IL17A and colitis: Consistently, CD11chiCD45RB− conventional DCs exhibited partial protection against the induction of colitis by CD4+ CD25− T cells (Fig. 5), even though these conventional DCs significantly augmented IFN-γ and IL-17A expression in activated CD4+ T cells (Fig. 3A,B) and slightly enhanced the antigen-nonspecific proliferation of CD4+ T cells (Fig. 3D) in vitro.