Non-coding autoimmune risk variant accelerates T peripheral helper cell development via ICOS
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ABSTRACT:
PROVIDER: PRJNA987728 | ENA |
REPOSITORIES: ENA
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Project description:Fine-mapping and functional studies implicate rs117701653, a common non-coding variant in the CD28/CTLA4/ICOS locus, as a contributor to risk for rheumatoid arthritis and type 1 diabetes. Using DNA pulldown, mass spectrometry, genome editing and eQTL analysis, we establish that the disease-associated allele reduces affinity for the inhibitory chromosomal regulator SMCHD1 to drive expression of inducible T-cell costimulator (ICOS), enhancing memory CD4+ T cell ICOS expression in individuals bearing the risk allele. Higher ICOS expression is paralleled by an increase in circulating T peripheral helper (Tph) cells, and in rheumatoid arthritis patients, of blood and joint fluid Tph cells and circulating plasmablasts, suggesting a causal link. Indeed, ICOS ligation accelerates T cell differentiation into CXCR5-PD-1high Tph cells producing IL-21 and CXCL13, as does carriage of the rs117701653 risk allele. Thus, mechanistic dissection of a causal non-coding variant in human autoimmunity discloses a new pathway through which ICOS regulates Tph abundance.
2023-07-01 | GSE235868 | GEO
Project description:Our fine-mapping of 76 non-MHC loci associated with risk for rheumatoid arthritis (RA, 11,475 cases, 15,870 controls) has recently identified rs117701653, a non-coding single nucleotide polymorphism (SNP) in the CTLA4/CD28/ICOS locus, as the variant most likely to modulate RA risk within this region, with the minor allele (C) showing disease protection compared to the major allele (A). Notably, this SNP exhibits allele-specific protein binding, further supporting its regulatory nature, including greater binding of proteins from Jurkat T cell nuclear extract to the protective allele (C) than to the risk allele (A) by electrophoretic mobility shift assay (EMSA). To identify this protein or protein complex, we applied an efficient DNA pulldown technique, flanking restriction enhanced pulldown (FREP), using nuclear extract from Jurkat T cells, bait DNA corresponding to the (C) allele of rs117701653, competitor DNA fragment, and irrelevant DNA sequence as a negative control. Mass spectrometry analysis of peptides released from FREP identified 43 proteins. Our strongest candidate was structural maintenance of chromosomes flexible hinge domain-containing protein 1 (SMCHD1), which exhibited specific binding to the (C) allele of rs117701653. We confirmed the allelic affinity of SMCHD1 using multiple orthogonal approaches, including FREP and western blotting, EMSA with anti-SMCHD1 antibodies, and CHIP-qPCR with CRISPR-modified Jurkat clones bearing different genotype at rs117701653. In this study, we identified SMCHD1, a chromatin regulator that binds allelically to the rs117701653 allele (C) associated with protection against RA risk.
2024-05-23 | PXD048977 | Pride
Project description: Not available
| S-EPMC10923805 | biostudies-literature
Project description:T follicular helper (Tfh) cells constitute an essential cell type in the induction of antibodies. We report that CD4 T cells lacking Foxo1 almost uniformly became CXCR5int Tfh cells following immunization. Moreover, a Foxo1 loss-of-function complemented an Icos mutation allowing the appearance of Tfh cells along with follicular, class-switched B cells and IgG isotype anti-DNA antibodies. Similarly, FOXO1 deficient Tfh differentiation displayed a substantially reduced dependence on ICOSL. Functional and molecular analyses show that FOXO1 regulates Tfh differentiation through a broad program of gene expression exemplified by positive regulation of Icos and negative regulation of Bcl6. These results demonstrate that a key step in Tfh differentiation is the ICOS-initiated activation of the PI3K-AKT pathway resulting in the inactivation of FOXO1. Performed ChIP-seq analysis to examine the role of foxo1 in the development of Tfh cells
2013-06-01 | E-GEOD-46525 | biostudies-arrayexpress
Project description:The maintenance of the TFH phenotype depends on continuous signals via ICOS. For a global assessment of differences in gene expression after interruption of the ICOS pathway a genome wide transcriptome analysis was performed. We used the OT-II adoptive transfer system to isolate antigen-specific TFH cells (day 6 after immunization) after short-term (6 hours) blockade of the ICOS pathway using a monoclonal antibody against ICOS-L. Gene expression profiles of TFH cells with or without ICOS-L blockade. Affymetrix MG 430 2.0 whole genome arrays were performed in duplicates for the control and blockade group (4 arrays in total). To obtain genes significantly regulated upon ICOS L blockade, the expression profiles of TFH cells treated with an isotype control or anti-ICOS-L antibody were compared to each other. After total RNA extraction, reverse transcription, cDNA extraction, the biotinylated cRNA was transcribed, fragmented, and 15 M-BM-5g cRNA hybridized in duplicates for each of the two groups to the 4 GeneChip arrays: Group1 TFH cells control, Group2 TFH cells ICOS-L blockade.
2015-01-19 | E-GEOD-49314 | biostudies-arrayexpress
Project description:The maintenance of the TFH phenotype depends on continuous signals via ICOS. For a global assessment of differences in gene expression after interruption of the ICOS pathway a genome wide transcriptome analysis was performed. We used the OT-II adoptive transfer system to isolate antigen-specific TFH cells (day 6 after immunization) after short-term (6 hours) blockade of the ICOS pathway using a monoclonal antibody against ICOS-L.
2015-01-19 | GSE49314 | GEO
Project description:Interaction of ICOS - ICOS ligand is required for the germinal center formation, T-cell immune responses, and development of autoimmune diseases. Human ICOS deficiency with the identical ICOS mutation has been identified in nine patients worldwide. In vitro studies showed T-cell defect of the patients was mild, and in vivo autoimmunity was uncommon and mild. Here we report in-depth analysis of T-cell function in two siblings with novel ICOS deficiency. While the brother displayed mild skin infections, psoriasis-like skin region, and defective immunoglobulin class switching, the sister had more severe symptoms, which included immunodeficiency, rheumatoid arthritis, inflammatory bowel disease, interstitial pneumonitis, and psoriasis. Despite of normal CD3/CD28-induced proliferation and IL-2 production in vitro, peripheral blood T-cells from both patients demonstrated decreased percentage of CD4 central and effector memory T-cells and impaired production of Th1, Th2, and Th17 cytokines upon CD3/CD28 costimulation or upon PMA/ionophore stimulation. The defective polarization into effector cells were associated with impaired induction of T-bet, GATA3 and MAF and RORC. Reduced CTLA-4+CD45RO+ FoxP3+ regulatory T-cells and diminished induction of inhibitory cell surface molecules including CTLA-4 were also observed in the patients. Further analysis of the gene expression and immune functions of the patients demonstrated increased induction of RANKL, lack of IFN-g response, and loss of Itch expression upon activation in the female case with autoimmunity. Our study suggests extensive T-cell dysfunction and loss of balance between effector cells and regulatory cells in the ICOS-deficient patients may account for their immunodeficiency and/or autoimmune disorder.
2008-09-26 | GSE12875 | GEO
Project description:ICOS (Inducible Costimulator) is a T cell costimulatory molecule. We found that the cloned T-cell hybridoma 6-13-64 consists of two populations, ICOS expressing and non-expressing. The aim of this study is to screen for candidate genes that regulate ICOS gene expression by transcriptional profiling and comparison of the ICOS-positive and ICOS-negative subpopulations isolated from the 6-13-64 T-cell hybridoma. One-condition experiment, ICOS(-) vs. ICOS(+) cells. Independently grown and harvested. One replicate per array.
2012-03-31 | E-GEOD-20922 | biostudies-arrayexpress
Project description:T follicular helper (Tfh) cells are essential in the induction of high-affinity, class-switched antibodies. The differentiation of Tfh cells is a multi-step process that depends upon the co-receptor ICOS and the activation of phosphoinositide-3 kinase leading to the expression of key Tfh cell genes. We report that ICOS signaling inactivates the transcription factor FOXO1, and a Foxo1 genetic deletion allowed for generation of Tfh cells with reduced dependence on ICOS ligand. Conversely, enforced nuclear localization of FOXO1 inhibited Tfh cell development even though ICOS was overexpressed. FOXO1 regulated Tfh cell differentiation through a broad program of gene expression exemplified by its negative regulation of Bcl6. Final differentiation to germinal center Tfh cells (GC-Tfh) was instead FOXO1 dependent as the Foxo1(-/-) GC-Tfh cell population was substantially reduced. We propose that ICOS signaling transiently inactivates FOXO1 to initiate a Tfh cell contingency that is completed in a FOXO1-dependent manner.
2015-01-01 | GSE46525 | GEO
Project description:ICOS (Inducible Costimulator) is a T cell costimulatory molecule. We found that the cloned T-cell hybridoma 6-13-64 consists of two populations, ICOS expressing and non-expressing. The aim of this study is to screen for candidate genes that regulate ICOS gene expression by transcriptional profiling and comparison of the ICOS-positive and ICOS-negative subpopulations isolated from the 6-13-64 T-cell hybridoma.
2012-04-01 | GSE20922 | GEO