Distinct roles for Blimp-1 in autoreactive CD4 T cells during priming and effector phase of autoimmune encephalomyelitis.

Abstract B lymphocyte-induced maturation protein (Blimp-1) is a transcription factor that regulates effector/memory B cells and CD8 T cells. Here we show that Blimp-1 is expressed in both Th1 and Th17 cells in vitro and highly expressed in effector/memory myelin-specific CD4 T cells in experimental autoimmune encephalomyelitis (EAE) mice. The immunized Blimp-1 conditional knockout mice have a significantly delayed disease onset but enhanced disease severity during the effector phase compared to their wild-type littermates, suggesting that Blimp-1 is a unique transcription factor with distinct roles in the regulation of myelin-specific CD4 T cells during priming and effector phase of EAE. Graphical abstract Unlabelled Image Highlights • Blimp-1 is highly expressed in both Th1 and Th17 cells in vitro and in EAE mice in vivo. • Blimp-1 is highly expressed in effector/memory autoreactive CD4 T cells in EAE mice. • Blimp-1 knockout mice have delayed EAE onset but enhanced EAE severity than WT mice. • More PSGL1hiLy6Clo CD4 Teff cells in Blimp-1 knockout mice than WT littermates. • Blimp-1 is dispensable for IL-23 induced IL-17 production in autoreactive CD4 T cells. [ABSTRACT FROM AUTHOR]