T Cells That Respond To Patient Neoepitopes
20230236172 · 2023-07-27
Assignee
Inventors
Cpc classification
A61K39/00
HUMAN NECESSITIES
C12N2710/16122
CHEMISTRY; METALLURGY
C12N2710/16134
CHEMISTRY; METALLURGY
International classification
Abstract
Compositions and methods are presented that allow for detection and prediction of an immune response in a subject that is selected to receive or that has received a vaccine. In selected embodiments, whole blood is used as starting material to obtain both dendritic cells and T cells, and synthetic or recombinant polypeptide(s) are used that include an antigen of the vaccine. The dendritic cells are then exposed to the synthetic or recombinant polypeptide(s), and thusly exposed dendritic cells are combined with the T cells to generate antigen reactive T cells. For detection or quantification, the antigen reactive T cells are expanded in vitro prior to ELISPOT or FACS analysis. Advantageously, such systems and methods are especially suitable for ascertaining an immune response against cancer antigens following vaccination with an anti-cancer vaccine.
Claims
1. A method of ascertaining an immune response against an antigen in a subject previously exposed to the antigen, comprising: generating dendritic cells from peripheral blood of the subject, and exposing the dendritic cells to an antigen-containing composition to generate antigen presenting dendritic cells; isolating T cells from peripheral blood of the subject, and contacting the isolated T cells with the antigen presenting dendritic cells; exposing the isolated T cells and the antigen presenting dendritic cells to a cytokine-containing composition to expand antigen-reactive T cells; and detecting the expanded antigen-reactive T cells.
2. The method of claim 1 wherein the subject previously exposed to the antigen is a subject that was previously exposed to a vaccine containing the antigen.
3. The method of claim 2 wherein the vaccine containing the antigen is a recombinant viral vaccine, a recombinant yeast vaccine, and/or a recombinant bacterial vaccine, and wherein the antigen is a patient and tumor specific neoantigen.
4. The method of claim 1, wherein the dendritic cells are generated from monocytes in the peripheral blood.
5. The method of claim 1, wherein the antigen in the antigen-containing composition is a patient and tumor specific neoantigen.
6. The method of claim 1, wherein the antigen in the antigen-containing composition is a full-length protein that contains a neoantigen.
7. The method of claim 1, wherein the antigen-containing composition is a recombinant antigen-containing composition.
8. The method of claim 1, wherein the antigen-containing composition comprises a polytope containing a plurality of distinct antigens or an antigen pool derived from a full-length protein.
9. The method of claim 1, wherein the cytokine-containing composition comprises IL7, IL15, and IL21, or wherein the cytokine-containing composition comprises an IL7/N803/IL21 TxM.
10. The method of claim 1, wherein detecting the expanded antigen-reactive T cells comprises an ELISPOT assay or a FACS assay.
11. The method of claim 1, further comprising a step of administering the expanded antigen-reactive T cells to the subject.
12. A method of predicting a likely immune response against an antigen in a subject selected to receive a vaccine containing the antigen, comprising: generating dendritic cells from peripheral blood of the subject, and exposing the dendritic cells to an antigen-containing composition to generate antigen presenting dendritic cells; isolating T cells from peripheral blood of the subject, and contacting the isolated T cells with the antigen presenting dendritic cells; exposing the isolated T cells and the antigen presenting dendritic cells to a cytokine-containing composition to expand antigen-reactive T cells; quantifying the expanded antigen-reactive T cells; and identifying the subject as a likely immune responder when the quantified expanded antigen-reactive T cells exceed a predetermined threshold quantity.
13. The method of claim 12 wherein the vaccine containing the antigen is a recombinant viral vaccine, a recombinant yeast vaccine, and/or a recombinant bacterial vaccine, and wherein the antigen is a patient and tumor specific neoantigen.
14. The method of claim 12, wherein the dendritic cells are generated from monocytes in the peripheral blood.
15. The method of claim 12, wherein the antigen in the antigen-containing composition is a patient and tumor specific neoantigen.
16. The method of claim 12, wherein the antigen in the antigen-containing composition is included in the vaccine.
17. The method of claim 12, wherein the vaccine comprises a plurality of antigens and wherein the antigen-containing composition comprises a plurality of antigens as an antigen pool or as a polytope, and wherein the plurality of antigens in the vaccine are encoded or present as a polytope.
18. The method of claim 1, wherein the cytokine-containing composition comprises IL7, IL15, and IL21, or wherein the cytokine-containing composition comprises an IL7/N803/IL21 TxM.
19. The method of claim 1, wherein quantifying the expanded antigen-reactive T cells comprises an ELISPOT assay or a FACS assay.
20. The method of claim 1, wherein the predetermined threshold quantity is presence of the expanded antigen-reactive T cells at an abundance of at least 1.0% within an expansion culture.
Description
BRIEF DESCRIPTION OF THE DRAWING
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DETAILED DESCRIPTION
[0029] The inventor has now discovered that successful generation of antigen-reactive T cells in a subject in response to immune therapy can be detected from whole blood in a conceptually simple and effective manner. More particularly, and based on the previously known antigens in the vaccine, an in vitro assay can be performed that uses monocyte derived dendritic cells of the subject that are exposed to the antigen or antigens (e.g., as an antigen pool or polytope), and the so generated antigen presenting dendritic cells are then contacted with T cells of the same subject to generate antigen-reactive T cells that are subsequently expanded using a specific cytokine-containing composition to obtain expanded antigen-reactive T cells for detection and/or quantification. As will be readily appreciated, presence of antigen-reactive T cells will be indicative of an immune response, and especially a therapeutically effective immune response where the quantity of expanded antigen-reactive T cells exceeds a predetermined threshold. Advantageously, detection and/or quantification can be performed using routine methods and equipment. Therefore, it should be recognized that the successful generation of antigen-reactive T cells in a subject in response to immune therapy can be verified (or even predicted) within only days from the subject receiving immune therapy. Consequently, and viewed from a different perspective, contemplated compositions and methods will significantly reduce the time spent between administration of a cancer vaccine and determination of its efficacy in a specific patient.
[0030] As will be readily appreciated, the nature of the immune therapy may vary considerably and will generally include direct or indirect administration of one or more disease related antigens. In preferred embodiments, the antigen is a cancer associated (e.g., MUC-1, CEA, etc.) or a cancer specific (e.g., PSA, PSMA, BRCA1, etc.) antigen, and most preferably a patient and tumor specific neoantigen. Thus, identification of suitable antigens may include a literature review, and more typically omics sequencing (e.g., whole genome sequencing, exon sequencing, RNA-seq, protein mass spectroscopy, etc.). In further preferred aspects, the neoantigens will be confirmed to be expressed in the tumor, and expressed neoantigens may be further filtered to those having a minimal binding affinity (e.g., equal or less than 500 nM, or equal or less than 200 nM, or equal or less than 100 nM) to the subjects HLA type. There are various manners of calculating minimal binding affinity and typical examples include NetMHC4.0, NetMHCpan, PSSNetMHCpan, MHCflurry, etc.
[0031] In still further contemplated aspects, suitable antigens in the cancer vaccine will be a plurality of antigens, typically arranged in a polytope in which neoantigens are sequentially arranged with interspersed (flexible) linker domains, typically having three to fifteen amino acids in length. For example, contemplated vaccine compositions especially include recombinant bacteria (e.g., E. coli, and especially E. coli engineered to lack LPS expression), viruses (e.g., Ad5, and especially Ad5[E1.sup.−Eb2.sup.−]), and/or yeast (e.g., Saccharomyces) that include a recombinant nucleic acid that encodes the antigen or polytope. Of course, it should be recognized that the subject may further receive additional therapeutic agents to stimulate an immune response such as immune stimulating cytokines (e.g., IL15, N803, etc.), checkpoint inhibitors (e.g., targeting CTLA4, PD-1, PD-L1, etc.), and cell based therapies such as T cells and/or NK cells (preferably genetically modified to express a chimeric antigen receptor or other tumor targeting entity).
[0032] Most typically, with respect to dendritic cells and T cells it is preferred that these cells are generated/obtained from peripheral blood. In most cases, PBMCs are obtained from the peripheral using standard methods well known in the art such as Ficoll density gradient centrifugation to obtain a buffy coat or leukapheresis. While dendritic cells may be isolated from PBMC, it is generally preferred that the dendritic cells are derived from monocytes in the PBMC (typically using anti-CD14 antibodies as is well known in the art) to so allow for relatively large quantities and relatively pure dendritic cell populations. Preparation of such monocyte derived dendritic cells is well known in the art (see e.g., J Vis Exp 2016) and will in most cases include a selected cytokine mixture including IL4 and GM-CSF. However, it should also be appreciated that the dendritic cells and/or T cells may also be from a heterologous source, and especially contemplated heterologous sources include HLA matched donors (e.g., with an HLA match to at least 4 digits or at least 6 digits for at least two HLA types (HLA-A, HLA-B, HLA-C, HLA-DR, HLA-DQ, HLA-DP)). In still further contemplated aspects, the dendritic cells and/or the T cells will be fresh cells, however, in some instances such cells may be previously frozen, particularly where the subject has a low count of dendritic cells and/or T cells due to chemotherapy.
[0033] It is still further contemplated that the blood draw may be performed prior to the patient receiving the immune therapy where prediction of an immune response is desired. On the other hand, where the patient has already received the anti-cancer vaccine, the blood draw may be performed between 1 and 7 days, or between 7 and 14 days, or between 14-28 days after first administration of the vaccine. Of course, it should be noted that more than a single blood draw and subsequent analysis is contemplated to allow for monitoring a dynamic immune response (e.g., where individual tests are used to monitor distinct neoantigens to identify antigen spread or to monitor strength of immune response over time to identify optimum response time and then switch to new and distinct vaccine).
[0034] Once blood is drawn and dendritic cells are generated, the dendritic cells can be contacted with the antigen or antigens in numerous manners. Among other options, the dendritic cells may be exposed to one or more individual purified antigens, to a at least partially purified polytope containing at least two antigens (typically separated by a linker peptide), or to crude extracts from cells expressing the antigen or polytope. In still further contemplated aspects, the antigen may also be prepared from an in vitro transcription/translation reaction, and so prepared antigens may be used directly in the transcription/translation mix or be further purified. Upon suitable exposure time, typically between 2-6 hours, or between 6-12 hours, or between 12-24 hours (and in some cases even longer), T cells will be added to the pulsed dendritic cells. Most typically, the T cells will be present relative to the dendritic cells at a ratio of about 10:1, or 7:1, or 5:1, or 3:1, or 1:1, or 1:3, or 1:5, or 1:7, or 1:10. Where desired, the exposure of the T cells to the primed dendritic cells may further include one or more immune stimulating cytokines.
[0035] Regardless of the specific exposure, so activated T cells are then expanded (after optional isolation using a Ficoll gradient) in an expansion medium that contains a cytokine composition to preferentially stimulate cell division of activated T cells. Most typically, the cytokine composition will comprise IL7, IL15, and IL21, or an IL7/N803/IL21 TxM. Expansion will be performed over a period of about 7-20 days, typically for less than two weeks with media change every 2-5 days (e.g., 3-4 days).
[0036] Upon conclusion of expansion of the antigen reactive T cells, the population of antigen-reactive T cells can then be determined using various methods well known in the art. However, it is generally preferred that the determination will use an ELISPOT assay and/or a FACS assay in which a labeled construct comprising MHC-bound neoantigen is used as a fluorescence marker as is described in more detail below. As will be readily appreciated, such methods not only provide a qualitative result, but may also be used to quantify the immune response in a subject. Most typically, a threshold value is established that is reflective or predictive of an immune response (e.g., expanded antigen-reactive T cells present at an abundance of at least 0.5%, or at least 1.0%, or at least 1.5%, or at least 3% within an expansion culture).
Examples
[0037] The following examples use CMV as a model system for a viral vaccine in human, which is a common and well characterized virus. In particular, the 65 kDa lower matrix phosphoprotein (pp65) is the main component of the enveloped subviral particle and an immunodominant antigen recognized by both CD4 and CD8 T cells as is schematically shown in
[0038] While synthetic peptides can be used for all of the single peptide, the examples below employed a recombinant pp65.sub.495-503 peptide that was produced from a construct as is shown in
[0039] More particularly, peripheral blood was drawn from two CMV-seropositive, HLA A2 0201 positive subjects using venipuncture. Monocytes were isolated using the EasySep™ Human Monocyte Isolation Kit (commercially available from Stem cell Technologies) or following other known methods of CD14-based enrichment from PBMCs. To further mature and differentiate the monocytes to dendritic cells, IL-4, GM-CSF, and TNF-α were employed. To that end, monocytes were treated with the CellXVivo Human Monocyte-derived DC Differentiation Kit (commercially available from RD Systems).
[0040] The so prepared dendritic cells were then exposed to pp65 as full-length protein (see full length sequence below), as polytope (see full length sequence below), as crude cell lysate of recombinant E. coli expressing pp65, as His-purified pp65, as pp65 peptide pool as described above, or as pp65.sub.495-503 peptide fragment (see
[0041]
[0042] As can be readily seen from
[0043] Antigen reactive T cells were then detected and/or quantified using a standard ELISPOT assay as well as a FACS analysis using fluorescence labeled dextramer that was decorated with MHC to which was bound the peptide antigen (e.g., pp65.sub.495-503 peptide fragment). As can be seen from the FACS results shown in
[0044] In particular, T cell lines were generated as described for
[0045] In addition, as can be seen from the key data shown in
[0046] Sequences
[0047] The amino acid sequence of the pp65 full length protein is shown in SEQ ID NO:1.
[0048] The amino acid sequence of the pp65 Polytope (31mers with flexible linker) is shown in SEQ ID NO:2. The calculated binding affinities for sequences within the polytope are shown below:
TABLE-US-00001 TABLE 1 Predicted binding sequence affinity (HLA-A2 0201) NLVPMVATV (SEQ ID NO: 3) 29 YTSAFVFPT (SEQ ID NO: 4) 33 RIFAELEGV (SEQ ID NO: 5) 34 LMNGQQIFL (SEQ ID NO: 6) 44 MLNIPSINV (SEQ ID NO: 7) 54 QMWQARLTV (SEQ ID NO: 8) 64 RLLQTGIHV (SEQ ID NO: 9) 66 SIYVYALPL (SEQID NO: 10) 79 ALFFFDIDL (SEQID NO: 11) 82 IMLDVAFTS (SEQ ID NO: 12) 85 YLESFCEDV (SEQ ID NO: 13) 133
TABLE-US-00002 TABLE 2 Predicted binding affinity Sequence (HLA-DRB10101) TGIHVRVSQPSLILVSQ (SEQ ID NO: 14) 5.6 SHEHFGLLCPKSIPGL (SEQ ID NO: 15) 5.6 ERNGFTVLCPKNMIIK (SEQ ID NO: 16) 7.5 YALPLKMLNIPSINVHH (SEQ ID NO: 17) 7.6
[0049] An exemplary synthetic DNA template for creating neoepitope peptides in vitro is depicted below, and the corresponding sequences are shown in SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, and SEQ ID NO:21 respectively. Table 3 lists a variety of other sequence constructs used in the experiment of
TABLE-US-00003 TABLE 3 Table 3. IVT&T peptides: Met-25 mer-GKCCPGCC pp65-1 ETRLLQTGIHVRVSQPSLILVSQYT (SEQ ID NO: 22) pp65-2 QEPMSIYVYALPLKMLNIPSINVHH (SEQ ID NO: 23) pp65-3 AVIHASGKQMWQARLTVSGLAWTRQ (SEQ ID NO: 24) pp65-4 QWKEPDVYYTSAFVFPTKDVALRHV (SEQ ID NO: 25) pp65-5 IGDQYVKVYLESFCEDVPSGKLFMH (SEQ ID NO: 26) pp65-6 FMRPHERNGFTVLCPKNMIIKPGKI (SEQ ID NO: 27) pp65-7 IMLDVAFTSHEHFGLLCPKSIPGLS (SEQ ID NO: 28) pp65-8 LRQYDPVAALFFFDIDLLLQRGPQY (SEQ ID NO: 29) pp65-9 WQAGILARNLVPMVATVQGQNLKYQ (SEQ ID NO: 30) pp65-10 FWDANDIYRIFAELEGVWQPAAQPK (SEQ ID NO: 31) pp65-11 GLSISGNLLMNGQQIFLEVQAIRET (SEQ ID NO: 32)
[0050] As shown in
[0051] As used herein, the term “administering” a pharmaceutical composition or drug refers to both direct and indirect administration of the pharmaceutical composition or drug, wherein direct administration of the pharmaceutical composition or drug is typically performed by a health care professional (e.g., physician, nurse, etc.), and wherein indirect administration includes a step of providing or making available the pharmaceutical composition or drug to the health care professional for direct administration (e.g., via injection, infusion, oral delivery, topical delivery, etc.). It should further be noted that the terms “prognosing” or “predicting” a condition, a susceptibility for development of a disease, or a response to an intended treatment is meant to cover the act of predicting or the prediction (but not treatment or diagnosis of) the condition, susceptibility and/or response, including the rate of progression, improvement, and/or duration of the condition in a subject.
[0052] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the full scope of the present disclosure, and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the claimed invention.
[0053] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the full scope of the concepts disclosed herein. The disclosed subject matter, therefore, is not to be restricted except in the scope of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.