze et al., Trends Pharmacol Sci, 21:45–48, 2000). In some embodiments, the PTD-MYC fusion polypeptide includes a protein transduction domain. By way of example, but not by way of limitation, in some

embodiments, the protein transduction domain comprises the protein transduction domain of one or more of TAT, penetratin, VP22, vpr, EPTD, R9, R15, VP16, and Antennapedia. In some embodiments, the protein transduction domain comprises the protein transduction domain of one or more of TAT, penetratin, VP22, vpr, and EPTD. In some embodiments, the protein transduction domain comprises the protein transduction domain of at least one of TAT, penetratin, VP22, vpr, EPTD, R9, R15, VP16, and Antennapedia. In some

embodiments, the protein transduction domain comprises a synthetic protein transduction domain (e.g., polyarginine or PTD-5). In particular embodiments, the protein transduction domain comprises a TAT protein transduction domain. In some embodiments, the protein transduction domain is covalently linked to the MYC polypeptide. In some embodiments, the protein transduction domain is linked to the MYC polypeptide via a peptide bond. In some embodiments, the protein transduction domain is linked to the MYC polypeptide via a linker sequence. In some embodiments, the linker comprises a short amino acid sequence. By way of example, but not by way of limitation, in some embodiments, the linker sequence is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acids in length. The MYC fusion protein of the present technology can be arranged in any desired order. For example, in some embodiments, the MYC fusion protein can be arranged in order of a) the protein transduction domain linked in frame to the MYC polypeptide, b) the MYC polypeptide linked in frame to the V5 domain, and c) the V5 domain linked in frame to the 6- histidine epitope tag. In some embodiments, the MYC fusion protein has an order of components of a) the MYC polypeptide linked in frame to the protein transduction domain, b) the protein transduction domain linked in frame to the V5 domain, and c) the V5 domain linked in frame to the 6-histidine epitope tag. In some embodiments, one or more additional amino acid sequences or linkers can be included between each of the sequences. In some embodiments, additional amino acids can be included at the start and/or end of the

polypeptide sequences. In some embodiments, the protein transduction domain is a TAT protein transduction domain. In some embodiments, the protein transduction domain is TAT_[48-57]. In some embodiments, the protein transduction domain is TAT[57-48]. Protein Tag Domains In some embodiments, the MYC fusion protein comprises a protein tag domain that comprises one or more amino acid sequences that facilitate purification of the fusion protein. In some embodiments, the protein tag domain comprises one or more of a polyhistidine tag, and an epitope tag. By way of example, but not by way of limitation, exemplary tags include one or more of a V5, a histidine-tag (e.g., a 6-histidine tag), HA (hemagglutinin) tags, FLAG tag, CBP (calmodulin binding peptide), CYD (covalent yet dissociable NorpD peptide), Strepll, or HPC (heavy chain of protein C). In some

embodiments, the protein tag domain comprises about 10 to about 20 amino acids in length. In some embodiments, the protein tag domain comprises 2 amino acids to 40 amino acids in length, for example 6-20 amino acids in length. In some embodiments, the protein tag domain comprises 2 amino acids, 3 amino acids, 4 amino acids, 5 amino acids, 6 amino acids, 7 amino acids, 8 amino acids, 9 amino acids, 10 amino acids, 11 amino acids, 12 amino acids, 13 amino acids, 14 amino acids, 15 amino acids, 16 amino acids, 17 amino acids, 18 amino acids, 19 amino acids, 20 amino acids, 21 amino acids, 22 amino acids, 23 amino acids, 24 amino acids, 25 amino acids, 26 amino acids, 27 amino acids, 28 amino acids, 29 amino acids, 30 amino acids, 31 amino acids, 32 amino acids, 33 amino acids, 34 amino acids, 35 amino acids, 36 amino acids, 37 amino acids, 38 amino acids, 39 amino acids, or 40 amino acids. In some embodiments, two of the above listed tags (for example, V5 and the HIS-tag) are used together to form the protein tag domain. In some embodiments, the histidine tag is a 6-histidine tag. In some embodiments, the histidine tag comprises the sequence HHHHHH (SEQ ID NO:8). In some embodiments, the fusion polypeptide disclosed herein comprises a V5 epitope tag. In some embodiments, the V5 tag comprises the amino acid sequence of: GKPIPNPLLGLDST (SEQ ID NO:9). In some embodiments, the V5 tag comprises the amino acid sequence of IPNPLLGLD (SEQ ID NO:10). The protein tags can be added to the fusion protein disclosed herein by any suitable method. By way of example, but not by way of limitation, in some embodiments, a TAT-MYC polypeptide sequence is cloned into an expression vector encoding one or more protein tags, e.g., a polyHis-tag and/or a V5 tag. In some embodiments, a polyhistidine tag and/or a V5 tag is added by PCR (i.e., the PCR primers comprise a polyhistidine sequence and/ or V5 sequence). Construction of PTD-MYC fusion polypeptides PTD-MYC fusion polypeptides (e.g., TAT-MYC fusion polypeptide) disclosed herein can be constructed by methods well known in the art. By way of example, but not by way of limitation, a nucleotide sequence encoding a TAT-MYC fusion polypeptide can be generated by PCR. In some embodiments, a forward primer for a human MYC sequence comprises an in frame N-terminal 9-amino-acid sequence of the TAT protein transduction domain (e.g., RKKRRQRRR). In some embodiments, a reverse primer for a human MYC sequence is designed to remove the stop codon. In some embodiments, the PCR product is cloned into any suitable expression vector. In some embodiments, the expression vector comprises a polyhistidine tag and a V5 tag. In some embodiments, a fusion polypeptide disclosed herein comprises (a) TAT, and (b) c-MYC. In some embodiments, a fusion polypeptide disclosed herein comprises (a) TAT[48-57], and (b) c-MYC. In some embodiments, a fusion polypeptide disclosed herein comprises (a) TAT_[57-48], and (b) c-MYC. In some embodiments, a fusion polypeptide disclosed herein comprises (a) TAT, (b) c-MYC, (c) linker(s), (d) V5 tag, and (e) 6-histidine tag. In some embodiments, a fusion polypeptide disclosed herein comprises (a) TAT[48-57], (b) c-MYC, (c) linker(s), (d) V5 tag, and (e) 6-histidine tag. In some embodiments, a fusion polypeptide disclosed herein comprises (a) TAT[57-48], (b) c-MYC, (c) linker(s), (d) V5 tag, and (e) 6-histidine tag. In some embodiments, the PTD-MYC fusion polypeptide comprises SEQ ID NO: 1; in some embodiments, the PTD-MYC fusion polypeptide is SEQ ID NO: 1.

The fusion protein can be modified during or after synthesis to include one or more functional groups. By way of example but not by way of limitation, the protein can be modified to include one or more of an acetyl, phosphate, acetate, amide, alkyl, and/or methyl group. This list is not intended to be exhaustive, and is exemplary only. In some

embodiments, the protein includes at least one acetyl group. A PTD-MYC fusion polypeptide can be generated by any suitable method known the art, e.g. by recombinant protein expression in a cell, such as a bacterial cell, an insect cell, or mammalian cell. In some embodiments, a PTD-MYC fusion polypeptide is recombinantly produced by microbial fermentation. In some embodiments microbial fermentation is performed in a fermentation volume of from about 1 to about 10,000 liters, for example, a fermentation volume of about 10 to about 1000 liters. The fermentation can utilize any suitable microbial host cell and culture medium. In exemplary embodiments, E. coli is utilized as the microbial host cell. In alternative embodiments, other microorganisms can be used, e.g., S. cerevisiae, P. pastoris, Lactobacilli, Bacilli and Aspergilli. In an exemplary embodiment the microbial host cell is BL-21 Star^TM E. coli strain (Invitrogen). In an exemplary embodiment the microbial host cell is BLR DE3 E. coli. strain. In some embodiments the host cells are modified to provide tRNAs for rare codons, which are employed to overcome host microbial cell codon bias to improve translation of the expressed proteins. In exemplary embodiments, the host cells (e.g., E. coli) transformed with a plasmid, such as pRARE (CamR), which express tRNAs for AGG, AGA, AUA, CUA, CCC, GGA codons. Additional, suitable plasmids or constructs for providing tRNAs for particular codons are known in the art and can be employed in the methods provided. Integrative or self-replicative vectors can be used for the purpose of introducing the PTD-MYC fusion polypeptide expression cassette into a host cell of choice. In an expression cassette, the coding sequence for the PTD-MYC fusion polypeptide is operably linked to promoter, such as an inducible promoter. Inducible promoters are promoters that initiate increased levels of transcription from DNA under their control in response to some change in culture conditions, e.g., the presence or absence of a nutrient or a change in temperature. In some embodiments, the nucleic acid encoding the PTD-MYC fusion polypeptide is codon optimized for bacterial expression. Exemplary promoters that are recognized by a variety of potential host cells are well known. These promoters can be operably linked to PTD-MYC fusion polypeptide- encoding DNA by removing the promoter from the source DNA, if present, by restriction enzyme digestion and inserting the isolated promoter sequence into the vector. Promoters suitable for use with microbial hosts include, but are not limited to, the b-lactamase and lactose promoter systems (Chang et al. (1978) Nature, 275:617-624; Goeddel et al. (1979) Nature, 281: 544), alkaline phosphatase, a tryptophan (trp) promoter system (Goeddel (1980) Nucleic Acids Res.8: 4057; EP 36,776), and hybrid promoters such as the tac promoter (deBoer et al. (1983) Proc. Natl. Acad. Sci. USA 80: 21-25). Any promoter for suitable for expression by the selected host cell can be used. Nucleotide sequences for suitable are published, thereby enabling a skilled worker operably to ligate them to DNA encoding PTD- MYC fusion polypeptide (see, e.g., Siebenlist et al. (1980) Cell 20: 269) using linkers or adaptors to supply any required restriction sites. In exemplary embodiments, promoters for use in bacterial systems can contain a Shine-Dalgarno (S.D.) sequence operably linked to the coding sequence. In some embodiments, the inducible promoter is the lacZ promoter, which is induced with Isopropyl b-D-1-thiogalactopyranoside (IPTG), as is well-known in the art. Promoters and expression cassettes can also be synthesized de novo using well known techniques for synthesizing DNA sequences of interest. In an exemplary embodiment, the expression vector for expression of the PTD-MYC fusion polypeptides herein is pET101/D- Topo (Invitrogen). For expression of the PTD-MYC fusion polypeptides, the microbial host containing the expression vector encoding the PTD-MYC fusion polypeptide is typically grown to high density in a fermentation reactor. In some embodiments, the reactor has controlled feeds for glucose. In some embodiments, a fermenter inoculum is first cultured in medium supplemented with antibiotics (e.g., overnight culture). The fermenter inoculum is then used to inoculate the fermenter culture for expression of the protein. At an OD600 of at least about 15, usually at least about 20, at least 25, at least about 30 or higher, of the fermenter culture, expression of the recombinant protein is induced. In exemplary embodiments, where the inducible promoter is the lacZ promoter, IPTG is added to the fermentation medium to induce expression of the PTD-MYC fusion polypeptide. Generally, the IPTG is added to the fermenter culture at an OD600 which represents logarithmic growth phase. In certain embodiments of the methods provided, induced protein expression is maintained for around about 2 to around about 5 hours post induction, and can be from around about 2 to around about 3 hours post-induction. Longer periods of induction can be undesirable due to degradation of the recombinant protein. The temperature of the reaction mixture during induction is preferably from about 28°C to about 37°C, usually from about 30°C to about 37°C. In particular embodiments, induction is at about 37°C. The PTD-MYC fusion polypeptide is typically expressed as cytosolic inclusion bodies in microbial cells. To harvest inclusion bodies, a cell pellet is collected by

centrifugation of the fermentation culture following induction, frozen at -70°C or below, thawed and resuspended in disruption buffer. The cells are lysed by conventional methods, e.g., sonication, homogenization, etc. The lysate is then resuspended in solubilization buffer, usually in the presence of urea at a concentration effective to solubilize proteins, e.g., from around about 5M, 6M, 7M, 8M, 9M or greater. Resuspension can require mechanically breaking apart the pellet and stirring to achieve homogeneity. In some embodiments, the cell pellet is directly resuspended in urea buffer and mixed until homogenous. In some embodiments, the resuspension/solubilization buffer is 8M Urea, 50 mM Phosphate pH 7.5 and the suspension is passed through a homogenizer. In some embodiments, the homogenized suspension is sulfonylated. For example, in some embodiments, the homogenized suspension is adjusted to include 200 mM Sodium Sulfite and 10 mM Sodium Tetrathionate. The solution is then mixed at room temperature until homogeneous. The mixed lysate is then mixed for an additional period of time to complete the sulfonylation (e.g., at 2-8°C for ³ 12 hours). The sulfonylated lysate was then centrifuged for an hour. The supernatant containing the sulfonylated PTD-MYC fusion polypeptides is then collected by centrifugation and the cell pellet discarded. The supernatant is then passed through a filter, e.g., 0.22 mm membrane filter to clarify the lysate. The solubilized protein is then purified. Purification methods can include affinity chromatography, reverse phase chromatography, gel exclusion chromatography, and the like. In some embodiments, affinity chromatography is used. For example, the protein is provided with an epitope tag or histidine 6 tag for convenient purification. In the present methods, exemplary PTD-MYC fusion polypeptide comprise histidine 6 tag for purification using Ni affinity chromatography using Ni- resin. In exemplary embodiments, the Ni- resin column is equilibrated in a buffer containing urea. In some embodiments, the equilibration buffer is 6M Urea, 50 mM

Phosphate, 500 mM NaCl, and 10% Glycerol solution. The sulfonylated and clarified supernatant comprising the PTD-MYC fusion polypeptide is then loaded onto the Ni- resin column. The column is then washed with a wash buffer, e.g., 6M Urea, 50mM Phosphate, 10% Glycerol, 500 mM NaCl, pH 7.5. The column was then washed with sequential wash buffers with decreasing salt concentration. For example, exemplary subsequent washed can include 6M Urea, 50mM Phosphate, 10% Glycerol, and 2M NaCl, pH 7.5, followed another wash of 6M Urea, 50mM Phosphate, 10% Glycerol, 50mM NaCl, and 30mM Imidazole, pH 7.5. Following sequential application of the wash buffers the PTD-MYC fusion polypeptide is eluted from the column by addition of elution buffer, e.g., 6M Urea, 50mM Phosphate, 10% Glycerol, and 50mM NaCl, pH 7.5 with a gradient from 100 to 300 mM Imidazole, and collecting fractions. The protein containing fractions to be pooled are then filtered through a 0.22 mm membrane. Assessment of protein yield can be measured using any suitable method, e.g., spectrophotometry at UV wavelength 280. In some embodiments, one or more additional purification methods can be employed to further purify the isolated PTD-MYC fusion polypeptides. In exemplary embodiments, the pooled fractions from the Ni-Sepharose chromatography step are further purified by anion exchange chromatography using a Q-Sepharose resin. In some

embodiments, the pool is prepared for loading onto the Q-Sepharose column by diluting the samples to the conductivity of the Q Sepharose buffer (17.52 +/-1 mS/cm) with the second wash buffer (e.g., 6M Urea, 50mM Phosphate, 10% Glycerol, 2M NaCl, pH 7.5) from the Ni Sepharose chromatography step. The diluted pool is then loaded onto the Q-Sepharose column, followed by two chase steps using a chase buffer (e.g., 6M Urea, 50mM Phosphate, 300mM NaCl, and 10% Glycerol), with further sequential applications of the chase buffer until the UV trace reaches baseline, indicating that the protein has eluted from the column. V. Methods of Cryopreservation As provided previously, the present disclosure is directed to methods for the cryopreservation of immune cells, where the method comprises (a) contacting a composition comprising one or more immune cells isolated from a donor subject with an effective amount of a MYC fusion polypeptide, comprising (i) a protein transduction domain; (ii) a MYC polypeptide sequence, and cooling the immune cells to a temperature sufficient to freeze the composition. Exemplary MYC fusion polypeptides are provided herein. In some embodiments, the protein transduction domain sequence is a TAT protein transduction domain sequence. In some embodiments, the MYC fusion polypeptide comprises SEQ ID NO: 1. In some embodiments, the immune cells are peripheral blood mononuclear cells (PBMCs). Accordingly, the present disclosure is also directed to methods for the

cryopreservation of PBMCs, where the method comprises (a) contacting a composition comprising one or more PBMCs isolated from a donor subject with an effective amount of a MYC fusion polypeptide, comprising (i) a protein transduction domain; (ii) a MYC polypeptide sequence, and cooling the PBMCs to a temperature sufficient to freeze the composition. In some embodiments, the protein transduction domain sequence is a TAT protein transduction domain sequence. In some embodiments, the MYC fusion polypeptide comprises SEQ ID NO: 1. In exemplary embodiments of the methods, a whole blood sample of about 30 mL to about 470 mL is isolated from a donor subject. Thus, a whole blood sample of about 30 mL, about 32 mL, about 34 mL, about 36 mL, about 38 mL, about 40 mL, about 42 mL, about 44 mL, about 46 mL, about 48 mL, about 50 mL, about 55 mL, about 60 mL, about 65 mL, about 70 mL, about 75 mL, about 80 mL, about 85 mL, about 90 mL, about 95 mL, about 100 mL, about 110 mL, about 120 mL, about 130 mL, about 140 mL, about 150 mL, about 160 mL, about 170 mL, about 180 mL, about 190 mL, about 200 mL, about 220 mL, about 240 mL, about 260 mL, about 280 mL, about 300 mL, about 320 mL, about 340 mL, about 360 mL, about 380 mL, about 400 mL, about 420 mL, about 440 mL, about 460 mL, about 470 mL, or any integer value in between, can be isolated from a donor subject. In some embodiments, the whole blood sample isolated from a donor subject is then immediately treated with an anticoagulant, such as EDTA (about 1.5 % w/v). In some embodiments, the isolated whole blood sample is then allowed to incubate for a period of time (e.g., about 1-24 hours) at about 20°C to allow the sample to separate the immune cells and/or PBMCs from other components of the whole blood sample (i.e., red blood cells, platelets, plasma, etc.). In some embodiments, separation is carried out using a density-gradient solution (DGS). In some embodiments, a SEPAX-100 cell processing system (Biosafe America Inc., Houston, TX) is employed. The separated cells can be washed one or more times during the cell separation process to remove residual blood components. In some embodiments, the cells are washed using a 2.5% (w/v) HSA (Human Serum Albumin) solution in saline, and then resuspended in the same wash solution to provide a cell suspension. In some embodiments, samples of the cell suspension can be taken prior to treatment with the PTD-MYC fusion polypeptide (negative controls). In some embodiments, the remaining cells in the suspension can then be treated with the PTD-MYC fusion polypeptide, for example, at a concentration of about 0.5µg/mL to about 500 µg/mL. In some embodiments, treated and non-treated (negative controls) samples can then be incubated at room temperature for an appropriate time, for example, about 1 hour. In some embodiments, the immune cells (e.g., PBMCs) are contacted with an effective amount of a PTD-MYC fusion polypeptide for a period of time sufficient to be taken up by the cells prior to freezing. In some embodiments, the immune cells are contacted with an effective amount of a PTD-MYC for less than about 24 hours, less than about 23 hours, less than about 22 hours, less than about 21 hours, less than about 20 hours, less than about 19 hours, less than about 18 hours, less than about 17 hours, less than about 16 hours, less than about 15 hours, less than about 14 hours, less than about 13 hours, less than about 12 hours, less than about 11 hours, less than about 10 hours, less than about 9 hours, less than about 8 hours, less than about 7 hours, less than about 6 hours, less than about 5 hours, less than about 4 hours, less than about 3 hours, less than about 2 hours, less than about 1 hour, less than about 45 minutes, less than about 30 minutes, less than about 15 minutes, or less than about 10 minutes. In some embodiments, the immune cells (e.g., PBMCs) are contacted with an effective amount of a PTD-MYC fusion polypeptide for about 1 hour. In some embodiments, the immune cells (e.g., PBMCs) are contacted with a PTD- MYC fusion polypeptide at a concentration of about 0.5µg/mL to about 500 µg/mL. In some embodiments, that can be combined with any of the preceding embodiments, the cells are contacted with a PTD-MYC fusion polypeptide at a concentration of at least 0.5µg/mL, at least 0.6µg/mL, at least 0.7µg/mL, at least 0.8µg/mL, at least 0.9µg/mL, at least 1µg/mL, at least 2µg/mL, at least 3µg/mL, at least 4µg/mL, at least 5µg/mL, at least 6µg/mL, at least 7µg/mL, at least 8µg/mL, at least 9µg/mL, at least 10µg/mL, at least 15µg/mL, at least 20µg/mL, at least 25µg/mL, at least 30µg/mL, at least 35µg/mL, at least 40µg/mL, at least 45µg/mL, at least 50µg/mL, at least 55µg/mL, at least 60µg/mL, at least 65µg/mL, at least 70µg/mL, at least 75µg/mL, at least 80µg/mL, at least 85µg/mL, at least 90µg/mL, at least 95µg/mL, at least 100µg/mL, at least 110µg/mL, at least 120µg/mL, at least 130µg/mL, at least 140µg/mL, at least 150µg/mL, at least 160µg/mL, at least 170µg/mL, at least

180µg/mL, at least 190µg/mL, at least 200µg/mL, at least 220µg/mL, at least 240µg/mL, at least 260µg/mL, at least 280µg/mL, at least 300µg/mL, at least 320µg/mL, at least

340µg/mL, at least 360µg/mL, at least 380µg/mL, at least 400µg/mL, at least 420µg/mL, at least 440µg/mL, at least 460µg/mL, at least 480µg/mL, at least 500µg/mL, or any integer value in between. Following incubation with the TAT-MYC polypeptide, the treated immune cells and/or treated PBMCs (TBX-3400) can then be re-washed (e.g., on the SEPAX-100) one or more times, to remove excess PTD-MYC from the cells with a wash solution (e.g., a 2.5% (w/v) HSA solution). Following the final wash step, the treated cells can be resuspended, for example, at a concentration of about 0.5x10⁶ cells/mL to about 1x10⁸ cells/mL. In some embodiments, the treated cells can be resuspended at a concentration of about 0.5x10⁶ cells/mL, about 0.6x10⁶ cells/mL, about 0.7x10⁶ cells/mL, about 0.8x10⁶ cells/mL, about 0.9x10⁶ cells/mL, about 1x10⁶ cells/mL, about 1.1x10⁶ cells/mL, about 1.2x10⁶ cells/mL, about 1.3x10⁶ cells/mL, about 1.4x10⁶ cells/mL, about 1.5x10⁶ cells/mL, about 1.6x10⁶ cells/mL, about 1.7x10⁶ cells/mL, about 1.8x10⁶ cells/mL, about 1.9x10⁶ cells/mL, about 2x10⁶ cells/mL, about 2.2x10⁶ cells/mL, about 2.4x10⁶ cells/mL, about 2.6x10⁶ cells/mL, about 2.8x10⁶ cells/mL, about 3x10⁶ cells/mL, about 3.2x10⁶ cells/mL, about 3.4x10⁶ cells/mL, about 3.6x10⁶ cells/mL, about 3.8x10⁶ cells/mL, about 4x10⁶ cells/mL, about 4.2x10⁶ cells/mL, about 4.4x10⁶ cells/mL, about 4.6x10⁶ cells/mL, about 4.8x10⁶ cells/mL, about 5x10⁶ cells/mL, about 5.5x10⁶ cells/mL, about 6x10⁶ cells/mL, about 6.5x10⁶ cells/mL, about 7x10⁶ cells/mL, about 7.5x10⁶ cells/mL, about 8x10⁶ cells/mL, about 8.5x10⁶ cells/mL, about 9x10⁶ cells/mL, about 9.5x10⁶ cells/mL, about 1x10⁷ cells/mL, about 1.1x10⁷ cells/mL, about 1.2x10⁷ cells/mL, about 1.3x10⁷ cells/mL, about 1.4x10⁷ cells/mL, about 1.5x10⁷ cells/mL, about 1.6x10⁷ cells/mL, about 1.7x10⁷ cells/mL, about 1.8x10⁷ cells/mL, about 1.9x10⁷ cells/mL, about 2x10⁷ cells/mL, about 2.2x10⁷ cells/mL, about 2.4x10⁷ cells/mL, about 2.6x10⁷ cells/mL, about 2.8x10⁷ cells/mL, about 3x10⁷ cells/mL, about 3.2x10⁷ cells/mL, about 3.4x10⁷ cells/mL, about 3.6x10⁷ cells/mL, about 3.8x10⁷ cells/mL, about 4x10⁷ cells/mL, about 4.2x10⁷ cells/mL, about 4.4x10⁷ cells/mL, about 4.6x10⁷ cells/mL, about 4.8x10⁷ cells/mL, about 5x10⁷ cells/mL, about 5.5x10⁷ cells/mL, about 6x10⁷ cells/mL, about 6.5x10⁷ cells/mL, about 7x10⁷ cells/mL, about 7.5x10⁷ cells/mL, about 8x10⁷ cells/mL, about 8.5x10⁷ cells/mL, about 9x10⁷ cells/mL, about 9.5x10⁷ cells/mL, about 1x10⁸ cells/mL, or any integer value in between. Following cell treatment with PTD-MYC, the treated cells can be centrifuged and resuspended, at a pre-determined concentration (cells/mL). In some embodiments, the cells are resuspended in a suitable freezing medium. In some embodiments, the cell suspension medium is selected from among CHB media, CS10 media, or CS5 media. CHB media is a cell suspension media which contains 50% (v/v) fetal bovine serum (FBS), 40% (v/v) RPMI cell culture media, and 10% (v/v) dimethyl sulfoxide (DMSO). CS10 media (BioLife

Solutions, Inc., Bothell, WA) is a cell culture media comprising 10% (v/v) DMSO and is essentially free of animal components or serum. CS5 (BioLife Solutions, Inc.) media is a cell culture media comprising 5% (v/v) DMSO and is essentially free of animal components or serum. The resuspended PTD-MYC treated cells can then be vialed and cryogenically frozen. The composition comprising the PTD-MYC treated cells can be cryogenically frozen by any method known in the art. For example, composition comprising the PTD-MYC treated cells can be cryogenically frozen by a method that provides controlled cooling to the desired temperature. In some embodiments, composition comprising the PTD-MYC treated immune cells (e.g., PBMC) are cooled using a controlled-rate cryogenic freezer. In some embodiments, composition comprising the PTD-MYC treated immune cells (e.g., PBMC) are cooled at a rate of about -1°C per min. In some embodiments, the temperature sufficient to freeze the composition is about -80°C to about -190°C. In some embodiments, the temperature sufficient to freeze the composition is about -80°C, about -82°C, about -84°C, about -86°C, about -88°C, about - 90°C, about -92°C, about -94°C, about -96°C, about -98°C, about -100°C, about -105°C, about -110°C, about -115°C, about -120°C, about -125°C, about -130°C, about -135°C, about -140°C, about -145°C, about -150°C, about -155°C, about -160°C, about -165°C, about - 170°C, about -175°C, about -180°C, about -185°C, about -190°C, or any integer value in between. In some embodiments, the PTD-MYC treated cells are cryogenically frozen via loading into a CoolCell^® cell freezing container (BioCision), followed by incubation at - 80°C. The CoolCell^® provide a cooling rate of about -1°C per minute. In some embodiments, the TBX-3400 and control cells are cryogenically frozen via loading into a VIA Freeze™ system (GE Healthcare Life Sciences, Pittsburgh, PA) with a cooling rate of -1°C per minute until the temperature reached -80°C. Following cryopreservation of the cell samples, the samples can be transferred to a liquid nitrogen freezer at -190°C, where the samples can be stored in the vapor phase of the liquid nitrogen. In some embodiments of the methods provided herein, the one or more immune cells (e.g., PBMCs) isolated from a donor subject can be immediately treated with an anticoagulant following isolation. In some embodiments, the one or more immune cells (e.g., PBMCs) isolated from a donor subject can be immediately treated with the PTD-MYC fusion polypeptide following isolation. In other embodiments, the one or more immune cells isolated from a donor subject can be stored in a suitable buffer prior to treatment with the PTD-MYC fusion polypeptide. In some embodiments, the one or more immune cells isolated from a donor subject can be immediately treated with the PTD-MYC fusion polypeptide following isolation and the treated cells are stored in a suitable buffer prior to freezing. In some embodiments, the anticoagulant can be one or more of

ethylenediaminetetraacetic acid (EDTA), heparin, warfarin, rivaroxaban, dabigatran, apixaban, edoxaban, enoxaparin, fondaparinux, acid citrate dextrose (ACD-A), sodium citrate, oxalate, citrate phosphate double dextrose (CP2D), or any combination thereof. In some embodiments, the one or more peripheral blood mononuclear cells (PBMC) can be a T-cell, a B-cell, an NK cell, a monocyte, a granulocyte, macrophage, or any combination thereof. In some embodiments, the one or more immune cells isolated from a donor subject can include B cells, T cells, natural killer (NK) cells, myeloid cells, or any combination thereof. In some embodiments, the one or more myeloid cells isolated from a donor subject can include monocytes, macrophages, dendritic cells, eosinophils, neutrophils, mast cells, basophils, granulocytes, or any combination thereof. In some embodiments, the one or more B cells isolated from a donor subject can include a pre-B cell, a progenitor B cell, an early pro-B cell, a late pro-B cell, a large pre-B cell, a small pre-B cell, an immature B cell, a mature B cell, a naïve B cell, a plasma B cell, an activated B cell, an anergic B cell, a tolerant B cell, a chimeric B cell, an antigen-specific B cell, a memory B cell, a B-1 cell, a B-2 cell, an anergic AN1/T3 cell population, or a combination of two or more thereof. In some embodiments, the one or more T cells isolated from a donor subject can include naïve T cells, CD4+ T cells, CD8+ T cells, memory T cells, activated T cells, anergic T cells, tolerant T cells, chimeric T cells, and antigen-specific T cells, regulatory T cells, or any combination thereof. In some embodiments, the method further comprises thawing of the cryopreserved cells, such that the cells exhibit one or more of increased cell viability, increased cell recovery, or increased expression of CD25 after cell activation as compared to control PBMCs not contacted with an effective amount of the MYC fusion polypeptide. In some embodiments, after thawing of the cryopreserved cells the immune cells can be assessed for viability and or ability to be activated. For example, lymphocytes can be assessed for activation by stimulation or activation by a single agent that induce immune cells activation. In another embodiment, after thawing of the cryopreserved cells the immune cells can be stimulated or activated with two agents, one that induces a primary signal and a second that is a co-stimulatory signal. Ligands useful for stimulating a single signal or stimulating a primary signal and an accessory molecule that stimulates a second signal can be used in soluble form. Ligands can be attached to the surface of a cell, to an Engineered Multivalent Signaling Platform (EMSP), or immobilized on a surface. In a one embodiment both primary and secondary agents are co-immobilized on a surface, for example a bead or a cell. In some embodiments, the molecule providing the activation signal by a single agent can be a CD3 ligand. In some embodiments, the molecule providing the primary activation signal can be a CD3 ligand, and the co-stimulatory molecule can be a CD28 ligand. In some embodiments, the method further comprises thawing of the cryopreserved cells, such that the cells exhibit one or more of increased cell viability, increased cell recovery, cell activation, or increased expression of CD25 after cell activation as compared to control PBMCs not contacted with an effective amount of the MYC fusion polypeptide. VI. Immune Cell Banking In some embodiments, the present disclosure is directed to methods for establishing immune cell banks. As demonstrated by Example 6 (Tables 2 and 3), PBMCs contacted by the MYC fusion polypeptides of present technology were successfully cryopreserved without loss of viability. This facilitates the establishment of cell banks of immune cells that can be stored and used at a later time, thereby offering logistical advantages for immunotherapies, and enabling immune cells to be readily available for adoptive cell transfer. VII. Kits Kits according to this embodiment can comprise a carrier means, such as a box, carton, tube, having in close confinement therein one or more containers, such as vials, tubes, ampoules, bottles, syringes, or bags. The kits can also comprise associated instructions for using the MYC-fusion polypeptides, MYC-fusion polypeptide-modified immune cells, and/or the frozen composition of the present technology. In some embodiments, the kit comprises an effective amount of an adoptive cell therapy, such as MYC-fusion polypeptide-modified immune cells. In some embodiments, the kit comprises one for more reagents for the detection of the administered MYC-fusion polypeptides and/or MYC-fusion polypeptide- modified immune cells. EXAMPLES The present technology is further illustrated by the following Examples, which should not be construed as limiting in any way. The examples herein are provided to illustrate advantages of the present technology and to further assist a person of ordinary skill in the art with preparing or using the compositions and systems of the present technology. The examples should in no way be construed as limiting the scope of the present technology, as defined by the appended claims. The examples can include or incorporate any of the variations, aspects, or embodiments of the present technology described above. The variations, aspects, or embodiments described above can also further each include or incorporate the variations of any or all other variations, aspects or embodiments of the present technology. Example 1: Materials and Methods Activation of Peripheral Blood Mononuclear Cells (PBMCs). A 24-well plate was coated with a solution of an anti-CD3e antibody (500 µL, 5 µg/mL; BD Biosciences) in sterile DPBS. For control wells, only 500 µL of DPBS was added. The plates were allowed to incubated overnight at 4°C prior to removing the solutions. Each well was then washed twice with 2 mL of sterile DPBS. Cells were then resuspended in complete RPMI medium (cRPMI) at a concentration of 2x10⁶ cells/mL, and subsequently washed with 1 mL of DPBS. Next, 1.0 mL of the cell suspension was added to each well according to the plate layout. Next, a solution of an anti-CD28 antibody (100 µL, 200 µg/mL; BD Biosciences) was prepared in cRPMI and serially diluted 10-fold to make two stock solutions of the CD28 antibody in cRPMI (20 µg/mL, and 2 µg/mL). Next, 10 µL of the appropriate CD28 antibody solution or DPBS (controls or singly activated cells) was added to the designated wells. Assay plates were then incubated at 37°C, 5% CO2 for 48 or 72 hours, followed by staining with the appropriate antibodies (anti-human CD25-PE, BD Biosciences) for visualization of activated by FACS analysis. Example 2: Improved Cryopreservation of Immune Cells and/or PBMCs After

Treatment with TAT-MYC In this example, a whole blood sample (450-470 mL) was isolated from a human donor subject and mixed with the blood anticoagulant, ethylenediaminetetraacetic acid (EDTA, about 1.5 % w/v), After allowing the cells to incubate at least 24 hours at about 20°C, the whole blood sample is then separated into peripheral blood mononuclear cells (PBMCs) and waste (i.e., red blood cells, platelets, plasma, etc.) using a density-gradient solution (DGS) on a SEPAX-100 cell processing system (Biosafe America Inc., Houston, TX). The PBMCs were washed two times during the cell separation process with a 2.5% (w/v) HSA (Human Serum Albumin) solution in saline. Following the wash steps, the PBMCs were resuspended in the 2.5% (w/v) HSA solution at a concentration of 13.6x10⁶ cells/mL to provide a cell suspension. Following the cell separation process, samples of the PBMCs were taken from the cell suspension prior to treatment (negative control), and the remaining cells in the cell suspension were treated with TAT-MYC fusion protein (25 µg/mL) and incubated at room temperature for 1 hour. The treated PBMCs (called TBX-3400) were then re-washed on the SEPAX-100, and excess TAT-MYC is washed off of the cells with the 2.5% (w/v) HSA solution. Following the final wash step, the TBX-3400 were resuspended in in the 2.5% (w/v) HSA solution at a concentration of 2.7x10⁶ cells/mL. Following cell treatment with TAT-MYC, the control PBMCs and the TBX-3400 were centrifuged and resuspended, at a pre-determined concentration (cells/mL), in one of three cell suspension mediums: CHB media, CS10 media, or CS5 media. CHB media is a cell suspension media which contains 50% (v/v) fetal bovine serum (FBS), 40% (v/v) RPMI cell culture media, and 10% (v/v) dimethyl sulfoxide (DMSO). CS10 media (BioLife Solutions, Inc.) is a cell culture media comprising 10% (v/v) DMSO and is essentially free of animal components or serum. CS5 media (BioLife Solutions, Inc.) is a cell culture media comprising 5% (v/v) DMSO and is essentially free of animal components or serum. The resuspended TBX-3400 and control PBMCs were then vialed and cryogenically frozen via one of two methods. In the first method, the cryogenic vials (containing the control PBMCs or TBX-3400) were loaded into a CoolCell^® cell freezing container (BioCision), followed by incubation at -80°C. The samples were incubated for 24 hours in the CoolCell^® cell freezing containers at -80°C (which provided a cooling rate of - 1°C/min). After freezing, the samples were then stored in the vapor phase of a liquid nitrogen freezer at -190°C. In the second method, the cryogenic vials (containing the control PBMCs or TBX-3400) were loaded into a VIA Freeze™ system (GE Healthcare Life Sciences, Pittsburgh, PA) with a cooling rate of -1°C/min until the temperature reached -80°C. After freezing, the samples were then stored in the vapor phase of a liquid nitrogen freezer at - 190°C. Control PBMC samples were suspended in each of the three media (CHB media, CS10 media, and/or CS5 media) and then split into separate samples to be frozen via the CoolCell^® cell freezing container or the VIA Freeze™ system. TBX-3400 samples were suspended in each of the three media (CHB media, CS10 media, and/or CS5 media) and then frozen via the CoolCell^® cell freezing container. Example 3: Improved Cell Viability and Cell Recovery After Thawing Cryopreserved PBMCs Treated with TAT-MYC In this example, the cell viability and recovery of control PBMCs and the TBX- 3400 were determined by flow cytometry. Briefly, cell counts were performed before cryopreservation and after thawing the cryopreserved cells. Briefly, frozen and/or cryopreserved cells were quickly thawed in a water bath (37°C) or a Via Thaw system (GE Healthcare Life Sciences). The thawed cell suspension was then transferred into a 50 mL conical tube, and the cell suspension was diluted drop-wise with cRPMI (for osmotic balancing), then diluted slowly up to about 10 mL to about 30 mL with cRPMI. The cell suspension was then centrifuged at 160-400 RCF for 10 minutes at 20°C, and resuspended in 10 mL of cRPMI. Cells were then incubated at 37°C, 5% CO2 overnight. To determine cell viability, a sample of the cell suspension containing 1x10⁶ cells/mL was transferred to a microcentrifuge tube and pelleted at 2,000 rpm for 5 minutes. The cell pellet was then resuspended in DPBS and 5µL of 7-aminoactinomycin D (7-AAD) were added. Following a 10 minute incubation in the dark at room temperature, the samples were analyzed via flow cytometry to determine the cell viability after cryopreservation. FIG. 1 demonstrates that the TBX-3400 exhibits a significant increase in cell viability post- cryopreservation following treatment with the PTD-MYC fusion polypeptide. To determine cell recovery, cell counts were performed with a hemocytometer. Briefly, a sample of the cell suspension containing 1x10⁶ cells/mL was lysed with RBC lysis buffer and allowed to incubate at room temperature. The cell suspensions were then mixed with trypan blue stain (1:1) and the cells were counted with the hemocytometer. FIG.2 illustrates that the TBX-3400 which were cryopreserved in the CS5 cell suspension medium and frozen using the CoolCell^® cell freezing container exhibit about a 95% recovery of viable cells, while TBX-3400 cryopreserved in CHB or CS5 cell suspension mediums demonstrated about 45% and 40% recovery, respectively. Accordingly, these results demonstrate that the compositions and methods disclosed herein exhibit increased cell viability and/or increased cell recovery as compared to control PBMCs not contacted with an effective amount of the MYC fusion polypeptide. Example 4: Determination of Cell Populations of Isolated PBMCs after Treatment with TAT-MYC In this example, the populations of isolated peripheral blood mononuclear cells (PBMCs) were determined by flow cytometry. Briefly, a cell suspension containing at least 3x10⁶ cells/mL was centrifuged for 5 min at 1,600 rpm to pellet the cells. The cells were then washed 1x with DPBS and resuspended at a concentration of 1x10⁶ cells/mL. Next, 1 µL/mL of freshly prepared LIVE/DEAD Fixable Near-IR Dead Cell Dye was added to the cell suspension. The dye was prepared by adding 50 µL of DMSO to one vial of LIVE/DEAD Fixable Near-IR Dead Cell Dye (ThermoFisher Scientific, Waltham, MA). The cells were then incubated in the dark at room temperature for about 30 minutes. Following 1x wash with DPBS, the cells were resuspended to a final concentration of 1x10⁶ cells/mL in 1% BSA or DPBS. Further, the cell suspension was transferred to three staining tubes and stained with the appropriate antibodies as indicated in Table 1. The staining tubes were then allowed to incubate in the dark for 20 minutes at room temperature. Following incubation, 0.1 mL of an Optilyse B (Beckman Coulter) staining solution were added to each tube, followed by. Following incubation, the samples were analyzed via flow cytometry to determine the populations of PBMCs (FIG.3). Table 1. Staining with antibodies.

Example 5: Improved Cell Activation After Thawing Cryopreserved Immune Cells and/or PBMCs Treated with TAT-MYC In this example, the cell activation of control PBMCs and the TBX-3400 were determined by flow cytometry with either one activation agent or two co-activating agents. Briefly, following the thawing of cryopreserved control PBMCs or TBX-3400 cells, the cells were suspended in cRPMI at a concentration of 2x10⁶ cells/mL, and 1 mL of the cell suspension was added to a 24 well plate coated with an anti-CD3 antibody. Further, 10 µL of a CD28 antibody (20 µg/mL) in cRPMI were added to the designated wells, followed by incubation at 37°C, 5% CO₂ for 72 hours. Following incubation, the samples were mixed thoroughly and stained with a CD25-FITC antibody. Following incubation, the samples were transferred to a FACS tube and analyzed via flow cytometry to determine the cell activation with CD3 alone, or in combination with CD28 (FIG.4). Further, the fraction of CD25 positive cells was determined after cell activation of control PBMCs and the TBX-3400 by flow cytometry with either one activation agent or two co-activating agents. Following cell activation with CD3 and/or CD28, the samples were mixed thoroughly and stained with CD25-FITC (Beckman Coulter). FIG.5 illustrates the fraction of CD25 positive cells as determined by flow cytometry after cell activation of control PBMCs and the TBX-3400 which have been previously cryogenically frozen and subsequently thawed. Accordingly, these results demonstrate that the compositions and methods disclosed herein exhibit increased cell activation and/or increased expression of CD25 after cell activation as compared to control PBMCs not contacted with an effective amount of the MYC fusion polypeptide. Example 6: Stability of PBMCs Treated with TAT-MYC In this example, the stability of TBX-3400 was determined by flow cytometry. Total nucleated cell (TNC) counts and viability were measured pre-freeze/pre- cryopreservation and post-thaw for five different PBMC batches stored at either £ -70℃ or £ -150℃ for storage times ranging from 24 hours (24h) to 42 days (42d). Briefly, frozen and/or cryopreserved cells were quickly thawed in a water bath (37°C) or a Via Thaw system (GE Healthcare Life Sciences). The thawed cell suspension was then transferred into a 50 mL conical tube, and the cell suspension was diluted drop-wise with cRPMI (for osmotic balancing), then diluted slowly up to about 10 mL to about 30 mL with cRPMI. The cell suspension was then centrifuged at 160-400 RCF for 10 minutes at 20°C, and resuspended in 10 mL of cRPMI. Cells were then incubated at 37°C, 5% CO₂ overnight. To determine cell viability, a sample of the cell suspension containing 1x10⁶ cells/mL was transferred to a microcentrifuge tube and pelleted at 2,000 rpm for 5 minutes. The cell pellet was then resuspended in DPBS and 5µL of 7-aminoactinomycin D (7-AAD) were added. Following a 10 minute incubation in the dark at room temperature, the samples were analyzed via flow cytometry to determine the cell viability after cryopreservation. Cell counts were performed with a hemocytometer. Briefly, a sample of the cell suspension containing 1x10⁶ cells/mL was lysed with RBC lysis buffer and allowed to incubate at room temperature. The cell suspensions were then mixed with trypan blue stain (1:1) and the cells were counted with the hemocytometer. As shown in Table 2, the MYC fusion polypeptide of the present technology is effective as a cryoprotectant for long-term storage of PBMCs, and, as shown in Table 3, the MYC fusion polypeptide is effective in maintaining the post-thaw stability of PBMCs at ambient temperature. The duration of storage had no effect on the recoveries of TNCs or TNC viability (Table 2). Table 2. Cryopreserved TBX-3400 Stability.

Table 3. Cryopreserved TBX-3400 Stability– Post-Thaw Stability at Ambient Temperature

Accordingly, these results demonstrate that the compositions disclosed herein are useful in methods for long-term storage of immune cells and in methods for immune cell banking.

Claims

WHAT IS CLAIMED IS: 1. A frozen composition comprising:

(a) a MYC fusion polypeptide, comprising (i) a protein transduction domain; (ii) a MYC polypeptide sequence; and

(b) one or more peripheral blood mononuclear cells (PBMCs) isolated from a donor subject;

wherein the composition exhibits increased cell viability compared to control PBMC cells isolated from the subject.

2. The frozen composition of claim 1, wherein the protein transduction domain sequence is a TAT protein transduction domain sequence.

3. The frozen composition of claim 1 or claim 2, wherein the MYC fusion polypeptide comprises SEQ ID NO: 1.

4. The frozen composition of any one of claims 1-3, wherein the one or more peripheral blood mononuclear cells comprises a T-cell, a B-cell, an NK cell, a monocyte, a granulocyte, a macrophage, or any combination thereof.

5. The frozen composition of any one of claims 1-4, further comprising a cell suspension medium.

6. The frozen composition of claim 5, wherein the cell suspension medium comprises CHB media, CS5 media, or CS10 media.

7. The frozen composition of any one of claims 1-6, wherein the composition exhibits increased cell recovery when thawed as compared to control PBMCs in the absence of the MYC fusion polypeptide after a freeze-thaw cycle.

8. The frozen composition of any one of claims 1-7, wherein the composition exhibits increased expression of CD25 after cell activation as compared to control PBMCs in the absence of the MYC fusion polypeptide after a freeze-thaw cycle.

9. A method of cryopreserving peripheral blood mononuclear cells (PBMCs), comprising:

(a) contacting a composition comprising one or more PBMCs isolated from a donor subject with an effective amount of a MYC fusion polypeptide, comprising (i) a protein transduction domain; (ii) a MYC polypeptide sequence; and

(b) cooling the PBMCs to a temperature sufficient to freeze the composition.

10. The method of claim 9, wherein the protein transduction domain sequence is a TAT protein transduction domain sequence.

11. The method of claim 9 or claim 10, wherein the MYC fusion polypeptide comprises SEQ ID NO: 1.

12. The method of any one of claims 9-11, wherein the one or more peripheral blood mononuclear cells comprises a T-cell, a B-cell, an NK cell, a monocyte, a

granulocyte, or any combination thereof.

13. The method of any one of claims 9-12, further comprising suspending the PBMCs in a cell suspension medium.

14. The method of claim 13, wherein the cell suspension medium comprises CHB media, CS5 media, or CS10 media.

15. The method of any one of claims 9-14, wherein the composition comprising one or more PBMCs is contacted with the MYC fusion polypeptide at a concentration of about 0.5µg/mL to about 500 µg/mL.

16. The method of any one of claims 9-14, wherein the composition comprising one or more PBMCs is contacted with the MYC fusion polypeptide at a concentration of about 0.5µg/mL to about 10 µg/mL.

17. The method of any one of claims 9-16, wherein the composition comprising one or more PBMCs is contacted with the MYC fusion polypeptide for less than 24 hours prior to step (b). 51

18. The method of any one of claims 9-16, wherein the composition comprising one or more PBMCs is contacted with the MYC fusion polypeptide for about 1 hour prior to step (b).

19. The method of any one of claims 9-18, wherein the PBMCs are washed following step (a) and prior to step (b).

20. The method of any one of claims 9-19, wherein the PBMCs are cooled using a

controlled-rate cryogenic freezer.

21. The method of any one of claims 9-20, wherein the PBMCs are cooled at a rate of about -1°C per min.

22. The method of any one of claims 9-21, wherein the temperature sufficient to freeze the composition is about -80°C to about -190°C.

23. The method of any one of claims 9-22, further comprising thawing of the

cryopreserved cells, such that the cells exhibit one or more of increased cell viability, increased cell recovery, cell activation, or increased expression of CD25 after cell activation as compared to control PBMCs not contacted with an effective amount of the MYC fusion polypeptide.

24. An immune cell bank comprising:

(b) one or more peripheral blood mononuclear cells (PBMCs) isolated from a donor subject.

25. An immune cell bank comprising the frozen composition of any one of claims 1-8.

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