WES of melanoma tumors treated with combined immune checkpoint blockade
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ABSTRACT:
PROVIDER: EGAS00001003857 | EGA |
REPOSITORIES: EGA
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Project description:Immune checkpoint blockade is able to achieve durable responses in a subset of patients, however we lack a satisfying comprehension of the underlying mechanisms of anti-CTLA-4 and anti-PD-1 induced tumor rejection. To address these issues we utilized mass cytometry to comprehensively profile the effects of checkpoint blockade on tumor immune infiltrates in human melanoma and murine tumor models. These analyses reveal a spectrum of tumor infiltrating T cell populations that are highly similar between tumor models and indicate that checkpoint blockade targets only specific subsets of tumor infiltrating T cell populations. Anti-PD-1 predominantly induces the expansion of specific tumor infiltrating exhausted-like CD8 T cell subsets. In contrast, anti-CTLA-4 induces the expansion of an ICOS+ Th1-like CD4 effector population in addition to engaging specific subsets of exhausted-like CD8 T cells. Thus, our findings indicate that anti-CTLA-4 and anti-PD-1 checkpoint blockade induced immune responses are driven by distinct cellular mechanisms.
2017-08-10 | GSE100808 | GEO
Project description:Immune checkpoint blockade is able to achieve durable responses in a subset of patients, however we lack a satisfying comprehension of the underlying mechanisms of anti-CTLA-4 and anti-PD-1 induced tumor rejection. To address these issues we utilized mass cytometry to comprehensively profile the effects of checkpoint blockade on tumor immune infiltrates in human melanoma and murine tumor models. These analyses reveal a spectrum of tumor infiltrating T cell populations that are highly similar between tumor models and indicate that checkpoint blockade targets only specific subsets of tumor infiltrating T cell populations. Anti-PD-1 predominantly induces the expansion of specific tumor infiltrating exhausted-like CD8 T cell subsets. In contrast, anti-CTLA-4 induces the expansion of an ICOS+ Th1-like CD4 effector population in addition to engaging specific subsets of exhausted-like CD8 T cells. Thus, our findings indicate that anti-CTLA-4 and anti-PD-1 checkpoint blockade induced immune responses are driven by distinct cellular mechanisms.
2017-08-10 | GSE100807 | GEO
Project description:Single cell transcriptomes of CD45+ cells from KPC tumor subcutaneous allografts, either treated with PD-1+CTLA-4 checkpoint blockade or treatment-naïve.
2022-08-01 | GSE206668 | GEO
Project description:This dataset contains 16S and WMS data for gut (fecal) microbiome samples taken from patients treated with combined anti-CTLA-4 and anti-PD-1 checkpoint blockade for advanced melanoma.
| EGAS00001004885 | EGA
Project description:Cytotoxic T-lymphocyte associated antigen-4 (CTLA-4) and Programmed death-1 (PD-1) are immunoregulatory receptors expressed on T cells that play important roles in suppressing immune responses to cancer. Although monoclonal antibodies that target CTLA-4 or PD-1 stimulate therapeutic anti-tumour T cell responses, the tumour antigens recognized by checkpoint blockade immunotherapy remain undefined. Herein, we use genomics and bioinformatics approaches to identify tumour-specific mutant proteins as a major class of T cell rejection antigens following αPD-1 and/or αCTLA-4 treatment of mice bearing progressively growing sarcomas. We validate this conclusion by showing that (a) the predicted mutant epitopes associate with MHC class I molecules of the tumour; (b) T cells specific for these mutant epitopes infiltrate tumours; and (c) therapeutic vaccines incorporating these mutant epitopes induce tumour rejection comparably to checkpoint blockade immunotherapy. Whereas, T cells with the same antigen specificity are present in progressively growing tumours in control mice, tumour-specific T cells in αPD-1- and/or αCTLA-4-treated mice express some overlapping but mostly treatment-specific transcriptional profiles that render them capable of tumour rejection. Thus, tumour-specific mutant antigens are not only important targets of checkpoint blockade therapy but also can be used to identify tumour antigen-specific T cells that function as biomarkers of successful anti-tumour responses.
2014-11-07 | GSE62771 | GEO
Project description:Immune checkpoint blockade (ICB) therapy has demonstrated promising clinical results in oncology and is currently one of the most sought-after immunotherapies for tumors. However, there are a number of issues with ICB therapy, including low response rates and a lack of effective efficacy predictors. Gasdermin-mediated pyroptosis is a typical form of inflammatory death mode, but it is unclear whether ICB treatment can trigger its occurrence or whether gasdermin expression has any effect on the response rate to ICB treatment. Herein, we discovered that high expression of gasdermin protein was associated with a favorable tumor immune microenvironment and a favorable prognosis in head and neck squamous cell carcinoma (HNSCC), and taking advantage of the mouse HNSCC cell line 4MOSC1 (responsive to CTLA-4 blockade) and 4MOSC2 (resistant to CTLA-4 blockade) orthotopic models, we also demonstrated that CTLA-4 blockade treatment induced gasdermin-mediated pyroptosis of tumor cells and that the expression of gasdermin was positively associated with the effectiveness of CTLA-4 blocking treatment. Mechanistically, through RNA sequencing, flow cytometry, ELISA, Western blotting and RT-PCR, we discovered that CTLA-4 blockade activated CD8+ T cells in the tumor and increased the levels of the cytokines TNF-α and IFN-γ in the tumor microenvironment, and that TNF-α and IFN-γ synergistically activated the STAT1/IRF1 axis, inducing tumor cell pyroptosis and the release of large amounts of inflammatory substances and chemokines such as CXCL10.
2023-04-01 | GSE201367 | GEO
Project description:Distinct cellular mechanisms underlie anti-CTLA-4 and anti-PD-1 checkpoint blockade
| PRJNA393126 | ENA
Project description:T cells receive numerous positive and negative signals during primary antigen encounter that control their proliferation and function, but how these signals are integrated to modulate T cell memory has not been fully characterized. In these studies, we demonstrate that combining seemingly opposite signals, CTLA-4 blockade and rapamycin-mediated mTOR inhibition, during in vivo T cell priming leads to both an increase in the frequency of memory CD8+ T cells and improved memory responses to tumors and bacterial challenges. This enhanced efficacy corresponds to increased early expansion and memory precursor differentiation of CD8+ T cells and increased mitochondrial biogenesis and spare respiratory capacity in memory CD8+ T cells in mice treated with anti-CTLA-4 and rapamycin during immunization. Collectively, these results reveal that mTOR inhibition cooperates with rather than antagonizes blockade of CTLA-4, promoting unrestrained effector function and proliferation and an optimal metabolic program for CD8+ T cell memory. Total RNA was isolated from FACS-sorted, antigen-specific CD8+T cells from different treatment conditions at 5 or 35 days after primary T cell activation
2015-01-31 | E-GEOD-63022 | biostudies-arrayexpress
Project description:<p>Immune checkpoint inhibitors are effective cancer treatments, but molecular determinants of clinical benefit are unknown. Ipilimumab and tremelimumab are antibodies against cytotoxic T-lymphocyte antigen 4 (CTLA-4). Anti-CTLA-4 treatment prolongs overall survival in patients with melanoma. CTLA-4 blockade activates T cells and enables them to destroy tumor cells.</p> <p>We obtained tumor tissue from patients with melanoma who were treated with ipilimumab or tremelimumab. Whole-exome sequencing was performed on tumors and matched blood samples. Somatic mutations and candidate neoantigens generated from these mutations were characterized. Neoantigen peptides were tested for the ability to activate lymphocytes from ipilimumab-treated patients.</p> <p>Malignant melanoma exomes from 64 patients treated with CTLA-4 blockade were characterized with the use of massively parallel sequencing. A discovery set consisted of 11 patients who derived a long-term clinical benefit and 14 patients who derived a minimal benefit or no benefit. Mutational load was associated with the degree of clinical benefit (P = 0.01) but alone was not sufficient to predict benefit. Using genomewide somatic neoepitope analysis and patient-specific HLA typing, we identified candidate tumor neoantigens for each patient. We elucidated a neo-antigen landscape that is specifically present in tumors with a strong response to CTLA-4 blockade. We validated this signature in a second set of 39 patients with melanoma who were treated with anti-CTLA-4 antibodies. Predicted neoantigens activated T cells from the patients treated with ipilimumab.</p>
| phs001041 | dbGaP
Project description:Combination immunotherapy is being developed with the goal of enhancing anti-tumor immunity. Despite remarkable clinical responses, most patients do not experience complete responses from combination checkpoint blockade treatments. Therefore, a need exists to further explore the mechanisms of resistance to these therapies. Here, we investigate whether tumor burden could be an important factor in determining the treatment outcomes of combination checkpoint blockade. We found that while combined anti-CTLA-4 and anti-PD-1 improves control of established tumors, this combination can paradoxically compromise anti-tumor immunity in the low tumor burden (LTB) state in pre-clinical models as well as in melanoma patients. This paradoxical outcome results from treatment-induced deletion of tumor-specific T cells that is mediated through IFN-γ. Activated tumor-specific T cells express higher levels of IFN-γ receptor and are more susceptible to apoptosis. As a result, combination treatment alters the T cell repertoire landscape, skewing the distribution of T cells toward lower frequency clonotypes. Deficiency of the IFN-γ receptor on immune cells restores anti-tumor activity. Additionally, tumor-specific T cells lacking the IFN-γ receptor demonstrate a significant survival advantage compared to their wild-type counterparts in tumor-bearing mice receiving combination therapy. Finally, we show that combination therapy induces significantly higher levels of IFN-γ in the low versus high tumor burden state on a per cell basis, reflecting their less exhausted immune status. This elevated IFN-γ secretion in the LTB state therefore contributes to the development of an immune-intrinsic mechanism of resistance to combination checkpoint blockade. Our report underscores the importance of achieving the optimal magnitude of immune stimulation for successful immunotherapy strategies.
2018-10-24 | GSE121694 | GEO