RT Journal Article SR Electronic T1 Differentiating MHC-Dependent and -Independent Mechanisms of Lymph Node Stromal Cell Regulation of Proinsulin-Specific CD8+ T-Cells in type 1 Diabetes JF Diabetes JO Diabetes FD American Diabetes Association SP db191050 DO 10.2337/db19-1050 A1 Thayer, Terri C. A1 Davies, Joanne A1 Pearson, James A. A1 Hanna, Stephanie J. A1 Wen, Li A1 Wong, F. Susan YR 2020 UL http://diabetes.diabetesjournals.org/content/early/2020/10/28/db19-1050.abstract AB Lymph node stromal cells (LNSC) are essential for providing and maintaining peripheral self-tolerance of potentially autoreactive cells. In type 1 diabetes, proinsulin-specific CD8+T-cells, escaping central and peripheral tolerance, contribute to beta-cell destruction. Using G9Cα-/-CD8+T-cells specific for proinsulin, we studied the mechanisms by which LNSC regulate low-avidity autoreactive cells in the nonobese diabetic (NOD) mouse model of type 1 diabetes. Whereas MHC-matched NOD-LNSC significantly reduced G9Cα-/-CD8+T-cell cytotoxicity and DC-induced proliferation, they failed to sufficiently regulate T-cells stimulated by anti-CD3/CD28. In contrast, non-MHC matched, control C57BL/6 mouse LNSC suppressed T-cell receptor engagement by anti-CD3/CD28 via MHC-independent mechanisms. This C57BL/6-LNSC suppression was maintained even after removal of the LNSC, demonstrating a direct effect of LNSC on T-cells, modifying antigen sensitivity and effector function. Thus, our results suggest that a loss of NOD-LNSC MHC-independent suppressive mechanisms may contribute to diabetes development.