Similar Datasets
Project description:Most ovarian cancers are infiltrated by prognostically relevant activated T cells1-3, yet exhibit low response rates to immune checkpoint inhibitors4. Memory B cell and plasma cell infiltrates have previously been associated with better outcomes in ovarian cancer5,6, but the nature and functional relevance of these responses are controversial. Here, using 3 independent cohorts that in total comprise 534 patients with high-grade serous ovarian cancer, we show that robust, protective humoral responses are dominated by the production of polyclonal IgA, which binds to polymeric IgA receptors that are universally expressed on ovarian cancer cells. Notably, tumour B-cell-derived IgA redirects myeloid cells against extracellular oncogenic drivers, which causes tumour cell death. In addition, IgA transcytosis through malignant epithelial cells elicits transcriptional changes that antagonize the RAS pathway and sensitize tumour cells to cytolytic killing by T cells, which also contributes to hindering malignant progression. Thus, tumour-antigen-specific and -antigen-independent IgA responses antagonize the growth of ovarian cancer by governing coordinated tumour cell, T cell and B cell responses. These findings provide a platform for identifying targets that are spontaneously recognized by intratumoural B-cell-derived antibodies, and suggest that immunotherapies that augment B cell responses may be more effective than approaches that focus on T cells, particularly for malignancies that are resistant to checkpoint inhibitors.
| S-EPMC7969354 | biostudies-literature
Project description:Although most ovarian cancers show prognostically relevant activated T-cell infiltrates, response rates to immune checkpoint inhibitors are very modest4. Memory B-cell and plasma cell infiltrates have been associated with better outcome in ovarian cancer, but the nature and functional relevance of these responses are controversial. Using 3 independent cohorts totaling 575 high-grade serous ovarian cancer (HGSOC) patients, we show that robust humoral responses are heavily dominated by the production of polyclonal IgA, which binds to Polymeric IgA Receptors universally expressed on ovarian cancer cells. Notably, all tertiary lymphoid structures identified in ~21% of HGSOCs contain IgA-producing oligoclonal B-cells. Strikingly, tumor Bcell-derived IgAs effectively target extracellular oncogenic drivers, whereas IgA transcytosis through malignant epithelial cells elicits transcriptional changes that antagonize the RAS pathway and that sensitize tumor cells to T-cell cytolytic killing, hindering malignant progression. Thus, tumor antigen-specific and antigen-independent IgA responses antagonize ovarian cancer growth by governing coordinated tumor cell, T-cell and B-cell responses. These findings provides a platform for the identification of novel targets spontaneously recognized by intratumoral B-cell-derived antibodies, and suggest that immunotherapies that augment B-cell responses may be more effective than T-cell-centric approaches, particularly for malignancies resistant to checkpoint inhibitors.
2020-12-01 | PXD018079 | Pride
Project description:IgA transcytosis and tumor antigen recognition govern anti-tumor immunity in ovarian cancer
| PRJNA612038 | ENA
Project description:Advances in immunotherapy in the last decade have revolutionized treatment paradigms across multiple cancer diagnoses. However, only a minority of patients derive durable benefit and progress with traditional approaches, such as cancer vaccines, remains unsatisfactory. A key to overcoming these barriers resides with a deeper understanding of tumor antigen presentation and the complex and dynamic heterogeneity of tumor-infiltrating antigen-presenting cells (APCs). Reminiscent of the 'second touch' hypothesis proposed by Klaus Ley for CD4+ T cell differentiation, the acquisition of full effector potential by lymph node- primed CD8+ T cells requires a second round of co-stimulation at the site where the antigen originated, i.e. the tumor bed. The tumor stroma holds a prime role in this process by hosting specialized APC niches, apparently distinct from tertiary lymphoid structures, that support second antigenic touch encounters and CD8+ T cell effector proliferation and differentiation. We propose that APC within second-touch niches become licensed for co-stimulation through stromal-derived instructive signals emulating embryonic or wound-healing provisional matrix remodeling. These immunostimulatory roles of stroma contrast with its widely accepted view as a physical and functional 'immune barrier'. Stromal control of antigen presentation makes evolutionary sense as the host stroma-tumor interface constitutes the prime line of homeostatic 'defense' against the emerging tumor. In this review, we outline how stroma-derived signals and cells regulate tumor antigen presentation and T-cell effector differentiation in the tumor bed. The re-definition of tumor stroma as immune rheostat rather than as inflexible immune barrier harbors significant untapped therapeutic opportunity.
| S-EPMC10754280 | biostudies-literature
Project description:The role of adaptive immunity in early cancer development is controversial. Here we show that chronic inflammation and fibrosis in humans and mice with non-alcoholic fatty liver disease is accompanied by accumulation of liver-resident immunoglobulin-A-producing (IgA+) cells. These cells also express programmed death ligand 1 (PD-L1) and interleukin-10, and directly suppress liver cytotoxic CD8+ T lymphocytes, which prevent emergence of hepatocellular carcinoma and express a limited repertoire of T-cell receptors against tumour-associated antigens. Whereas CD8+ T-cell ablation accelerates hepatocellular carcinoma, genetic or pharmacological interference with IgA+ cell generation attenuates liver carcinogenesis and induces cytotoxic T-lymphocyte-mediated regression of established hepatocellular carcinoma. These findings establish the importance of inflammation-induced suppression of cytotoxic CD8+ T-lymphocyte activation as a tumour-promoting mechanism.
| S-EPMC5884449 | biostudies-literature
Project description:Fatty acid synthase (FASN), the key metabolic enzyme of de novo lipogenesis, provides proliferative and metastatic capacity directly to cancer cells have been described. However, the impact of aberrant activation of this lipogenic enzyme on host anti-tumor immune milieu remains unknown. In this study, we depicted that elevated FASN expression presented in ovarian cancer with more advanced clinical phenotype and correlated with the immunosuppressive status, which characterized by the lower number and dysfunction of infiltrating T cells. Notably, in a mouse model, we showed that tumor cell-intrinsic FASN drove ovarian cancer (OvCa) progression by blunting anti-tumor immunity. Dendritic cells (DCs) are required to initiate and sustain T cell-dependent anti-tumor immunity. Here, our data showed that constitutive activation of FASN in ovarian cancer cell lead to abnormal lipid accumulation and subsequent inhibition of tumor-infiltrating DCs (TIDCs) capacity to support anti-tumor T cells. Mechanistically, FASN activation in ovarian cancer cell-induced the resulting increase of lipids present at high concentrations in the tumor microenvironment. Dendritic cells educated by FASNhigh OvCa ascites are defective in their ability to present antigens and prime T cells. Accordingly, inhibiting FASN by FASN inhibitor can partly restore the immunostimulatory activity of TIDCs and extended tumor control by evoking protective anti-tumor immune responses. Therefore, our data provide a mechanism by which ovarian cancer-intrinsic FASN oncogenic pathway induce the impaired anti-tumor immune response through lipid accumulation in TIDCs and subsequently T-cells exclusion and dysfunction. These results could further indicate that targeting the FASN oncogenic pathway concomitantly enhance anti-tumor immunity, thus offering a unique approach to ovarian cancer immunotherapy.
| S-EPMC6302125 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2022-06-20 | GSE188250 | GEO
Project description:In this Article, the sentence: "After 7 months of HFD, MUP-uPA mice developed HCC15, which contained numerous (usually 50-100 per tumour) non-recurrent coding mutations in pathways that are mutated in human HCC (Fig. 2d and Extended Data Fig. 6a).", should have read: "After 7 months of HFD, MUP-uPA mice developed HCC15, which contained numerous (usually 50-100 per tumour) non-recurrent mutations in pathways that are mutated in human HCC (Fig. 2d and Extended Data Fig. 6a).". This has been corrected online. In Extended Data Fig. 6a and b, which show the number of point mutations identified per sample and the mutational signatures, all sequence variants (including non-coding mutations) are shown. Fig. 2d also presents all variants compared to human mutations. In the Supplementary Information to this Amendment, we now provide the comparisons of all variants and coding variants to human mutations.
| S-EPMC7871211 | biostudies-literature
Project description:Here we describe the clinical and biological activity of guadecitabine, a second generation HMA, given in a low dose as a priming strategy before pembrolizumab, a humanized anti-PD1 antibody in a clinical trial for patients with recurrent, platinum resistant ovarian cancer. The methylomic and transcriptomic effects of the combination demonstrate readily activation of the anti-tumor immunity. High dimensional immune profiling of periferal mononuclear cells (PBMCs) and tumor biopsies obtained before and after treatment show distinct immune profiles and tissue architectural features associated with clinical benefit. Our study provides an in-depth view of the immune milieu of platinum resistant ovarian cancer and of the effects of the combination of HMAs and pembrolizumab on the interactions between immune cell populations and tumor cells.
2022-06-20 | GSE188249 | GEO
Project description:Here we describe the clinical and biological activity of guadecitabine, a second generation HMA, given in a low dose as a priming strategy before pembrolizumab, a humanized anti-PD1 antibody in a clinical trial for patients with recurrent, platinum resistant ovarian cancer. The methylomic and transcriptomic effects of the combination demonstrate readily activation of the anti-tumor immunity. High dimensional immune profiling of periferal mononuclear cells (PBMCs) and tumor biopsies obtained before and after treatment show distinct immune profiles and tissue architectural features associated with clinical benefit. Our study provides an in-depth view of the immune milieu of platinum resistant ovarian cancer and of the effects of the combination of HMAs and pembrolizumab on the interactions between immune cell populations and tumor cells.
2022-06-20 | GSE186825 | GEO