Cancer and germline exomes, and cancer RNA-seq consisiting of FASTQ paired-end reads from melanoma, lung and colon cancer samples
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ABSTRACT:
PROVIDER: EGAS00001005513 | EGA |
REPOSITORIES: EGA
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Project description:Microbial organisms play key roles in numerous physiological processes in the human body and have recently been shown to modify the response to cancer radiotherapy and immune checkpoint inhibitors. Here, we demonstrate that HLA molecules of both glioblastoma tissues as well as tumor cell lines present bacteria-specific peptides. This finding prompted us to examine whether tumor-infiltrating lymphocytes (TILs) recognize intratumoral microbiota. Indeed, bacterial peptides eluted from HLA-DR II molecules are recognized by both TILs, albeit weakly, and peripheral blood-derived memory CD4+ T cells, which, upon stimulation with bacterial peptides, also recognize several tumor antigens. Furthermore, using an unbiased antigen discovery approach for a TIL CD4+ T cell clone (TCC) we show that it recognizes a broad spectrum of peptides from pathogenic bacteria, commensal gut microbiota and also glioblastoma-related tumor antigens. These peptides were strongly stimulatory for bulk TILs and peripheral blood memory cells. Our data hint at how bacterial pathogens and bacterial gut microbiota can be involved in specific immune recognition of tumor antigens.
2023-02-20 | PXD036811 | Pride
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2023-09-07 | PXD035344 | Pride
Project description:Cross-presentation of exogenous antigens in HLA-class I molecules by professional antigen presenting cells (APCs) is crucial for CD8+ T cell function. Recent murine studies show that several non-professional APCs, including cancer-associated fibroblasts (CAFs) also possess this capacity. It is currently unknown whether human CAFs are able to cross-present exogenous antigen, which molecular pathways are involved in this process and how this ultimately affects tumor-specific CD8+ T cell function. Here we show that human colorectal cancer (CRC)-derived CAFs display an enhanced capacity to cross-present neoantigen-derived synthetic long peptides (SLPs) when compared to normal colonic fibroblasts. Importantly, cross-presentation of antigens required the lysosomal protease Cathepsin S. Cathepsin S expression by CAFs was detected in situ in human CRC tissue, was upregulated in ex vivo cultured CRC-derived CAFs and showed increased expression in normal fibroblasts after exposure to CRC-conditioned medium. Cognate interaction between CD8+ T cells and cross-presenting CAFs suppressed T cell function, reflected by decreased cytotoxicity, reduced activation (CD25, CD137) and increased exhaustion (TIM3) marker expression. Our data indicate that CAFs may directly suppress tumor-specific T cell function in an antigen-dependent fashion in human CRC.
2022-03-03 | PXD029507 | Pride
Project description:Tumors express a wide variety of both mutated and non-mutated antigens. Whether these tumor antigens are broadly recognized as âselfâ or âforeignâ by the immune system is currently unclear. Using an autochthonous prostate cancer model in which hemagglutinin (HA) is specifically expressed in the tumor (ProHA x TRAMP mice), as well as an analogous model wherein HA is expressed in normal tissues as a model self-antigen (C3HAHigh), we examined the transcriptional profile of CD4 T cells undergoing antigen-specific division. Consistent with our previous data, transfer of antigen-specific CD4 T cells into C3HAHigh resulted in a functionally inactivated CD4 T cell profile. Conversely, adoptive transfer of an identical CD4 T cell population into ProHA x TRAMP resulted in the induction of a regulatory phenotype (Treg) both at the transcriptional and functional level. Interestingly, this Treg skewing was a property of even early-stage tumors, suggesting Treg induction as an important tolerance mechanism during tumor development. The goal of this microarray is to detail the transcriptional profile differences between CD4 T cells that recognize their cognate antigen in the context of tumor (ProHA x TRAMP model) or self-antigen recognition (C3HA) or viral-antigen recognition (VaccHA) models or unprimed naïve state (Nontransgenic). The comparison contains both upregulated and downregulated transcripts. Experiment Overall Design: TCR transgenic CD4 T cells specific for hemagglutinin (HA) were adoptively transferred into tumor-antigen recognition model (ProHA x TRAMP), Self-antigen recognition model (C3HA), viral-antigen recognition model (VaccHA), and naïve control (Nontrangenic). Divided (CFSE diluted) CD4 T cells were sorted by FACS, RNA was extracted, and biological replicated were hybridized to an Affymetrix Mouse 430 Plus 2 expression array, followed by interrogation with an Affymetrix GeneChip Scanner 3000. RMA normalization was employed to identify differentially expressed transcripts.
2009-02-08 | E-GEOD-14662 | biostudies-arrayexpress
Project description:This model of the immune system response to antigen presentation is based on the publication:
Eduardo D.Sontag (2017) 'A Dynamic Model of Immune Responses to Antigen Presentation Predicts Different Regions of Tumor or Pathogen Elimination', Cell Systems, 4(2)
DOI: 10.1016/j.cels.2016.12.003
Comment:
This model is based on the "toy model" as described by Equations 1A-1C from the manuscript and the system represented by Equation 2, which exhibits a type of incoherent feedforward loop (IFFL).
Abstract:
The immune system must discriminate between agents of disease and an organism’s healthy cells. While the identification of an antigen as self/non-self is critically important, the dynamic features of antigen presentation may also determine the immune system’s response. Here, we use a simple mathematical model of immune activation to explore the idea of antigen discrimination through dynamics. We propose that antigen presentation is coupled to two nodes, one regulatory and one effecting the immune response, through an incoherent feedforward loop and repressive feedback. This circuit would allow the immune system to effectively estimate the increase of antigens with respect to time, a key determinant of immune reactivity in vivo. Our model makes the prediction that tumors growing at specific rates evade the immune system despite the continuous presence of antigens indicating disease, a phenomenon closely related to clinically observed “two-zone tolerance.” Finally, we discuss a plausible biological instantiation of our circuit using combinations of regulatory and effector T cells.
2021-08-16 | BIOMD0000001030 | BioModels
Project description:Introduction: Despite predicted efficacy, immunotherapy in epithelial ovarian cancer (EOC) has limited clinical benefit and the prognosis of patients remains poor. There is thus a strong need for better identifying local immune dynamics and immune-suppressive pathways limiting T-cell mediated anti-tumor immunity. Methods: In this observational study we analyzed by immunohistochemistry, gene expression profiling and flow cytometry the antigenic landscape and immune composition of 48 EOC specimens, with a focus on tumor-infiltrating lymphocytes (TILs). Results: Activated T cells showing features of partial exhaustion with a CD137+CD39+PD-1+TIM-3+CD45RA-CD62L-CD95+ surface profile were exclusively present in EOC specimens but not in corresponding peripheral blood or ascitic fluid, indicating that the tumor microenvironment might sustain this peculiar phenotype. Interestingly, while neoplastic cells expressed several tumor-associated antigens possibly able to stimulate tumor-specific TILs, macrophages provided both co-stimulatory and inhibitory signals and were more abundant in TILs-enriched specimens harboring the CD137+CD39+PD-1+TIM-3+CD45RA-CD62L-CD95+ signature. Conclusions: These data demonstrate that EOC is enriched in CD137+CD39+PD-1+TIM-3+CD45RA-CD62L-CD95+ T lymphocytes, a phenotype possibly modulated by antigen recognition on neoplastic cells and by a combination of inhibitory and co-stimulatory signals largely provided by infiltrating myeloid cells. Furthermore, we have identified immunosuppressive pathways potentially hampering local immunity which might be targeted by immunotherapeutic approaches
2023-10-02 | GSE243751 | GEO
Project description:Cellular senescence is a stress response that activates innate immunity. However, the interplay between senescent cells and the adaptive immune system remains largely unexplored. Here, we show that senescent cells display enhanced MHC class I (MHC-I) antigen processing and presentation. Immunization of mice with senescent syngeneic fibroblasts generates CD8 T cells reactive against both normal and senescent fibroblasts, some of them targeting senescence-associated MHC-I-peptides. In the context of cancer, we demonstrate that senescent cancer cells trigger strong anti-tumor protection mediated by antigen-presenting cells and CD8 T cells. This response is superior to the protection elicited by cells undergoing immunogenic cell death. Finally, induction of senescence in patient-derived cancer cells exacerbates the activation of autologous tumor-reactive CD8 tumor-infiltrating lymphocytes (TILs) with no effect on non-reactive TILs. Our study indicates that immunization with senescent cancer cells strongly activates anti-tumor immunity, and this can be exploited for cancer therapy.
2022-11-09 | PXD034059 | Pride
Project description:Colorectal cancer is the second leading cause of cancer death worldwide, and the incidence of this disease is expected to increase as global socioeconomic changes occur. Immune checkpoint inhibition therapy is effective in treating a minority of colorectal cancer tumors; however, microsatellite stable tumors do not respond well to this treatment. Emerging cancer immunotherapeutic strategies aim to activate a cytotoxic T cell response against tumor-specific antigens, presented exclusively at the cell surface of cancer cells. These antigens are rare and are most effectively identified with a mass spectrometry-based approach, which allows the direct sampling and sequencing of these peptides. While the few tumor-specific antigens identified to date derived from coding regions of the genome, recent findings indicate that a large proportion of tumor-specific antigens originate from allegedly noncoding regions. Here, we employed a novel proteogenomic approach to identify tumor antigens in a collection of colorectal cancer-derived cell lines and biopsy samples consisting of matched tumor and normal adjacent tissue. The generation of personalized cancer databases paired with mass spectrometry analyses permitted the identification of more than 30 000 unique MHC I-associated peptides. We identified 19 putative tumor-specific antigens in both microsatellite stable and unstable tumors, over two-thirds of which were derived from non-coding regions. Many of these peptides were derived from source genes known to be involved in colorectal cancer progression, suggesting that antigens from these genes could have therapeutic potential in a wide range of tumors. These findings could benefit the development of T cell-based vaccines, in which T cells are primed against these antigens to target and eradicate tumors. Such a vaccine could be used in tandem with existing immune checkpoint inhibition therapies, to bridge the gap in treatment efficacy across subtypes of colorectal cancer with varying prognoses.
2022-04-13 | PXD028309 | Pride
Project description:Immunotherapy directed against private tumor neo-antigens derived from non-synonymous somatic mutations is a promising strategy of personalized cancer immunotherapy. However, feasibility in low mutational load tumor types remains unknown. Comprehensive and deep analysis of circulating and tumor-infiltrating lymphocytes (TILs) for neo-epitope specific CD8 + T cells allowed prompt identification of oligoclonal and polyfunctional such cells from most immunotherapy-naïve patients with advanced epithelial ovarian cancer studied. Neo-epitope recognition was discordant between circulating T cells and TILs, and was more likely to be found among TILs, which displayed higher functionalavidity and unique TCRs with higher predicted affinity than their blood counterparts. Our results imply that identification of neo-epitope specific CD8 + T cells is achievable even in tumors with relatively low number of somatic mutations, and neo-epitope validation in TILs extends opportunities for mutanome-based personalized immunotherapies to such tumors.
| EGAS00001002803 | EGA