Kruppel-like factor-2 CD4+ T cells and intestinal inflammation

Kruppel 样因子 2 CD4 T 细胞和肠道炎症

• 批准号: 10730990
• 负责人: Sing Sing Way
• 金额: $ 70.59万
• 依托单位: CINCINNATI CHILDRENS HOSP MED CTR
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2027-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10730990
• 关键词: ATAC-seq; Antibodies; Antigens; Autoimmunity; Binding; Biological; Biopsy; Bypass; CD4 Positive T Lymphocytes; CTLA4 gene; Candida albicans; Cell Differentiation process; Cell Lineage; Cells; ChIP-seq; Chromatin; Coculture Techniques; Colitis; Crohn' s disease; Cytoprotection; DNA Binding; Data; Engineering; Enterobacteria phage P1 Cre recombinase; Epigenetic Process; FOXP3 gene; Gene Expression; Gene Expression Profile; Gene Expression Profiling; Gene Silencing; Germ-Free; Homeostasis; House mice; Human; Immune; Immune Tolerance; Immune system; Immunologics; In Vitro; Individual; Inflammation; Inflammatory; Inflammatory Bowel Diseases; Interleukin-10; Intestinal Diseases; Intestines; Irritable Bowel Syndrome; Knowledge; Kruppel-like transcription factors; Link; LoxP-flanked allele; Lymphoid Tissue; MHC Class II Genes; Mediating; Memory; Microbe; Modeling; Molecular; Mucous Membrane; Mus; OX40; Onset of illness; Pathogenesis; Peripheral; Phenotype; Physiological; Production; Property; RNA; Recombinants; Regulatory T-Lymphocyte; Specificity; T cell differentiation; T-Cell Proliferation; T-Lymphocyte; T-Lymphocyte Subsets; Tissues; Ulcerative Colitis; Zinc Fingers; antimicrobial; autoinflammatory diseases; commensal microbes; design; experience; gut colonization; gut inflammation; gut microbiota; in vivo; inducible gene expression; insight; interleukin-10 receptor; mesenteric lymph node; novel; overexpression; reconstitution; response; selective expression; single-cell RNA sequencing; stem

Abstract Mucosal tissues like the intestine harbor trillions of antigenically foreign microbes. Unavoidable approximation with commensal microbes in this context highlights the need for expanded peripheral immune tolerance. However, fundamental gaps in knowledge remain as to how this physiological imperative is achieved. Filling these knowledge gaps have enormous potential to reveal novel insights on the immune- pathogenesis of inflammatory bowel disease and other human autoinflammatory disorders. Our current framework for investigating how tolerance expands to accommodate commensal intestinal microbes is primarily focused on the FOXP3+ suppressive subset of CD4+ T cells called regulatory T cells (Tregs). However, several inconsistencies also highlight the limitations attributing commensal tolerance exclusively to FOXP3+ cells. With these considerations, our preliminary studies pivoted to investigate commensal specific CD4+ T cells, without a FOXP3 bias, using an instructive model whereby CD4+ T cells with commensal specificity can be precisely identified. Using recombinant Candida albicans to establish intestinal colonization and tracking endogenous CD4+ T cells with MHC class II tetramers, our initial analysis of gene expression profiles (single-cell RNA-seq) shows minimal (<5%) Treg differentiation amongst CD4+ cells with commensal specificity. Instead, RNA profiling showed nearly half of peripheral cells that expand in response to commensal stimulation are not classified based on expression of other lineage-defining markers, and unified by expression of the zinc finger transcription factor Kruppel-like factor-2 (KLF2). Antigen-experienced KLF2+ CD4+ T cells are further shown to potently suppress responder T cell proliferation during in vitro co-culture. The necessity for T cell expressed KLF2 is further highlighted by spontaneous intestinal inflammation that develops in mice with conditional KLF2 deficiency in T cells, or the rapid (within 10 days) onset of disease in mice with induced KLF2-deficiency in CD4+ cells. Intestinal inflammation that occurs in the absence of KLF2+ CD4+ T cells is triggered by commensal microbes since their elimination using a cocktail of antimicrobials averts intestinal inflammation, efficiently bypassing the necessity for T cell expressed KLF2. Thus, our overall hypothesis is that KLF2 identifies a FOXP3-negative immune-suppressive subset of CD4+ T cells essential for sustaining tolerance to intestinal microbes. Three inter-related aims designed to further develop this potentially ground- breaking hypothesis are proposed which include establishing the molecular basis for how KLF2+ CD4+ T cells mediate suppression, and whether KLF2 is necessary and/or sufficient to promote functional suppression (Aim 1), the molecular basis for how KLF2+ CD4+ T cells protect against intestinal inflammation in vivo (Aim 2), along with gene expression, chromatin accessibility, and KLF2 DNA binding distinctions between KLF2+ CD4+ T cells compared with FOXP3+ Tregs, and other CD4+ T cell differentiation subsets in intestinal and lymphoid tissue as a basis for their unique biological functional properties (Aim 3).

像肠这样的粘膜组织含有数万亿的抗原性外来微生物。不可避免的