MHC class II peptides induce CD8 + CD44 + Ly49 + regulatory T cells in C57BL/6 mice.

CD8+ regulatory T cells (Tregs) play an important role in regulating peripheral immune tolerance. However, difficulties in the characterization of CD8+ Tregs that lack suitable markers have a considerably limited research in this area. Moreover, the induction and effector mechanisms of CD8+ Tregs remain unclear. Herein, we demonstrate the suitability of Ly49 and CD44 as markers for CD8+ Tregs. Our data also show that MHC class II restricted peptides induce CD8+ CD44+ Ly49+ Tregs via CD4+ T cell activation. Furthermore, we also found cross-suppressive activity of these CD8+ Tregs on responding CD4+ T cells in a cytotoxicity dependent manner. Our data provide new insights into the induction and function of CD8+ Tregs.