Capicua deficiency induces autoimmunity and promotes follicular helper T cell differentiation via derepression of ETV5.

Park, Sungjun; Lee, Seungwon; Lee, Choong-Gu; Park, Guk Yeol; Hong, Hyebeen; Lee, Jeon-Soo; Kim, Young Min; Lee, Sung Bae et al. · Nat Commun · 2017

basic_science · Level V

Where this comes from

Abstract

High-affinity antibody production through the germinal centre (GC) response is a pivotal process in adaptive immunity. Abnormal development of follicular helper T (T<sub>FH</sub>) cells can induce the GC response to self-antigens, subsequently leading to autoimmunity. Here we show the transcriptional repressor Capicua/CIC maintains peripheral immune tolerance by suppressing aberrant activation of adaptive immunity. CIC deficiency induces excessive development of T<sub>FH</sub> cells and GC responses in a T-cell-intrinsic manner. ETV5 expression is derepressed in Cic null T<sub>FH</sub> cells and knockdown of Etv5 suppresses the enhanced T<sub>FH</sub> cell differentiation in Cic-deficient CD4<sup>+</sup> T cells, suggesting that Etv5 is a critical CIC target gene in T<sub>FH</sub> cell differentiation. Furthermore, we identify Maf as a downstream target of the CIC-ETV5 axis in this process. These data demonstrate that CIC maintains T-cell homeostasis and negatively regulates T<sub>FH</sub> cell development and autoimmunity.

Medical subject headings