Abstract B167: Antigen-presenting cells as coordinators of T-cell responses to gut microbiota

Abstract

Abstract The immune system in the gut mucosa must balance tolerance to harmless diet and microbial antigens with the ability to mount effective inflammatory responses to diverse invasive pathogens. These requirements are reflected in the functions of distinct subsets of T-cells whose differentiation is guided by diverse cytokines secreted by antigen-presenting cells (APCs). In recent years, different APCs subsets have been proposed to guide CD4+ T-cell polarization and to induce primary T-cell responses in lymph nodes versus secondary responses in tissues. However, the exact roles of APC subsets in mediating T-cell responses to gut microbiota are still under debate and have not been thoroughly addressed. We previously showed that the commensal microbe segmented filamentous bacteria (SFB) induces antigen-specific Th17 cells, while Helicobacter hepaticus (Hh) induces an antigen-specific Treg response. Using those microbial models, I am now studying the contribution of APC subsets to specific T-cell response. I utilize several different approaches to track APC subsets that presents the relevant microbial peptides in the mesenteric lymph node and to characterize their contribution to T-cell priming and polarization. A better understanding of which APCs participate in the differentiation of each category of T-cell will enable in the future to develop better tools to educate T-cells to fight cancer. Citation Format: Ranit Kedmi, Kai Mesa, Dan Littman. Antigen-presenting cells as coordinators of T-cell responses to gut microbiota [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B167.