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.
Project description:Tumors express a wide variety of both mutated and non-mutated antigens. Whether these tumor antigens are broadly recognized as “self” or “foreign” 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. Keywords: Transcriptional Profile comparison, context dependent antigen recognition and T Cell differentiation
Project description:Tumor antigen-specific CD4+ T cells are required for the efficacy of immune checkpoint inhibitors in murine models but their contributions in human cancer are less understood. We used targeted single cell RNA sequencing and matching of T cell receptor sequences to identify signatures and functional correlates of tumor antigen-specific CD4+ T cells infiltrating human melanoma tumors. CD4+ T cells that recognize tumor-specific neoantigens express CXCL13 and are subdivided into clusters expressing memory and T follicular helper markers, and those expressing cytolytic markers, exhaustion markers and IFN-. In a cohort of melanoma patients, the frequency of CXCL13+ CD4+ T cells in the tumor correlated with the transcriptional states of CD8+ T cells and macrophages, maturation of B cells, and patient survival. Similar correlations were observed in a breast cancer cohort. These results identify distinct phenotypes and functional correlates of tumor antigen-specific CD4+ T cells in melanoma and suggest the possibility of using such cells to modify the tumor microenvironment.
Project description:The immune system must be able to distinguish self from non-self. During pregnancy, the mother’s immune system does not recognize the placenta as foreign because proteins expressed by tropbholasts, the placental cells that interface with the maternal immune system, do not activate maternal T cells. These activation defects have been previously attributed to suppression by regulatory T cells, while mechanisms of maternal B cell tolerance to trophoblast antigens have not been identified. In this study, we provide evidence that glycan-mediated B cell suppression plays a key role in establishing fetomaternal tolerance in mice. We find that trophoblast antigen-specific B cells are profoundly suppressed via CD22/LYN inhibitory signaling, in turn implicating the antigens’ sialic acids as key suppressive determinants. We also find that B cells mediate the antigen’s MHCII-restricted presentation to CD4 T cells, leading to T cell suppression. The specific goal of the mass spectrometry undertaking deposited here was to identify sialylated “true” placental-derived proteins present in the human and mouse serum proteome during pregnancy. Overall, our findings reveal protein glycosylation as a fundamental feature of placental “self-recognition” and may have relevance to pregnancy complications and tumor immune evasion. Furthermore, we anticipate these findings will enhance synthetic efforts to harness glycans to control antigen-specific immune responses in the treatment of autoimmune diseases.
Project description:CD4 T follicular helper (Tfh) cells provide the required signals to B cells for germinal center reactions that are necessary for longlived antibody responses. However, it remains unclear whether there are CD4+ memory T cells committed to the Tfh lineage after antigen clearance. Using adoptive transfer of antigen-specific memory CD4+ subpopulations (based on CXCR5 and Ly6c expression)in the LCMV infection model, we found that there are distinct memory CD4+ T cell populations with commitment to the Tfh and Th1 lineages. Our conclusions are based on gene expression profiles, epigenetic studies and phenotypic and functional analysis. The gene expression profiles of virus-specific CD4 T cell subets at effector and memory stages is presented here. The SMARTA TCR transgenic / adptive transfer system was used to identify and sort subsets of antigen-specific CD4 T cells (based on their expression of Ly6c and CXCR5) elicited after acute infection with LCMV (Arm).
Project description:CD4+ T cell activation by recognition of Human Leukocyte Antigen II (HLAII)-presented peptides is a key step in the development of unwanted immunogenicity against biotherapeutics
Project description:The gut epithelium is populated by intraepithelial lymphocytes (IELs), a heterogeneous T cell population with cytotoxic and regulatory properties, which can be imprinted on CD4+ T cells at the epithelium. However, the role of the T cell receptor (TCR) in this process remains unclear. Single-cell transcriptomic analyses revealed distinct clonal expansions between cell states, with CD4-IELs being one of the least diverse populations. Conditional deletion of TCR on differentiating CD4+ T cells or of MHCII on intestinal epithelial cells prevented CD4-IEL differentiation. However, TCR ablation on differentiated CD4-IELs, or long-term cognate antigen withdraw, did not affect their maintenance. TCR re-engaging of antigen-specific CD4-IELs during Listeria monocytogenes infection did not alter their state but correlated with reduced bacteria invasion. Thus, local antigen recognition is an essential signal for differentiation of T cells at the epithelium but differentiated CD4-IELs are able to preserve an effector program in the absence of TCR signaling.
Project description:CD4 T follicular helper (Tfh) cells provide the required signals to B cells for germinal center reactions that are necessary for longlived antibody responses. However, it remains unclear whether there are CD4+ memory T cells committed to the Tfh lineage after antigen clearance. Using adoptive transfer of antigen-specific memory CD4+ subpopulations (based on CXCR5 and Ly6c expression)in the LCMV infection model, we found that there are distinct memory CD4+ T cell populations with commitment to the Tfh and Th1 lineages. Our conclusions are based on gene expression profiles, epigenetic studies and phenotypic and functional analysis. The gene expression profiles of virus-specific CD4 T cell subets at effector and memory stages is presented here.
Project description:The purpose of this study was to conduct an in-depth analysis of the molecular characteristics of both CD4 and CD8 T cells upon encounter of self-associated antigen bound to erythrocytes, induce therapeutic tolerance in an endogenous repertoire of T cells, and understand the mechanisms involved in uptake and presentation of erythrocyte-associated antigen.