IMMU-23. NEOANTIGEN-DIRECTED CELLULAR THERAPY IN A PRECLINICAL MOUSE MODEL OF MALIGNANT GLIOMA

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi96-vi97
Author(s):  
Max Schaettler ◽  
Gavin Dunn
Keyword(s):  
T Cells ◽  
Cell Therapy ◽  
Cd8 T Cells ◽  
Cellular Therapy ◽  
Immunological Tolerance ◽  
Dependent Manner ◽  
Adoptive Cellular Therapy ◽  
Specific Expression ◽  
Cervical Lymph Nodes

Abstract Adoptive cellular therapy in the form of CAR T cells or TCR engineered T cells has emerged as a novel approach in the treatment of both solid and hematologic malignancies. Neoantigens generated by tumor somatic mutations represent potentially attractive therapeutic targets in this context owing to their tumor-specific expression and circumvention of immunological tolerance. However, existing cell therapy systems generally target self-proteins or virally overexpressed antigens that fail to recapitulate the features of endogenous tumor neoantigens. Thus, there exists a need for a model in which tumor-specific neoantigens can be targeted via adoptive cellular therapy. Prior work from our lab identified the Imp3D81N mutation (mImp3) within GL261 as a neoantigen recognized by CD8 T cells in both intracranial tumors and draining cervical lymph nodes. To generate a system for targeting this neoantigen, we isolated and cloned mImp3-specific TCRs through a single-cell sort followed by a nested multiplexed PCR reaction. The specificity and functionality of these isolated TCRs was determined through introduction into a T cell hybridoma, identifying a top candidate based upon a high degree of cytokine production and specificity for the mutant epitope. A TCR transgenic mouse was then generated in which more than 90% of all T cells were CD8 T cells bearing this mImp3-specific TCR. T cells isolated from this mouse display specificity for the mImp3 peptide and display in vitro reactivity to GL261 and other cell lines in a mImp3-dependent manner. Therefore, this model represents the first TCR transgenic targeting a brain tumor neoantigen, opening the door for further investigation into cell therapy against this class of antigens.

Human CIK Maintain Their In Vitro and In Vivo Anti-Tumor Ability after Cryopreservation.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1062-1062
Author(s):  
Jeanette Baker ◽  
Kevin Sheehan ◽  
Gina Monterola ◽  
Nancy Staines ◽  
Robert S. Negrin
Keyword(s):  
T Cells ◽  
Cytotoxic Activity ◽  
Cellular Therapy ◽  
Cell Activity ◽  
B Cell Lymphoma ◽  
Dependent Manner ◽  
Adoptive Cellular Therapy ◽  
Cik Cells

Abstract Adoptive cellular therapy holds promise for improving the outcome of hematopoietic cell transplantation (HCT). At present, donor lymphocyte infusion post-HCT is efficacious for only a limited number of diseases, yet can induce significant graft versus host disease (GVHD). To improve the outcome of this approach, it would be beneficial to identify populations of T cells that retain graft versus tumor (GVT) effects with reduced propensity for GVHD. We have previously described studies of murine expanded Cytokine Induced Killer (CIK) cells which are ex vivo activated and expanded T cells that express both T and NK markers. CIK cells mediate cytotoxicity both in vivo and in vitro in a non- MHC restricted NKG2D dependent manner. Human CIK cells were expanded from PBMC from 9 healthy donors, cultured with IFNg, CD3 and IL-2 and maintained in AastromRepliCell® biochambers for 21–28 days. We aimed to determine whether cryopreservation of the CIK affects viability, cytotoxicity and phenotype. Cells were cryopreserved immediately after harvest at 10x106/ml and stored in liquid nitrogen vapor phase. CIK viability was not compromised with cryopreservation and cells thawed at 1, 2, 4, 8, 10 and 28 weeks after freezing were 96% viable (range 95%–99%). Immediately upon thawing, CIK cells showed diminished cytotoxicity against the B cell lymphoma cell lines DB and SUDHL4 with 6–10% killing at the 40:1 E:T ratio. However, thawed CIK cells regained their pre-freeze cytotoxic activity against these targets within 5 hours of being placed in reactivation medium containing IL-2 at 300 IU/ml. Reactivation of the CIK cells was extended up to 48 hours but showed no further increase in cytotoxicity beyond that attained at 5 hours; nor did increasing the IL-2 concentration to 1500 IU/ml in the reactivation medium improve CIK cell activity over the same time course. Cell viability declined during reactivation, decreasing from an average 96% upon thawing to 60% over 48 hours. Thawed CIK cells placed in reactivation medium maintained their cytotoxic activity up to 14 days in vitro. The cytotoxicity of reactivated CIK cells was assessed in vivo using SCID mice inoculated IP with 1x106 human ovarian cancer UCI-101 cells expressing the firefly luciferase gene. The mice were treated weekly with 2x107 cryopreserved and thawed human CIK cells that were re-cultured for 5 hours before injection. Following each administration of CIK cells, there was a reduction of tumor signal. Weekly treatments resulted in a better survival outcome for the mice receiving CIK cells as compared to PBS control mice. This study demonstrates that human CIK cells may be reactivated after cryopreservation and regain their cytotoxic potential. These finding have important implications for the application of these cells as adoptive cellular therapy.

In Vitro Generation of Cytotoxic T Lymphocytes against MAGE A1 and MAGE A3 Derived From Healthy Donors.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4079-4079
Author(s):  
Lei Bao ◽  
Mindy M Stamer ◽  
Kimberly Dunham ◽  
Deepa Kolaseri Krishnadas ◽  
Kenneth G Lucas
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Lymphocytes ◽  
Cell Therapy ◽  
Cytotoxic T Lymphocytes ◽  
Cd8 T Cells ◽  
Target Cells ◽  
Ifn Gamma ◽  
Healthy Donors

Abstract Abstract 4079 Poster Board III-1014 MAGE A1 and MAGE A3 are cancer testis antigens that are expressed on a number of malignant tumor cells, but not by normal cells, except for male germ cells which lack HLA expression. Therefore, MAGE cytotoxic T lymphocytes are strictly tumor-specific. Adoptive transfer of antigen specific cytotoxic T lymphocytes (CTL) provides immediate graft-versus tumor effects while minimizing risk for graft-versus-host disease. The aim of the current study was to find ideal conditions for expansion of CTL targeting tumor-associated antigens from peripheral blood mononuclear cells (PBMCs) of healthy donors to be used in allogenic cell therapy. In this study we investigated the ability to generate MAGE A1 and MAGE A3 specific cytotoxic T cells using autologous dendritic cells (DC) loaded with MAGE A1 and MAGE A3 overlapping peptides. CTL lines specific for MAGE A1 and MAGE A3 were established by stimulating CD8 T cells from healthy donors with autologous dendritic cells loaded with MAGE A1 or MAGE A3 overlapping pooled peptides in round-bottomed, 96-well plates. CD8+ T cells were restimulated with the same ratio of peptide pulsed DC on days 7 and 14 in the presence of IL-2 (50 U/ml), IL-7 and IL-15 (5 ng/ml). These microcultures were screened 10 days after the third stimulation for their capacity to produce interferon-gamma (IFN-gamma) when stimulated with autologous EBV-transformed B lymphocytes (BLCL) transduced with lentivirus(LV) encoding MAGE A1 or MAGE A3 and autologous BLCL transduced with LV encoding GFP. MAGE A1 and MAGE-A3 specific IFN-gamma producing cells were rapidly expanded in OKT3 and IL2. The specificity of the rapidly expanded MAGE A1 and MAGE A3 specific T cells was confirmed by IFN-gamma production as measured by intracellular cytokine staining and ELISA as well as antigen specific cytotoxicity by a standard 51chromium (51Cr) release assay. We successfully generated MAGE A1 and MAGE A3 specific CTL lines from healthy donors using this method. Specific CTL lines showed cytotoxicity in vitro not only to target cells pulsed with MAGE A1 or MAGE A3 peptides but also to target cells transduced with LV-MAGE A1 or LV-MAGE A3. Specific cytolytic activity was accompanied by IFN-gamma secretion. These data indicate that tumor antigen specific CTL can be expanded using overlapping peptides regardless of an individual's HLA specificity. The ability to generate tumor specific CTL from donors of various HLA backgrounds provide a rationale for utilizing MAGE A1 and MAGE A3 overlapping peptides for expansion of antigen specific T cells for adoptive T-cell therapy against MAGE A1 or MAGE A3 expressing tumors. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Adoptive Cellular Therapy using Cells Enriched for NKG2D+CD3+CD8+T Cells after Autologous Transplantation for Myeloma

2013 ◽  
Vol 19 (1) ◽  
pp. 129-137 ◽  
Author(s):  
Kenneth R. Meehan ◽  
Laleh Talebian ◽  
Tor D. Tosteson ◽  
John M. Hill ◽  
Zbigniew Szczepiorkowski ◽  
...  
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Cellular Therapy ◽  
Autologous Transplantation ◽  
Adoptive Cellular Therapy

IMMU-52. EFFECTS OF IMMUNE CHECKPOINT BLOCKADE ON ANTIGEN-SPECIFIC CD8+ T CELLS FOR USE IN ADOPTIVE CELLULAR THERAPY

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi104-vi104
Author(s):  
Elizabeth Ogando-Rivas ◽  
Paul Castillo ◽  
Noah Jones ◽  
Vrunda Trivedi ◽  
Jeffrey Drake ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cellular Therapy ◽  
Checkpoint Inhibitors ◽  
Cell Subset ◽  
Checkpoint Blockade ◽  
Immune Checkpoints ◽  
Effector Memory ◽  
Dependent Manner

Abstract BACKGROUND Adoptive T-cell therapies have been successfully used as treatment for patients diagnosed with advanced cancers. Unfortunately, for some refractory cancers, they have failed. To overcome this, checkpoint inhibitors have shown to rescue immune anti-tumor responses. We hypothesized that in-vitro checkpoint blockade during T-cell stimulation and expansion with RNA-pulsed dendritic cells may enhance the activity of antigen-specific T-cells and improve the efficacy of ACT platforms. METHODS Human PBMCs were isolated from CMV seropositive donors to generate DCs and pulsed them with CMVpp65-mRNA to educate T-cells in co-culture for 15-days. We targeted pp65 antigen which is ubiquitously expressed by glioblastoma cells. Three checkpoint blockade conditions were evaluated (anti-PD1, anti-Tim3 and anti-PD1+Tim3). IL2 was added every 3 days as well as the blockade antibodies. Immunephenotyping was performed on Day-0 and Day-15. Polyfunctional antigen specific responses were evaluated upon rechallenge with CMVpp65 peptides. RESULTS CMVpp65 activated CD8+ T-cells upregulate Lag3 and Tim3 (p= < 0.0001). Tim3 blockade alone or in combination led to a significant upregulation of Lag3 expression on CD8+pp65Tetramer+ central memory, effector memory, and TEMRA T-cells. This latter T-cell subset uniquely maintain double-positive Tim3/Lag3 expression after blockade. In contrast, PD-1 blockade had minimal effects on Tim3 or Lag3 expression. In addition, IFN-g secretion was reduced in T-cells treated with Tim3 blockade in a dose-dependent manner (p= 0.004). CONCLUSION In this study, we have identified a potential activating component of Tim3 and linkage between Tim3 and Lag3 signaling upon blocking Tim3 axis during T-cell antigen presenting cell interactions that should be considered when targeting immune checkpoints for clinical use.

scholarly journals Immunoregulatory Natural Killer Cells Suppress Autoimmunity by Down-Regulating Antigen-Specific CD8+ T Cells in Mice

Endocrinology ◽  
2012 ◽  
Vol 153 (9) ◽  
pp. 4367-4379 ◽  
Author(s):  
Margret Ehlers ◽  
Claudia Papewalis ◽  
Wiebke Stenzel ◽  
Benedikt Jacobs ◽  
Klaus L. Meyer ◽  
...  
Keyword(s):  
T Cells ◽  
Immune System ◽  
Nk Cells ◽  
Natural Killer ◽  
Cd8 T Cells ◽  
Regulatory Function ◽  
Dependent Manner ◽  
Lysis Activity ◽  
Nonobese Diabetic Mice

Natural killer (NK) cells belong to the innate immune system. Besides their role in antitumor immunity, NK cells also regulate the activity of other cells of the immune system, including dendritic cells, macrophages, and T cells, and may, therefore, be involved in autoimmune processes. The aim of the present study was to clarify the role of NK cells within this context. Using two mouse models for type 1 diabetes mellitus, a new subset of NK cells with regulatory function was identified. These cells were generated from conventional NK cells by incubation with IL-18 and are characterized by the expression of the surface markers CD117 (also known as c-Kit, stem cell factor receptor) and programmed death (PD)-ligand 1. In vitro analyses demonstrated a direct lysis activity of IL-18-stimulated NK cells against activated insulin-specific CD8+ T cells in a PD-1/PD-ligand 1-dependent manner. Flow cytometry analyses revealed a large increase of splenic and lymphatic NK1.1+/c-Kit+ NK cells in nonobese diabetic mice at 8 wk of age, the time point of acceleration of adaptive cytotoxic immunity. Adoptive transfer of unstimulated and IL-18-stimulated NK cells into streptozotocin-treated mice led to a delayed diabetes development and partial disease prevention in the group treated with IL-18-stimulated NK cells. Consistent with these data, mild diabetes was associated with increased numbers of NK1.1+/c-Kit+ NK cells within the islets. Our results demonstrate a direct link between innate and adaptive immunity in autoimmunity with newly identified immunoregulatory NK cells displaying a potential role as immunosuppressors.

In Vitro Expansion of CMV-Specific T Cells from CMV Seronegative Donors.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3927-3927
Author(s):  
Stephanie Verfuerth ◽  
Arnold R. Pizzey ◽  
Shoon-Ling C. Chow ◽  
Noha Chowdhry ◽  
Stephen Mackinnon
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Cellular Therapy ◽  
T Cell Proliferation ◽  
Adoptive Cellular Therapy ◽  
Size Classes ◽  
Pulsed Dc ◽  
Ifn Γ

Abstract CMV infection is still a negative prognostic factor in hematopoietic stem cell transplantation, largely due to adverse effects of antiviral chemotherapy. Advances have been made in the development of adoptive cellular therapy for CMV with cell products derived from CMV seropositive donors. However no such cell products from CMV negative donors are currently available, although CMV negative recipients of CMV positive grafts bear the greatest risk of CMV induced morbidity and mortality. Mature DC are capable of inducing in vivo primary T cell responses. We used an in vitro culture system employing MoDC generated with GM-CSF and IL-4, pulsed with CMV lysate and matured with CD40L to induce primary immune responses to CMV. CMV-specific T cell proliferation measured by 3H-Thymidine uptake could be induced in some 6 to 9-day cultures, however, the success rate was very low, and T cells could usually not be kept alive after becoming activated. The addition of IL-15 to cultures after 7 days resulted in some improvement, although some non-CMV specific T cell proliferation in response to control lysate or in the absence of antigen also occurred in some cultures. IL-12 added to cultures from day 0 resulted in a short-term increase in T cell proliferation that was followed by increased cell death and was also not entirely CMV-specific. The real benefit of IL-15, alone or in combination with IL-12, was seen in 2-week cultures: In 6/7 cultures from different CMV seronegative donors counts of viable T cells (by trypan blue exclusion) increased up to 10-fold. Two cultures that were additionally set up with control lysate-pulsed DC to detect proliferation in response to non-CMV components of the antigen, confirmed CMV-specificity. CMV-specificity was also shown by T cell receptor (TCR) complement determining region (CDR) 3 spectratyping. TCR-BV(variable region β)-size class expression patterns across 23 BV families were very similar in pre-culture unstimulated T cells and in T cells stimulated with control lysate-pulsed DC for 2 weeks, showing the typical near-normal distribution of PCR product amongst the different size classes indicative of un-stimulated T cells. T cells co-cultured with CMV lysate-pulsed DC for 2 weeks produced very skewed spectratypes, indicative of oligoclonal T cell expansion in response to the antigen. The effect of IL-15 on T cell spectratypes from CMV antigen-driven cultures was tested using cells from another donor. With or without IL-15, post-culture spectratypes showed oligoclonal T cell expansions in the same BV families and size classes. However, despite their similar shapes, spectratypes from IL-5 containing cultures were skewed to a greater extent, possibly indicating a greater effect of IL-15 on already activated T cells. No CD8+ T cells specific for single immunodominant epitopes could be detected by staining with up to 5 different HLA-CMVpeptide-tetramers in culture output from 4/4 donors. In 1 of 2 cultures analyzed by cytokine secretion assay, a significant sub-population of T cells (1%), in CD4 positive and negative fractions, secreted IFN-γ in response to re-stimulation with CMV antigen. No IFN-γ secreting CMV-specific pre-cursor T cells were detected in fresh PBMC, as expected. Whilst further work is required to make generation of CMV specific T cells from CMV seronegative donors more reproducible and to ensure antigen-specificity, these preliminary data are encouraging for the future generation of CMV-specific T cells from CMV seronegative donors for adoptive cellular therapy.

scholarly journals IL-21–mediated Foxp3 suppression leads to enhanced generation of antigen-specific CD8+ cytotoxic T lymphocytes

Blood ◽  
2008 ◽  
Vol 111 (1) ◽  
pp. 229-235 ◽  
Author(s):  
Yongqing Li ◽  
Cassian Yee
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Cellular Therapy ◽  
Ex Vivo ◽  
Human Model ◽  
Adoptive Cellular Therapy ◽  
Specific Ctls ◽  
Regulatory Constraints

Efforts to reproducibly isolate tumor antigen–specific T cells from patients would be facilitated by removing immunoregulatory barriers. Using a human model for eliciting T-cell responses to tumor-associated antigens, we develop a novel strategy that eliminates nearly all Foxp3-expressing cells through the combination of CD25 depletion and IL-21 treatment resulting in a more than 150-fold decrease in Foxp3+ cells to virtually undetectable levels and a more than 200-fold increase in antigen-specific cytotoxic T lymphocytes (CTLs). The extent of Foxp3 elimination and degree of expansion of antigen-specific CTLs shown in this study have not previously been achievable and are unique to IL-21. We demonstrate for the first time a possible mechanism for IL-21–mediated expansion of antigen-specific CTLs that involves suppression of Foxp3-expressing cells and reversal of inhibition to tumor-associated antigen–specific CTL generation in vitro. Taken together, the combination of CD25 depletion and IL-21 exposure, by releasing regulatory constraints, leads to markedly enhanced CTL induction and represents a robust strategy for the ex vivo generation of antigen-specific T cells for adoptive cellular therapy.

scholarly journals C reactive protein impairs adaptive immunity in immune cells of patients with melanoma

2020 ◽  
Vol 8 (1) ◽  
pp. e000234
Author(s):  
Tatsuya Yoshida ◽  
Junya Ichikawa ◽  
Iulia Giuroiu ◽  
Andressa S Laino ◽  
Yuhan Hao ◽  
...  
Keyword(s):  
T Cells ◽  
Adaptive Immunity ◽  
Cd8 T Cells ◽  
Immune Checkpoint ◽  
Dependent Manner ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Link Type ◽  
Serum Crp

BackgroundHigh C reactive protein (CRP) levels have been reported to be associated with a poor clinical outcome in a number of malignancies and with programmed cell death protein 1 immune checkpoint blockade in patients with advanced cancer. Little is known about the direct effects of CRP on adaptive immunity in cancer. Therefore, we investigated how CRP impacted the function of T cells and dendritic cells (DCs) from patients with melanoma.MethodsThe effects of CRP on proliferation, function, gene expression and phenotype of patient T cells and DCs, and expansion of MART-1 antigen-specific T cells were analyzed by multicolor flow cytometry and RNA-seq. Additionally, serum CRP levels at baseline from patients with metastatic melanoma treated on the Checkmate-064 clinical trial were assessed by a Luminex assay.ResultsIn vitro, CRP inhibited proliferation, activation-associated phenotypes and the effector function of activated CD4+ and CD8+ T cells from patients with melanoma. CRP-treated T cells expressed high levels of interleukin-1β, which is known to enhance CRP production from the liver. CRP also suppressed formation of the immune synapse and inhibited early events in T-cell receptor engagement. In addition, CRP downregulated the expression of costimulatory molecules on mature DCs and suppressed expansion of MART-1-specific CD8+ T cells in a dose-dependent manner by impacting on both T cells and antigen-presenting cells. High-serum CRP levels at baseline were significantly associated with a shorter survival in both nivolumab-treated and ipilimumab-treated patients.ConclusionsThese findings suggest that high levels of CRP induce an immunosuppressivemilieuin melanoma and support the blockade of CRP as a therapeutic strategy to enhance immune checkpoint therapies in cancer.Trial registration numberNCT01783938andNCT02983006.

scholarly journals Targeted De-Methylation of the FOXP3-TSDR Is Sufficient to Induce Physiological FOXP3 Expression but Not a Functional Treg Phenotype

2021 ◽  
Vol 11 ◽  
Author(s):  
Christopher Kressler ◽  
Gilles Gasparoni ◽  
Karl Nordström ◽  
Dania Hamo ◽  
Abdulrahman Salhab ◽  
...  
Keyword(s):  
Cellular Therapy ◽  
Foxp3 Expression ◽  
Immunological Tolerance ◽  
T Cell Proliferation ◽  
Adoptive Cellular Therapy ◽  
Enhancer Element ◽  
Effector Cells ◽  
Epigenetic Editing ◽  
Treg Phenotype

CD4+ regulatory T cells (Tregs) are key mediators of immunological tolerance and promising effector cells for immuno-suppressive adoptive cellular therapy to fight autoimmunity and chronic inflammation. Their functional stability is critical for their clinical utility and has been correlated to the demethylated state of the TSDR/CNS2 enhancer element in the Treg lineage transcription factor FOXP3. However, proof for a causal contribution of the TSDR de-methylation to FOXP3 stability and Treg induction is so far lacking. We here established a powerful transient-transfection CRISPR-Cas9-based epigenetic editing method for the selective de-methylation of the TSDR within the endogenous chromatin environment of a living cell. The induced de-methylated state was stable over weeks in clonal T cell proliferation cultures even after expression of the editing complex had ceased. Epigenetic editing of the TSDR resulted in FOXP3 expression, even in its physiological isoform distribution, proving a causal role for the de-methylated TSDR in FOXP3 regulation. However, successful FOXP3 induction was not associated with a switch towards a functional Treg phenotype, in contrast to what has been reported from FOXP3 overexpression approaches. Thus, TSDR de-methylation is required, but not sufficient for a stable Treg phenotype induction. Therefore, targeted demethylation of the TSDR may be a critical addition to published in vitro Treg induction protocols which so far lack FOXP3 stability.

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