# Kruppel-like factor-2 CD4+ T cells and intestinal inflammation > **NIH NIH R01** · CINCINNATI CHILDRENS HOSP MED CTR · 2024 · $695,424 ## Abstract 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 ce... ## Key facts - **NIH application ID:** 10914269 - **Project number:** 5R01AI172960-02 - **Recipient organization:** CINCINNATI CHILDRENS HOSP MED CTR - **Principal Investigator:** Sing Sing Way - **Activity code:** R01 (R01, R21, SBIR, etc.) - **Funding institute:** NIH - **Fiscal year:** 2024 - **Award amount:** $695,424 - **Award type:** 5 - **Project period:** 2023-09-01 → 2027-08-31 ## Primary source NIH RePORTER: https://reporter.nih.gov/project-details/10914269 ## Citation > US National Institutes of Health, RePORTER application 10914269, Kruppel-like factor-2 CD4+ T cells and intestinal inflammation (5R01AI172960-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10914269. Licensed CC0. --- *[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*