scholarly journals Characterising Tumour and Microenvironmental Responses to R-CHOP in Immunocompetent Mouse Models of DLBCL

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2401-2401
Author(s):  
Bernard D Maybury ◽  
Findlay Bewicke-Copley ◽  
Peter Johnson ◽  
Jude Fitzgibbon ◽  
Dinis Pedro Calado
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cell Line ◽  
Rna Sequencing ◽  
Mouse Models ◽  
Cd8 T Cells ◽  
Research Funding ◽  
Lymphoma Cells ◽  
Pre Treatment

Abstract R-CHOP chemoimmunotherapy has been the standard of care for diffuse large B cell lymphoma (DLBCL) for 20 years. The lymphoma and microenvironment responses to R-CHOP have not been studied in detail in an experimental setting. Here we describe the early effects of R-CHOP on lymphoma cells and infiltrating T cells in novel mouse models of DLBCL. Using cre-lox recombination to induce B cell-specific overexpression of MYC, IKK2 and BLIMP1 drives the formation of unique high grade B cell lymphomas with an activated B cell (ABC) phenotype and an intact immune environment. Using flow cytometry and RNA sequencing we compare the response to R-CHOP in these mice with the response in a cell line lymphoma model. We also performed partial splenectomy prior to R-CHOP treatment to study paired samples pre-treatment and at relapse by whole-exome and RNA sequencing. Treatment with anti-CD20 alone induced very few changes in lymphoma cells in either model, but CHOP chemotherapy in combination with rituximab induced changes in lymphoma cell and T cell phenotypes. In particular, extracellular matrix and cell adhesion gene signatures were enriched in lymphoma cells after treatment, in both disease models studied. After injection of the cell line, memory populations of CD8+ T cells are expanded but this change is reversed by chemotherapy, whereas in the cre-lox conditional model 40% of CD8+ T cells are exhausted with smaller chemotherapy-associated changes. In the paired pre-treatment/relapse samples we observed clonal selection and increased mutation burden at relapse, associated with diverse transcriptional changes. Mutations were newly detected or expanded at relapse in various lymphoma-associated genes including Trp53, Samhd1 and Ubr5. Our results suggest that DLBCL responses to treatment and biology at relapse are principally driven by tumour-specific factors, but there are some commonalities across model systems which may be amenable to therapeutic modulation. The differences in T cell responses between conditional tumours and cell-line tumours demonstrate the limitations of cell lines for studying treatment responses in vivo. Figure 1 Figure 1. Disclosures Johnson: Boehringer Ingelheim: Consultancy; Janssen: Consultancy; Kite Pharma: Honoraria; Oncimmune: Consultancy; Epizyme: Consultancy, Research Funding; Bristol-Myers: Honoraria; Incyte: Honoraria; Genmab: Honoraria; Takeda: Honoraria; Novartis: Honoraria; Morphosys: Honoraria; Celgene: Honoraria; Kymera: Honoraria. Fitzgibbon: Epizyme: Research Funding. Calado: Myricx Pharma: Consultancy, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company, Patents & Royalties: Cancer Treatments. WO patent WO 2020/128475 A1 (2020).

scholarly journals Analysis of CAR-T and Immune Cells within the Tumor Micro-Environment of Diffuse Large B-Cell Lymphoma Post CAR-T Treatment By Multiplex Immunofluorescence

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 678-678 ◽  
Author(s):  
Pei-Hsuan Chen ◽  
Mikel Lipschitz ◽  
Kyle Wright ◽  
Philippe Armand ◽  
Caron A. Jacobson ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cd8 T Cells ◽  
Research Funding ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Abstract BACKGROUND: Axicabtagene ciloleucel is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy that shows efficacy in patients with refractory diffuse large B-cell lymphoma (DLBCL), primary mediastinal B-cell lymphoma and transformed follicular lymphoma after failure of conventional therapy. However, the exact mechanism of anti-tumor immunity is poorly understood, in part due to the dearth of data on the events in the tumor micro-environment (TME) that occur upon exposure to CAR-T cells. We sought to quantify and characterize both CAR-T cells and non-CAR T cells within the TME of DLBCL using tissue biopsy samples collected in the ZUMA-1 multicenter trial of CAR-T cell therapy for patients with refractory DLBCL. METHODS: Tumor samples obtained from patients 5-30 days (median 10 days) after CAR-T infusion ("CAR-treated", n=14) and randomly-selected untreated ("untreated ", n=15) archival DLBCL tissue samples were analyzed by multiplex immunofluorescence using formalin-fixed, paraffin embedded tissue sections, with successive labeling by the primary antibodies KIP-1 and/or KIP-3 (recognizing separate CD19 CAR epitopes), PAX5, PD-1, CD4, and CD8, followed by secondary amplification and tyramide-conjugated fluorophores. For each case, at least 3 representative 20x fields of view were selected and imaged using a multispectral imaging platform. Two specific image analysis algorithms were designed to accurately identify CD4 and CD8 T cells and PAX5+ DLBCL cells simultaneously, then to threshold PD-1 and KIP-1/-3 by relative fluorescent units (RFU) in each phenotype. RESULTS: We identified CAR T-cells within the fixed biopsy samples of CAR-treated DLBCLs by immunostaining with CAR T-cell specific antibody KIP-1; at the timepoints analyzed, CAR T-cells comprised only a small minority of total T- cells (<2%) and included CD4+ and CD8+ T-cells. Immunostaining with a second antibody, KIP-3, validated the presence of CAR T-cells in these cases and confirmed the KIP-1 results. Expression of the T cell activation marker PD-1 was detected among majority of KIP-1+ cells. Further analysis that included KIP1-negative cells revealed that the percentage of CD8+ cells co-expressing PD-1 across all CD8+ cells was higher in the CAR-treated DLBCLs compared to the untreated DLBCLs (mean 50.1% vs 17.5%, p<0.0001 with unpaired t test ), indicating CD8 T cell activation within the tumor environment. In contrast, PD-1 positivity across CD4+ T cells were equivalent between the two groups (mean 21.8% vs 21.6%, ns with unpaired t test). The percentages of total, CD4+, and CD8+ T-cell populations in the TME were similar between the CAR-treated DLBCL and untreated biopsies. CONCLUSIONS: CD4+ and CD8+ CAR-T cells can be detected in CAR-treated DLBCL patient tissue biopsies by multiplex immunofluorescence. At the time points analyzed to date, CAR-T cells comprise only a small percentage of all T-cells (<2%) within the TME. However, the presence of gene marked T cells with downregulated CAR protein expression is also possible. The activation marker PD-1 is preferentially expressed by KIP-1-negative CD8+ T cells compared to CD4+ T cells in CAR-T treated DLBCLs relative to untreated DLBCLs. These data implicate preferential activation of CD8+ non-CAR "by-stander" T-cells in the post CAR-T TME, and the possible benefit of combining PD-1 blockade with CAR-T therapy in DLBCL. *PH.C and M.L share equal contribution. Disclosures Armand: Otsuka: Research Funding; Affimed: Consultancy, Research Funding; Pfizer: Consultancy; Infinity: Consultancy; Adaptive: Research Funding; Merck: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Roche: Research Funding; Tensha: Research Funding. Roberts:KITE: Employment. Rossi:KITE: Employment. Bot:KITE: Employment. Go:KITE: Employment. Rodig:Merck: Research Funding; Bristol Myers Squibb: Research Funding; Affimed: Research Funding; KITE: Research Funding.

Targeting DKK1 for the Immunotherapy of B-Cell Lymphomas.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 465-465
Author(s):  
Jianfei Qian ◽  
Sungyoul Hong ◽  
Liang Zhang ◽  
Yuhuan Zheng ◽  
Haiyan Li ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Tumor Cells ◽  
Cell Lines ◽  
Cd8 T Cells ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Lymphoma Cells ◽  
Specific Ctls

Abstract Abstract 465 Immunotherapy may complement the current treatments for lymphomas. The lack of suitable shared lymphoma-associated antigens limits its applicability. Therefore, identification and utilization of novel and more potent tumor-associated antigens, particularly those shared among patients, are urgently needed to improve the efficacy of immunotherapy in the diseases. Recent studies have shown that Dickkopf-1 (DKK1), a secreted protein and Wnt signaling pathway inhibitor, is highly expressed by myeloma and other tumor cells, and is absent from normal tissues and organs except placenta and prostate. In the present study we demonstrated that DKK1 is also overexpressed in mantle cell lymphoma (MCL) and diffuse large B-cell lymphoma (DLBCL). Using DKK1 peptide-pulsed dendritic cells (DCs), we successfully generated HLA-A*0201+ DKK1-specific CTL lines and clones in vitro. These CTLs effectively lysed DKK1+/HLA-A*0201+ lymphoma cell lines Jeko-1 and Granta 519 cells, but not DKK1-/HLA-A*0201+ BJAB, RL and Mino cells nor DKK1+/HLA-A*020- CA46 and Daudi cells. Furthermore, the T-cell clones efficiently killed DKK1+/HLA-A*0201+ primary B-cell lymphoma cells from patients but not lymphoma cells from DKK1–/HLA-A*0201+ patients. HLA-ABC or HLA-A*0201 blocking mAbs significantly inhibited T cell-mediated cytotoxicity against peptide-pulsed T2 cells (P < .01, compared with medium control). No inhibitory effect was observed with mAb against HLA-DR and isotype control IgG. The results indicate that the cytotoxicity was attributed to MHC class I and more specifically, HLA-A*0201-restricted CD8+ CTLs. The CTLs did not kill DKK1–/HLA-A*0201+ DCs, B cells, or PBMCs, These results suggest that the CTLs recognized DKK1 peptides that are naturally processed and presented in the context of HLA-A*0201 molecules on lymphoma cells. To determine the in vivo antitumor activity, NOD-SCID and SCID-hu mice were used for lymphoma cell lines and primary lymphoma cells, respectively. Mice were treated with DKK1-specific CTLs after tumor established in NOD-SCID and SCID-hu mice. Control mice were treated with naïve CD8+ T cells or PBS alone. Tumor burden was measured according to levels of circulating human B2M, and survival rates were determined. Low levels (< 50 ng/ml) of circulating human B2M were detected in group treated DKK1-specific CTLs, while high levels (≥ 150 ng/ml) of circulating human B2M were detected in control mice. In SCID-hu model, X-ray examination showed that established tumors were eradicated in 60% mice treated with DKK1-specific CTLs, while large tumor burdens were found in all control mice. In NOD-SCID model, 40% of mice survived with the treatment of DKK1-specific CTLs. TUNEL assay further confirmed that tumor cells were lysed by DKK1-specific CTLs not naïve CD8+ T cells. These results indicate that DKK1-specific CTLs are able to eradicate established, patient-derived primary B- cell lymphoma in the hosts and adoptive transfer of DKK1-specific CTLs may be used for B-cell lymphoma therapy. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Beyond PD-1: Investigating the Therapeutic Potential of TIGIT Blockade in DLBCL

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 391-391 ◽  
Author(s):  
Nicole Sunseri ◽  
Xiufen Chen ◽  
Noemie Wald ◽  
Julie Preillon ◽  
Sonali M. Smith ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cd8 T Cells ◽  
Research Funding ◽  
Cell Lymphoma ◽  
Ex Vivo ◽  
B Cell Lymphoma ◽  
Isotype Control

Background: The PD-1/PD-L1 axis is a dominant cancer immune escape pathway, and PD-1 blockade therapy has greatly benefited patients with select solid tumors and lymphomas. Unfortunately, anti-PD-1 monotherapy has limited efficacy against relapsed/refractory (r/r) diffuse large B cell lymphoma (DLBCL) - a disease where new therapies are needed. Because numerous inhibitory checkpoint receptors have been implicated in driving tumor-specific T cell dysfunction, we hypothesized that combinatorial checkpoint blockade therapy (CBT) would enhance the activity of PD-1-based therapy in r/r DLBCL. T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) is a recently identified co-inhibitory receptor expressed on dysfunctional tumor-infiltrating T cells. PD-1 and TIGIT co-blockade therapy has demonstrated impressive activity in pre-clinical solid tumor and myeloma models. However, the degree to which TIGIT is involved in mediating T cell suppression in DLBCL is not fully known. Methods: TIGIT expression on lymphoma-infiltrating T cells (LITs) from 18 fresh lymphoma samples was analyzed by flow cytometry. Multiplex IHC on tissue microarrays (TMAs) was also performed to investigate TIGIT expression in DLBCL samples. The syngeneic murine A20 B cell lymphoma model was employed to study: 1) the kinetics of TIGIT and other co-receptor expression on LITs, 2) the association of TIGIT expression with effector function among LITs, and 3) the effectiveness of anti-TIGIT mono- and combination CBT in mice with established A20 lymphomas. A20 lymphoma tumors were established in groups of Balb/c mice by subcutaneous (SQ) injections of 5 x 106 cells. Expression of TIGIT and other co-receptors in A20 LITs was examined by flow cytometry at various time points. Function of TIGIT+ LITs was assessed by examining cytokine production following ex vivo stimulation with PMA and ionomycin. To test the efficacy of TIGIT blockade, mice received intraperitoneal injections of anti-TIGIT, anti-PD-1, anti-4-1BB, or combinations of these antibodies. Treatments began once tumors reached a diameter of 10 mm and were continued every 3 days for 5 doses. Tumor growth was monitored and compared to that in A20-bearing mice treated with isotype control antibodies. In some experiments, mice that achieved complete tumor rejection following single or dual CBT were re-challenged with A20 cells to investigate immunological memory responses. Results: Across a variety of human lymphomas, flow cytometric analysis revealed that TIGIT was broadly upregulated on LITs, including regulatory T cells and conventional CD4+and CD8+ T cells (Figure A and B). TIGIT expression on LITs in DLBCL was particularly high. Nearly all TIGIT+ LITs were also PD-1+, suggesting that these receptors co-orchestrate a T cell dysfunctional state in the lymphoma environment. Multiplex immunofluorescence staining of DLBCL samples demonstrated that TIGIT was most highly expressed on CD8+ T cells and that TIGIT+ T cells tended to be localized near, and in some cases, surrounding CD20+ lymphoma cells. Consistent with observations in human lymphomas, LITs isolated from murine A20 lymphoma commonly co-expressed TIGIT and PD-1, and the degree of expression correlated directly with tumor volume. This correlation was also present for other co-receptors, including 4-1BB, TIM3, and CTLA-4. Ex vivo restimulation of A20 LITs revealed that TIGIT+ T cells produced lower levels of effector cytokines, such as TNF-α, compared with TIGIT- T cells. In mice with established A20 lymphomas, both TIGIT and PD-1 mono-blockade led to modest delays in tumor outgrowth compared with mice treated with isotype control antibodies. Strikingly, however, combined PD-1 and TIGIT blockade resulted in complete rejection of A20 lymphomas in most mice and led to significantly prolonged survival compared to mice treated with single agent CBT (Figure C). Combination TIGIT and 4-1BB CBT was also remarkably effective in driving rejection of A20 lymphomas, and led to remarkable memory responses. Conclusions: TIGIT promotes immune tolerance in the DLBCL environment. While TIGIT monotherapy has anti-lymphoma activity, combinatorial CBT incorporating anti-TIGIT antibodies drives extremely potent rejection of established lymphomas in mice. These results provide rationale for further study of TIGIT blockade as a therapeutic strategy in r/r lymphomas, including DLBCL. Disclosures Sunseri: iTeos Therapeutics: Research Funding. Wald:iTeos Therapeutics: Employment. Preillon:iTeos Therapeutics: Employment. Smith:Portola Pharmaceuticals: Research Funding. Driessens:iTeos Therapeutics: Employment. Kline:Merck: Honoraria; Merck: Research Funding.

183 Overcoming immunotherapy resistance in T cell-inflamed lung cancer

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A197-A197
Author(s):  
Brendan Horton ◽  
Brendan Horton ◽  
Duncan Morgan ◽  
Noor Momin ◽  
Vidit Bhandarkar ◽  
...  
Keyword(s):  
Lung Cancer ◽  
T Cells ◽  
T Cell ◽  
Cell Line ◽  
Cancer Patients ◽  
Rna Sequencing ◽  
Mechanistic Study ◽  
Nsclc Cell Line ◽  
Effector Molecule ◽  
Effector Molecules

BackgroundTumor infiltrating T cells (TIL) are highly correlated with response to checkpoint blockade immunotherapy (CBT) in melanoma. However, in non-small cell lung cancer (NSCLC), 61% of patients have TIL, but only 32% respond to CBT. It is unknown how these T cell-inflamed tumors are resistant to CBT. Understanding and overcoming this resistance would greatly increase the number of cancer patients who benefit from CBT.MethodsTo understand lung-specific anti-tumor immune responses, a NSCLC cell line derived from an autochthonous murine lung cancer (KP cell line) was transplanted into syngeneic C57BL/6 mice subcutaneously or intravenously. To study antigen-specific responses, the KP cell line was engineered with SIY and 2C TCR transgenic T cells, which are specific for SIY, were adoptively transferred into tumor-bearing animals.ResultsSubcutaneous KP tumors responded to CBT (aCTLA-4 and aPD-L1) with significant tumor regression while lung KP tumors were CBT resistant. Immunohistochemistry found that this was not due to lack of T cell infiltration, as lung tumors contained 10-fold higher numbers of CD8+ TIL than subcutaneous tumors. Single cell RNA sequencing of TIL uncovered that CD8+ TIL in lung lesions had blunted effector molecule expression that correlated with a lack of IL-2 signaling. Adoptive transfer of naïve, tumor-reactive 2C T cells resulted in equally robust T cell proliferation in both the inguinal and mediastinal lymph nodes (LNs). However, RNA sequencing of adoptively transferred 2C T cells isolated 3-days after transfer from draining LNs identified that T cells activated in the mediastinal LN had reduced levels of IL-2 signaling and blunted effector functions early during priming. Flow cytometry confirmed that T cells primed in the mediastinal LNs did not express CD25, GZMB, or IFN-g, while T cells in inguinal LNs upregulated all three of these effector molecules. Delivery of IL-2 and IL-12 during priming was sufficient to restore effector molecule expression on 2C T cells in mediastinal LNs. Analysis of published patient data identified that a subset of lung cancer patients showed a sizable population of CD8+ TIL with low IL-2 signaling and low expression of effector molecules, including common targets of CBT.ConclusionsImmunotherapy resistance in T cell-inflamed tumors is due to defective CD8+ T cell effector differentiation. IL-2-based therapies could enhance differentiation of functional CD8+ effector T cells and could turn immunotherapy resistant tumors to immunotherapy sensitive tumors. This is the first mechanistic study providing evidence for a distinct type of T cell dysfunction resistant to current CBT.Ethics ApprovalThis study was approved by MIT’s Committee on Animal Care, protocol number 0220-006-23.

scholarly journals 677 Reverse abscopal effect: intertumoral heterogeneity suppresses systemic CD8 T cell-mediated antitumor immunity and confers PD-1 inhibitor resistance in synchronous melanoma

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A705-A705
Author(s):  
Shuyang Qin ◽  
Booyeon Han ◽  
Alexander Chacon ◽  
Alexa Melucci ◽  
Alyssa Williams ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Line ◽  
Cd8 T Cells ◽  
Antitumor Immunity ◽  
Immune Escape ◽  
Cd8 T Cell ◽  
Abscopal Effect ◽  
Immunogenic Tumor ◽  
Ifn Γ

BackgroundDespite recent advancements in systemic therapy, only a minority of metastatic patients develop meaningful clinical responses to immune checkpoint inhibitors. Inherent genetic instability of melanoma generates genomically and microenvironmentally distinct metastases. These different tumor microenvironments (TMEs) contain numerous T cell suppression mechanisms, such as upregulation of the PD-1/PD-L1 exhaustion pathway. However, as synchronous metastases share one host immune system, intertumoral heterogeneity may result in increasing cross-talk between metastases that impairs systemic antitumor immunity and promotes PD-1 immunotherapy resistance.MethodsYUMM 1.7 (less immunogenic) and YUMMER 1.7 (more immunogenic cell line derived from YUMM following UVB irradiation) melanoma cell lines were simultaneously injected into opposite flanks of the same mice as a model of synchronous melanoma. We assessed tumor growth in wildtype, interferon-gamma (IFN-γ) knockout, and CD8-depleted mice as well as in response to PD-1 inhibitor. We characterized the TME with flow cytometry and performed TCR sequencing on tumor-infiltrating CD8 T cells.ResultsDistinct TMEs were observed for YUMM and YUMMER tumors simultaneously grown in the same mouse. The presence of the less immunogenic YUMM tumor allows the more immunogenic YUMMER tumors to escape IFN-γ and CD8 T cell-mediated rejection, despite abundant tumor-infiltrating, clonally expanded CD8 T cells. Identical immunodominant CD8 T cell clones were found in both YUMM and YUMMER tumors within the same mouse. Synchronous YUMMER-infiltrating CD8 T cells exhibit suppressed phenotypes, including increased persistence of surface PD-1 and decreased surface CD107a expressions. Simultaneously, these synchronous YUMMER tumors additionally upregulate macrophage surface PD-L1 expression, which potentially contributes to tumor immune escape. Lastly, synchronous YUMMER tumors become resistant to PD-1 inhibition, in direct contrast to control YUMMER tumors.ConclusionsIn a host with multiple melanoma lesions, immunogenicity of all tumors contribute to the systemic antitumor immune response. We show that two synchronous tumors with synonymous mutations (<40%), as is the case with metastatic patients, lead to skewed CD8 T cell expansion of the same clones in both tumors. The presence of a less immunogenic tumor prevents CD8 and IFN-γ mediated rejection of the more immunogenic tumor. Furthermore, CD8 T cells in the more immunogenic tumor exhibit decreased effector function and increased resistance to PD-1 blockade, as tumor-infiltrating macrophages concurrently become more immunosuppressive. These results are highly suggestive of a “reverse abscopal effect,” by which immunologically “cold” tumors generate systemic immunosuppression that facilitate PD-1 immunotherapy resistance and immune escape of all other tumors in synchronous metastatic melanoma patients.AcknowledgementsWe would like to thank Dr. Marcus Bosenberg from the Department of Dermatology at Yale University for kindly gifting us with the YUMMER 1.7 murine melanoma cell line.Ethics ApprovalAnimal experiments were approved by the University Committee on Animal Resources and performed in accordance with University of Rochester approved guidelines.

scholarly journals Phase 2 Study of Combination of Cytarabine, Idarubicin, and Nivolumab for Initial Therapy of Patients with Newly Diagnosed Acute Myeloid Leukemia

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 815-815
Author(s):  
Farhad Ravandi ◽  
Naval Daver ◽  
Guillermo Garcia-Manero ◽  
Christopher B Benton ◽  
Philip A Thompson ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
T Cell Subsets ◽  
Newly Diagnosed ◽  
Effector Cells ◽  
T Effector Cells ◽  
Grade 3

Abstract Background: Blocking PD-1/PD-L1 pathways enhances anti-leukemia responses by enabling T-cells in murine models of AML (Zhang et al, Blood 2009). PD-1 positive CD8 T-cells are increased in bone marrow (BM) of pts with AML (Daver et al, AACR 2016). PD1 inhibition has shown activity in AML (Berger et al, Clin Cancer Res 2008). We hypothesized that addition of nivolumab to an induction regimen of ara-C and idarubicin may prolong relapse-free survival (RFS) and overall survival (OS); this study was designed to determine the feasibility of this combination. Methods: Pts with newly diagnosed acute myeloid leukemia (by WHO criteria; ≥20% blasts) and high risk MDS (≥10% blasts) were eligible to participate if they were 18-65 yrs of age and had adequate performance status (ECOG ≤3) and organ function (LVEF ≥ 50%; creatinine ≤ 1.5 g mg/dL, bilirubin ≤ 1.5 mg/dL and transaminases ≤ 2.5 times upper limit of normal). Treatment included 1 or 2 induction cycles of ara-C 1.5 g/m2 over 24 hours (days 1-4) and Idarubicin 12 mg/m2 (days 1-3). Nivolumab 3 mg/kg was started on day 24 ± 2 days and was continued every 2 weeks for up to a year. For pts achieving complete response (CR) or CR with incomplete count recovery (CRi) up to 5 consolidation cycles of attenuated dose ara-C and idarubicin was administered at approximately monthly intervals. Eligible pts received an allogeneic stem cell transplant (alloSCT) at any time during the consolidation or thereafter. Results: 3 pts with relapsed AML were treated at a run-in phase with a dose of nivolumab 1 mg/kg without specific drug-related toxicity. Subsequently, 32 pts (median age 53 yrs; range, 26-65) were treated as above including 30 with AML (24 de novo AML, 2 therapy-related AML, 3 secondary AML and 1 therapy-related secondary AML) and 2 high risk MDS. Pre-treatment genetic risk by ELN criteria was 11 adverse, 16 intermediate, and 5 favorable, including 2 FLT3 -ITD mutated, 5 NPM1 mutated, and 7 TP53 mutated. All 32 pts were evaluable for response and 23 (72%) achieved CR/CRi (19 CR, 4 CRi). The 4-week and 8 week mortality was 6% and 6%. The median number of doses of nivolumab received was 6 (range, 0-13); one pt did not receive nivolumab due to insurance issues. 9 pts underwent an alloSCT. After a median follow-up of 8.3 mths (range, 1.5-17.0) the median RFS among the responding pts has not been reached (range, 0.1 - 15.8 mths) and the median OS has not been reached (range 0.5-17.0 mths). Grade 3/4 immune mediated toxicities have been observed in 5 pts and include rash, pancreatitis, and colitis. Other grade 3/4 toxicities thought to be potentially related to nivolumab include cholecystitis in one pt. 9 pts proceeded to an alloSCT. Donor source was matched related in 2, matched unrelated in 6 and haplo-identical in 1 pt. Conditioning regimen was Fludarabine plus busulfan-based in 8, and fludarabine plus melphalan in 1 pt. 4 pts developed graft versus host disease (GVHD)(grade I/II in 3, grade III/IV in 1), which responded to treatment in 3. Multicolor flow-cytometry studies are conducted by the Immunotherapy Platform on baseline (prior to first dose of nivolumab) and on-treatment BM aspirate and peripheral blood to assess the T-cell repertoire and expression of co-stimulatory receptors and ligands on T-cell subsets and leukemic blasts, respectively. The baseline BM was evaluated on 23 of the 32 evaluable pts, including 18 responders and 5 non-responders. Pts who achieved a CR/CRi had a trend of higher frequency of live CD3+ total T cell infiltrate as compared to non-responders in the baseline BM aspirates (Fig 1A). We evaluated expression of immune markers on T cell subsets: CD4 T effector cells [Teff]: CD3+CD4+CD127lo/+Foxp3-, CD4 T regulatory cells [Treg]: CD3+CD4+CD127-Foxp3+, and CD8 T cells. At baseline, BM of non-responders had significantly higher percentage of CD4 T effector cells co-expressing the inhibitory markers PD1 and TIM3 (p&lt;0.05) and a trend towards higher percentage of CD4 T effector cells co-expressing PD1 and LAG3 compared to responders (Fig 1B). Co-expression of TIM3 or LAG3 on PD1+ T cells have been shown to be associated with an exhausted immune phenotype in AML (Zhou et al., Blood 2011). Conclusion: Addition of nivolumab to ara-C and anthracycline induction chemotherapy is feasible and safe in younger pts with AML. Among the pts proceeding to alloSCT the risk of GVHD is not significantly increased. Figure 1 Figure 1. Disclosures Daver: Pfizer Inc.: Consultancy, Research Funding; Otsuka America Pharmaceutical, Inc.: Consultancy; Sunesis Pharmaceuticals, Inc.: Consultancy, Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; Bristol-Myers Squibb Company: Consultancy, Research Funding; Kiromic: Research Funding; Karyopharm: Consultancy, Research Funding; Jazz: Consultancy; Immunogen: Research Funding; Daiichi-Sankyo: Research Funding; Incyte Corporation: Honoraria, Research Funding. Thompson: Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees. Jabbour: Bristol-Myers Squibb: Consultancy. Takahashi: Symbio Pharmaceuticals: Consultancy. DiNardo: Novartis: Honoraria, Research Funding; Daiichi-Sankyo: Honoraria, Research Funding; AbbVie: Honoraria, Research Funding; Agios: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Sharma: Jounce: Consultancy, Other: stock, Patents & Royalties: Patent licensed to Jounce; Astellas: Consultancy; EMD Serono: Consultancy; Amgen: Consultancy; Astra Zeneca: Consultancy; GSK: Consultancy; Consetellation: Other: stock; Evelo: Consultancy, Other: stock; Neon: Consultancy, Other: stock; Kite Pharma: Consultancy, Other: stock; BMS: Consultancy. Cortes: BMS: Consultancy, Research Funding; Sun Pharma: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Teva: Research Funding; ImmunoGen: Consultancy, Research Funding; ARIAD: Consultancy, Research Funding. Kantarjian: Delta-Fly Pharma: Research Funding; Amgen: Research Funding; ARIAD: Research Funding; Novartis: Research Funding; Bristol-Meyers Squibb: Research Funding; Pfizer: Research Funding.

scholarly journals A Novel Approach for Treatment of T-Cell Malignancies: Targeting T-Cell Receptor Vβ Families

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 28-29
Author(s):  
Jie Wang ◽  
Katarzyna Urbanska ◽  
Prannda Sharma ◽  
Mathilde Poussin ◽  
Reza Nejati ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cell Line ◽  
Cell Lines ◽  
Cell Receptor ◽  
Brentuximab Vedotin ◽  
T Cell Lymphomas ◽  
T Cell Malignancies

Background: Peripheral T-cell lymphomas (PTCL) encompass a highly heterogeneous group of T-cell malignancies and are generally associated with a poor prognosis. Combination chemotherapy results in consistently poorer outcomes for T-cell lymphomas compared with B-cell lymphomas.1 There is an urgent clinical need to develop novel approaches to treatment of PTCL. While CD19- and CD20-directed immunotherapies have been successful in the treatment of B-cell malignancies, T-cell malignancies lack suitable immunotherapeutic targets. Brentuximab Vedotin, a CD30 antibody-drug conjugate, is not applicable to PTCL subtypes which do not express CD30.2 Broadly targeting pan-T cell markers is predicted to result in extensive T-cell depletion and clinically significant immune deficiency; therefore, a more tumor-specific antigen that primarily targets the malignant T-cell clone is needed. We reasoned that since malignant T cells are clonal and express the same T-cell receptor (TCR) in a given patient, and since the TCR β chain in human α/β TCRs can be grouped into 24 functional Vβ families targetable by monoclonal antibodies, immunotherapeutic targeting of TCR Vβ families would be an attractive strategy for the treatment of T-cell malignancies. Methods: We developed a flexible approach for targeting TCR Vβ families by engineering T cells to express a CD64 chimeric immune receptor (CD64-CIR), comprising a CD3ζ T cell signaling endodomain, CD28 costimulatory domain, and the high-affinity Fc gamma receptor I, CD64. T cells expressing CD64-CIR are predicted to be directed to tumor cells by Vβ-specific monoclonal antibodies that target tumor cell TCR, leading to T cell activation and induction of tumor cell death by T cell-mediated cytotoxicity. Results: This concept was first evaluated in vitro using cell lines. SupT1 T-cell lymphoblasts, which do not express a native functioning TCR, were stably transduced to express a Vβ12+ MART-1 specific TCR, resulting in a Vβ12 TCR expressing target T cell line.3 Vβ family specific cytolysis was confirmed by chromium release assays using co-culture of CD64 CIR transduced T cells with the engineered SupT1-Vβ12 cell line in the presence of Vβ12 monoclonal antibody. Percent specific lysis was calculated as (experimental - spontaneous lysis / maximal - spontaneous lysis) x 100. Controls using no antibody, Vβ8 antibody, and untransduced T cells did not show significant cytolysis (figure A). Next, the Jurkat T cell leukemic cell line, which expresses a native Vβ8 TCR, was used as targets in co-culture. Again, Vβ family target specific cytolysis was achieved in the presence of CD64 CIR T cells and Vβ8, but not Vβ12 control antibody. Having demonstrated Vβ family specific cytolysis in vitro using target T cell lines, we next evaluated TCR Vβ family targeting in vivo. Immunodeficient mice were injected with SupT1-Vβ12 or Jurkat T cells with the appropriate targeting Vβ antibody, and either CD64 CIR T cells or control untransduced T cells. The cell lines were transfected with firefly luciferase and tumor growth was measured by bioluminescence. The CD64 CIR T cells, but not untransduced T cells, in conjunction with the appropriate Vβ antibody, successfully controlled tumor growth (figure B). Our results provide proof-of-concept that TCR Vβ family specific T cell-mediated cytolysis is feasible, and informs the development of novel immunotherapies that target TCR Vβ families in T-cell malignancies. Unlike approaches that target pan-T cell antigens, this approach is not expected to cause substantial immune deficiency and could lead to a significant advance in the treatment of T-cell malignancies including PTCL. References 1. Coiffier B, Brousse N, Peuchmaur M, et al. Peripheral T-cell lymphomas have a worse prognosis than B-cell lymphomas: a prospective study of 361 immunophenotyped patients treated with the LNH-84 regimen. The GELA (Groupe d'Etude des Lymphomes Agressives). Ann Oncol Off J Eur Soc Med Oncol. 1990;1(1):45-50. 2. Horwitz SM, Advani RH, Bartlett NL, et al. Objective responses in relapsed T-cell lymphomas with single agent brentuximab vedotin. Blood. 2014;123(20):3095-3100. 3. Hughes MS, Yu YYL, Dudley ME, et al. Transfer of a TCR Gene Derived from a Patient with a Marked Antitumor Response Conveys Highly Active T-Cell Effector Functions. Hum Gene Ther. 2005;16(4):457-472. Figure Disclosures Schuster: Novartis, Genentech, Inc./ F. Hoffmann-La Roche: Research Funding; AlloGene, AstraZeneca, BeiGene, Genentech, Inc./ F. Hoffmann-La Roche, Juno/Celgene, Loxo Oncology, Nordic Nanovector, Novartis, Tessa Therapeutics: Consultancy, Honoraria.

scholarly journals Single cell profiling of T and B cell repertoires following SARS-CoV-2 mRNA vaccine

2021 ◽  
Author(s):  
Suhas Sureshchandra ◽  
Sloan A. Lewis ◽  
Brianna Doratt ◽  
Allen Jankeel ◽  
Izabela Ibraim ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Single Cell ◽  
Cd8 T Cells ◽  
Natural Infection ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cd4 T Cell ◽  
Cell Responses

mRNA based vaccines for SARS-CoV-2 have shown exceptional clinical efficacy providing robust protection against severe disease. However, our understanding of transcriptional and repertoire changes following full vaccination remains incomplete. We used single-cell RNA sequencing and functional assays to compare humoral and cellular responses to two doses of mRNA vaccine with responses observed in convalescent individuals with asymptomatic disease. Our analyses revealed enrichment of spike-specific B cells, activated CD4 T cells, and robust antigen-specific polyfunctional CD4 T cell responses in all vaccinees. On the other hand, CD8 T cell responses were both weak and variable. Interestingly, clonally expanded CD8 T cells were observed in every vaccinee, as observed following natural infection. TCR gene usage, however, was variable, reflecting the diversity of repertoires and MHC polymorphism in the human population. Natural infection induced expansion of larger CD8 T cell clones occupied distinct clusters, likely due to the recognition of a broader set of viral epitopes presented by the virus not seen in the mRNA vaccine. Our study highlights a coordinated adaptive immune response where early CD4 T cell responses facilitate the development of the B cell response and substantial expansion of effector CD8 T cells, together capable of contributing to future recall responses.

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