Poly IC pretreatment suppresses B cell-mediated lupus-like autoimmunity through induction of Peli1.

Noncanonical NF-κB pathway is essential for the B cell activation and antibody production, which centralize the critical role of B cells in regulating the pathogenesis of systemic lupus erythematosus (SLE). We have previously demonstrated that Pellino1 (Peli1) negatively regulates noncanonical NF-κB activation and lupus autoimmunity. Here, we showed that poly IC is a potent inducer of Peli1 protein in mouse splenic B cells in dose- and time-dependent manners, and poly IC-induced Peli1 protein dramatically suppressed the activation of noncanonical NF-κB pathway. In addition, poly IC-pretreated B cells failed to induce lupus-like disease in BM12 CD4+ T cell-immunized mice. Accordingly, the induction of antibody-producing plasma cells and germinal center B cells, as well as the production of autoantibodies were significantly impaired in immunized μMT mice that were transferred with poly IC-pretreated B cells. Our findings demonstrate that poly IC-induced Peli1 negatively regulates the noncanonical NF-κB pathway in the context of restraining the pathogenesis of lupus-like disease.