Intravenous transfer of LPS-treated bone marrow-derived dendritic cells blocks development of autoimmunity induced by CD4+ T cells in vivo. However, cellular mechanisms of dendritic cell-mediated immune tolerance have not yet been fully elucidated. Here, we report that there are two new subpopulations of CD4+CD25+FoxP3+GITR+ regulatory T cells (CD127+3G11+ and CD127+3G11- cells). LPS-treated dendritic cells facilitate development of CD4+CD127+3G11- regulatory T cells but inhibit that of CD4+CD127+3G11+ regulatory T cells. LPS-induced tolerogenic dendritic cells may cause immune tolerance through modulating balance of different subsets of CD4+ regulatory T cells mediated by CD127 and 3G11. Our results imply a new potential cellular mechanism of dendritic cell-mediated immune tolerance.