PRDM1 and Autoimmunity: Consistent with the finding that IL-12 is an important driver of Blimp-1-dependent Tr1 cell differentiation in autoimmunity [52], we found that Blimp-1 and IL-10 expression by IFNγ-producing CD4+ T cells from L. donovani-infected mice required IL-12 (Fig 2D and 2E).