C1q/TNF-related protein 4 (CTRP4) is generally thought to be released extracellularly and plays a critical role in energy metabolism and protecting against sepsis. However, its physiological functions in autoimmune diseases have not been thoroughly explored. In this study, we demonstrate that Th17 cell–associated experimental autoimmune encephalomyelitis was greatly exacerbated in Ctrp4–/– mice compared with WT mice due to increased Th17 cell infiltration. The absence of Ctrp4 promoted the differentiation of naive CD4+ T cells into Th17 cells in vitro. Mechanistically, CTRP4 interfered with the interaction between IL-6 and the IL-6 receptor (IL-6R) by directly competing to bind with IL-6R, leading to suppression of IL-6–induced activation of the STAT3 pathway. Furthermore, the administration of recombinant CTRP4 protein ameliorated disease symptoms. In conclusion, our results indicate that CTRP4, as an endogenous regulator of the IL-6 receptor–signaling pathway, may be a potential therapeutic intervention for Th17-driven autoimmune diseases.
Lulu Cao, Jinhai Deng, Wei Chen, Minwei He, Ning Zhao, He Huang, Lu Ling, Qi Li, Xiaoxin Zhu, Lu Wang