Role of Stroma in Modulating Immune Checkpoint Blockade on T-Cells in Pancreatic Cancer

2019 ◽  
Vol 229 (4) ◽  
pp. e203
Author(s):  
Prateek Sharma ◽  
Bharti Garg ◽  
Anthony Ferrantella ◽  
Vrishketan Sethi ◽  
Saba Kurtom ◽  
...  
Open Biology ◽  
2021 ◽  
Vol 11 (11) ◽  
Author(s):  
Courtney T. Stump ◽  
Kevin Roehle ◽  
Nataly Manjarrez Orduno ◽  
Stephanie K. Dougan

Radiation has been a pillar of cancer therapy for decades. The effects of radiation on the anti-tumour immune response are variable across studies and have not been explicitly defined in poorly immunogenic tumour types. Here, we employed combination checkpoint blockade immunotherapy with stereotactic body radiation therapy and examined the effect on tumour growth and immune infiltrates in subcutaneous and orthotopic mouse models of pancreatic cancer. Although immune checkpoint blockade and radiation were ineffective alone, their combination produced a modest growth delay in both irradiated and non-irradiated tumours that corresponded with significant increases in CD8+ T cells, CD4+ T cells and tumour-specific T cells as identified by IFNγ ELISpot. We conclude that radiation enhances priming of tumour-specific T cells in poorly immunogenic tumours and that the frequency of these T cells can be further increased by combination with immune checkpoint blockade.


2021 ◽  
Vol 14 (9) ◽  
pp. 101170
Author(s):  
Vera Bauer ◽  
Fatima Ahmetlić ◽  
Nadine Hömberg ◽  
Albert Geishauser ◽  
Martin Röcken ◽  
...  

2021 ◽  
Vol 9 (1) ◽  
pp. e001460 ◽  
Author(s):  
Xiuting Liu ◽  
Graham D Hogg ◽  
David G DeNardo

The clinical success of immune checkpoint inhibitors has highlighted the central role of the immune system in cancer control. Immune checkpoint inhibitors can reinvigorate anti-cancer immunity and are now the standard of care in a number of malignancies. However, research on immune checkpoint blockade has largely been framed with the central dogma that checkpoint therapies intrinsically target the T cell, triggering the tumoricidal potential of the adaptive immune system. Although T cells undoubtedly remain a critical piece of the story, mounting evidence, reviewed herein, indicates that much of the efficacy of checkpoint therapies may be attributable to the innate immune system. Emerging research suggests that T cell-directed checkpoint antibodies such as anti-programmed cell death protein-1 (PD-1) or programmed death-ligand-1 (PD-L1) can impact innate immunity by both direct and indirect pathways, which may ultimately shape clinical efficacy. However, the mechanisms and impacts of these activities have yet to be fully elucidated, and checkpoint therapies have potentially beneficial and detrimental effects on innate antitumor immunity. Further research into the role of innate subsets during checkpoint blockade may be critical for developing combination therapies to help overcome checkpoint resistance. The potential of checkpoint therapies to amplify innate antitumor immunity represents a promising new field that can be translated into innovative immunotherapies for patients fighting refractory malignancies.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii108-ii108
Author(s):  
Jayeeta Ghose ◽  
Baisakhi Raychaudhuri ◽  
Kevin Liu ◽  
William Jiang ◽  
Pooja Gulati ◽  
...  

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.


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

2020 ◽  
Vol 8 (Suppl 2) ◽  
pp. A5.1-A5
Author(s):  
A Martinez-Usatorre ◽  
E Kadioglu ◽  
C Cianciaruso ◽  
B Torchia ◽  
J Faget ◽  
...  

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.


Cancers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2762 ◽  
Author(s):  
Xinrui Zhao ◽  
Chunlin Shao

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.


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