scholarly journals IMMU-19. TARGETING GLIOBLASTOMA IMMUNOSUPPRESSION AND TREATMENT RESISTANCE WITH IBRUTINIB IN COMBINATION WITH STEREOTACTIC RADIATION AND IMMUNE CHECKPOINT BLOCKADE

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii108-ii108
Author(s):  
Jayeeta Ghose ◽  
Baisakhi Raychaudhuri ◽  
Kevin Liu ◽  
William Jiang ◽  
Pooja Gulati ◽  
...  
Keyword(s):  
T Cells ◽  
Combination Therapy ◽  
Median Survival ◽  
Immune Checkpoint ◽  
Survival Benefit ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade ◽  
Control Group ◽  
Triple Combination ◽  
Triple Combination Therapy

Abstract BACKGROUND Glioblastoma (GBM) is associated with systemic and intratumoral immunosuppression. Part of this immunosuppression is mediated by myeloid derived suppressor cells (MDSCs). Preclinical evidence shows that ibrutinib, a tyrosine kinase inhibitor FDA approved for use in chronic lymphocytic leukemia and known to be CNS penetrant, can decrease MDSC generation and function. Also, focal radiation therapy (RT) synergizes with anti-PD-1 therapy in mouse GBM models. Thus, we aimed to test the combination of these approaches on immune activation and survival in a preclinical immune-intact GBM mouse model. METHODS C57BL/6 mice intracranially implanted with the murine glioma cell line GL261-Luc2 were divided into 8 groups consisting of treatments with ibrutinib, RT (10 Gy SRS), or anti-PD-1 individually or in each combination (along with a no treatment control group). Immune cell subset changes (flow-cytometry) and animal survival (Kaplan-Meier) were assessed (n=10 mice per group). RESULTS Median survival of the following groups including control (28 days), ibrutinib (27 days), RT (30 days) or anti-PD-1 (32 days) showed no significant differences. However, a significant improvement in median survival was seen in mice given combinations of ibrutinib+RT (35 days), ibrutinib+anti-PD-1 (38 days), and triple therapy with ibrutinib+RT+anti-PD-1 (48 days, p < 0.05) compared to controls or single treatment groups. The reproducible survival benefit of triple combination therapy was abrogated in the setting of CD4+ and CD8+ T cell depletion. Contralateral intracranial tumor re-challenge in long-term surviving mice suggested generation of tumor-specific immune memory responses. The immune profile of the tumor microenvironment (TME) showed increased cytotoxic CD8+ T cells and decreased MDSCs and regulatory T cells in the triple combination therapy mice compared to controls. CONCLUSION The combination of ibrutinib, focal RT, and anti-PD-1 immune checkpoint blockade led to a significant survival benefit compared to controls in a preclinical model of GBM.

scholarly journals Combination of vasculature targeting, hypofractionated radiotherapy, and immune checkpoint inhibitor elicits potent antitumor immune response and blocks tumor progression

2021 ◽  
Vol 9 (2) ◽  
pp. e001636
Author(s):  
Stefano Pierini ◽  
Abhishek Mishra ◽  
Renzo Perales-Linares ◽  
Mireia Uribe-Herranz ◽  
Silvia Beghi ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Combination Therapy ◽  
Tumor Growth ◽  
Tumor Progression ◽  
Immune Checkpoint ◽  
Blood Perfusion ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade ◽  
Triple Combination Therapy

BackgroundTumor endothelial marker 1 (TEM1) is a protein expressed in the tumor-associated endothelium and/or stroma of various types of cancer. We previously demonstrated that immunization with a plasmid-DNA vaccine targeting TEM1 reduced tumor progression in three murine cancer models. Radiation therapy (RT) is an established cancer modality used in more than 50% of patients with solid tumors. RT can induce tumor-associated vasculature injury, triggering immunogenic cell death and inhibition of the irradiated tumor and distant non-irradiated tumor growth (abscopal effect). Combination treatment of RT with TEM1 immunotherapy may complement and augment established immune checkpoint blockade.MethodsMice bearing bilateral subcutaneous CT26 colorectal or TC1 lung tumors were treated with a novel heterologous TEM1-based vaccine, in combination with RT, and anti-programmed death-ligand 1 (PD-L1) antibody or combinations of these therapies, tumor growth of irradiated and abscopal tumors was subsequently assessed. Analysis of tumor blood perfusion was evaluated by CD31 staining and Doppler ultrasound imaging. Immunophenotyping of peripheral and tumor-infiltrating immune cells as well as functional analysis was analyzed by flow cytometry, ELISpot assay and adoptive cell transfer (ACT) experiments.ResultsWe demonstrate that addition of RT to heterologous TEM1 vaccination reduces progression of CT26 and TC1 irradiated and abscopal distant tumors as compared with either single treatment. Mechanistically, RT increased major histocompatibility complex class I molecule (MHCI) expression on endothelial cells and improved immune recognition of the endothelium by anti-TEM1 T cells with subsequent severe vascular damage as measured by reduced microvascular density and tumor blood perfusion. Heterologous TEM1 vaccine and RT combination therapy boosted tumor-associated antigen (TAA) cross-priming (ie, anti-gp70) and augmented programmed cell death protein 1 (PD-1)/PD-L1 signaling within CT26 tumor. Blocking the PD-1/PD-L1 axis in combination with dual therapy further increased the antitumor effect and gp70-specific immune responses. ACT experiments show that anti-gp70 T cells are required for the antitumor effects of the combination therapy.ConclusionOur findings describe novel cooperative mechanisms between heterologous TEM1 vaccination and RT, highlighting the pivotal role that TAA cross-priming plays for an effective antitumor strategy. Furthermore, we provide rationale for using heterologous TEM1 vaccination and RT as an add-on to immune checkpoint blockade as triple combination therapy into early-phase clinical trials.

scholarly journals Combination anti–CTLA-4 plus anti–PD-1 checkpoint blockade utilizes cellular mechanisms partially distinct from monotherapies

2019 ◽  
Vol 116 (45) ◽  
pp. 22699-22709 ◽  
Author(s):  
Spencer C. Wei ◽  
Nana-Ama A. S. Anang ◽  
Roshan Sharma ◽  
Miles C. Andrews ◽  
Alexandre Reuben ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Combination Therapy ◽  
Cd8 T Cells ◽  
Immune Checkpoint ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade ◽  
Cell Populations ◽  
Mass Cytometry ◽  
Therapy Targets

Immune checkpoint blockade therapy targets T cell-negative costimulatory molecules such as cytotoxic T lymphocyte antigen-4 (CTLA-4) and programmed cell death-1 (PD-1). Combination anti–CTLA-4 and anti–PD-1 blockade therapy has enhanced efficacy, but it remains unclear through what mechanisms such effects are mediated. A critical question is whether combination therapy targets and modulates the same T cell populations as monotherapies. Using a mass cytometry-based systems approach, we comprehensively profiled the response of T cell populations to monotherapy and combination anti–CTLA-4 plus anti–PD-1 therapy in syngeneic murine tumors and clinical samples. Most effects of monotherapies were additive in the context of combination therapy; however, multiple combination therapy-specific effects were observed. Highly phenotypically exhausted cluster of differentiation 8 (CD8) T cells expand in frequency following anti–PD-1 monotherapy but not combination therapy, while activated terminally differentiated effector CD8 T cells expand only following combination therapy. Combination therapy also led to further increased frequency of T helper type 1 (Th1)-like CD4 effector T cells even though anti–PD-1 monotherapy is not sufficient to do so. Mass cytometry analyses of peripheral blood from melanoma patients treated with immune checkpoint blockade therapies similarly revealed mostly additive effects on the frequencies of T cell subsets along with unique modulation of terminally differentiated effector CD8 T cells by combination ipilimumab plus nivolumab therapy. Together, these findings indicate that dual blockade of CTLA-4 and PD-1 therapy is sufficient to induce unique cellular responses compared with either monotherapy.

scholarly journals Immune checkpoint blockade impairs immunosuppressive mechanisms of regulatory T cells in B-cell lymphoma

2021 ◽  
Vol 14 (9) ◽  
pp. 101170
Author(s):  
Vera Bauer ◽  
Fatima Ahmetlić ◽  
Nadine Hömberg ◽  
Albert Geishauser ◽  
Martin Röcken ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
B Cell ◽  
Immune Checkpoint ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade

scholarly journals Non-conventional Inhibitory CD4+Foxp3–PD-1hi T Cells as a Biomarker of Immune Checkpoint Blockade Activity

Cancer Cell ◽  
2018 ◽  
Vol 34 (4) ◽  
pp. 691 ◽  
Author(s):  
Roberta Zappasodi ◽  
Sadna Budhu ◽  
Matthew D. Hellmann ◽  
Michael A. Postow ◽  
Yasin Senbabaoglu ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Checkpoint ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade

scholarly journals O4 Mechanisms of lung cancer hyper-progression promoted by PD-1 immune checkpoint blockade

2020 ◽  
Vol 8 (Suppl 2) ◽  
pp. A5.1-A5
Author(s):  
A Martinez-Usatorre ◽  
E Kadioglu ◽  
C Cianciaruso ◽  
B Torchia ◽  
J Faget ◽  
...  
Keyword(s):  
Lung Cancer ◽  
T Cells ◽  
Regulatory T Cells ◽  
Immune Checkpoint ◽  
Immune Cell ◽  
Immune Checkpoint Blockade ◽  
Genetically Engineered ◽  
Checkpoint Blockade ◽  
Therapeutic Benefits ◽  
Angiopoietin 2

BackgroundImmune checkpoint blockade (ICB) with antibodies against PD-1 or PD-L1 may provide therapeutic benefits in patients with non-small cell lung cancer (NSCLC). However, most tumours are resistant and cases of disease hyper-progression have also been reported.Materials and MethodsGenetically engineered mouse models of KrasG12Dp53null NSCLC were treated with cisplatin along with antibodies against angiopoietin-2/VEGFA, PD-1 and CSF1R. Tumour growth was monitored by micro-computed tomography and the tumour vasculature and immune cell infiltrates were assessed by immunofluorescence staining and flow cytometry.ResultsCombined angiopoietin-2/VEGFA blockade by a bispecific antibody (A2V) modulated the vasculature and abated immunosuppressive macrophages while increasing CD8+effector T cells in the tumours, achieving disease stabilization comparable or superior to cisplatin-based chemotherapy. However, these immunological responses were unexpectedly limited by the addition of a PD-1 antibody, which paradoxically enhanced progression of a fraction of the tumours through a mechanism involving regulatory T cells and macrophages. Elimination of tumour-associated macrophages with a CSF1R-blocking antibody induced NSCLC regression in combination with PD-1 blockade and cisplatin.ConclusionsThe immune cell composition of the tumour determines the outcome of PD-1 blockade. In NSCLC, high infiltration of regulatory T cells and immunosuppressive macrophages may account for tumour hyper-progression upon ICB.Disclosure InformationA. Martinez-Usatorre: None. E. Kadioglu: None. C. Cianciaruso: None. B. Torchia: None. J. Faget: None. E. Meylan: None. M. Schmittnaegel: None. I. Keklikoglou: None. M. De Palma: None.

scholarly journals Radiotherapy-Mediated Immunomodulation and Anti-Tumor Abscopal Effect Combining Immune Checkpoint Blockade

Cancers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2762 ◽  
Author(s):  
Xinrui Zhao ◽  
Chunlin Shao
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Immune Checkpoint ◽  
Tumor Regression ◽  
Combined Therapy ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade ◽  
Abscopal Effect ◽  
Specific Circumstance

Radiotherapy (RT) is a conventional method for clinical treatment of local tumors, which can induce tumor-specific immune response and cause the shrinkage of primary tumor and distal metastases via mediating tumor infiltration of CD8+ T cells. Ionizing radiation (IR) induced tumor regression outside the radiation field is termed as abscopal effect. However, due to the mobilization of immunosuppressive signals by IR, the activated CD8+T cells are not sufficient to maintain a long-term positive feedback to make the tumors regress completely. Eventually, the “hot” tumors gradually turn to “cold”. With the advent of emerging immunotherapy, the combination of immune checkpoint blockade (ICB) and local RT has produced welcome changes in stubborn metastases, especially anti-PD-1/PD-L1 and anti-CTLA-4 which have been approved in clinical cancer treatment. However, the detailed mechanism of the abscopal effect induced by combined therapy is still unclear. Therefore, how to formulate a therapeutic schedule to maximize the efficacy should be took into consideration according to specific circumstance. This paper reviewed the recent research progresses in immunomodulatory effects of local radiotherapy on the tumor microenvironment, as well as the unique advantage for abscopal effect when combined with ICB, with a view to exploring the potential application value of radioimmunotherapy in clinic.

scholarly journals Absence of central tolerance in Aire-deficient mice synergizes with immune-checkpoint inhibition to enhance antitumor responses

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Asiel A. Benitez ◽  
Sara Khalil-Agüero ◽  
Anjali Nandakumar ◽  
Namita T. Gupta ◽  
Wen Zhang ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Checkpoint ◽  
Immune Checkpoint Blockade ◽  
Tumor Rejection ◽  
Checkpoint Blockade ◽  
Cell Repertoire ◽  
Activated T Cells ◽  
Central Tolerance ◽  
Tolerance Breakdown ◽  
Deficient Mice

AbstractThe endogenous anti-tumor responses are limited in part by the absence of tumor-reactive T cells, an inevitable consequence of thymic central tolerance mechanisms ensuring prevention of autoimmunity. Here we show that tumor rejection induced by immune checkpoint blockade is significantly enhanced in Aire-deficient mice, the epitome of central tolerance breakdown. The observed synergy in tumor rejection extended to different tumor models, was accompanied by increased numbers of activated T cells expressing high levels of Gzma, Gzmb, Perforin, Cxcr3, and increased intratumoural levels of Cxcl9 and Cxcl10 compared to wild-type mice. Consistent with Aire’s central role in T cell repertoire selection, single cell TCR sequencing unveiled expansion of several clones with high tumor reactivity. The data suggest that breakdown in central tolerance synergizes with immune checkpoint blockade in enhancing anti-tumor immunity and may serve as a model to unmask novel anti-tumor therapies including anti-tumor TCRs, normally purged during central tolerance.

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