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Project Abstracts - CMAI

HLA multimer based characterization of Islet Resident CD4+ T Cells that Target Beta Cell Epitopes and Neo-epitopes

Contact PI: Eddie James, PhD

Abstract

This project seeks to robustly characterize islet resident T cells that target beta cell epitopes.  Our work will examine T cell specificities that are represented in the most disease relevant tissue, utilizing T cell lines isolated from the isolated islets of five autoantibody positive donors who had not yet developed T1D.  In the autoantibody positive “pre-diabetes” setting we anticipate that infiltrating T cells could exhibit either an inflammatory effector phenotype that promotes autoimmunity or a regulatory phenotype that restrains autoimmunity. Documenting either of these phenomena would be of great interest.  Our experimental strategy will initially focus on HLA tetramer staining and flow cytometry analysis of these cell lines.  We anticipate that we can isolate and expand multiple tetramer positive T cell clones from each of the expanded cell lines but we will also apply complementary assays to identify, sort, and isolate T cells that recognize alternative beta cell specificities.  The resulting clones will be subjected to functional analysis to assess their relative polarization.  A subset of these cells will also be subjected to TCR sequence analysis.  We expect this work will demonstrate that T cells that recognize post-translationally modified epitopes are present among cells that infiltrate islets prior to disease onset, allowing us to draw inferences about role that these cells might have played in either promoting or regulating beta cell autoimmunity in these subjects.