biostudies-literatureXu LGNIAID NIH HHS248-58https://www.ebi.ac.uk/biostudies/studies/S-EPMC3244560biostudies-literatureUnknown188(1)B cells play a critical role in the initialization and development of the systemic lupus erythematosus that is dependent on the expression of the endosomal ssRNA receptor TLR7. Previous studies have established that B cell expression of TLR7 is controlled by the type I IFN secreted by plasmacytoid dendritic cells. In this article, we report that VISA, also known as MAVS, IPS-1, and CardIf, essential for RIG-I/MDA5-mediated signaling following sensing of cytosolic RNA, regulate B cell expression of TLR7 and CD23. We found that B cells from a VISA(-/-) mouse express reduced TLR7 but normal basal levels of type I IFN. We also show that although IFN-β and TLR7 agonists synergize to promote TLR7 expression in VISA(-/-) B cells, they do not fully complement the defect seen in VISA(-/-) cells. CeJournal of immunology (Baltimore, Md. : 1950)VISA is required for B cell expression of TLR7.PMC3244560P01 AI022295P01AI022295022P01 AI022295-22R01 AI062739-05S1R01 AI062739-05S2R01 AI062739-05R01 AI062739R01AI062739-05R01AI062739-05S2R01AI062739-05S1Zhang BCXu LGAkerlund LJShu HBJin LCambier JCfalseVISA is required for B cell expression of TLR7.B cells play a critical role in the initialization and development of the systemic lupus erythematosus that is dependent on the expression of the endosomal ssRNA receptor TLR7. Previous studies have established that B cell expression of TLR7 is controlled by the type I IFN secreted by plasmacytoid dendritic cells. In this article, we report that VISA, also known as MAVS, IPS-1, and CardIf, essential for RIG-I/MDA5-mediated signaling following sensing of cytosolic RNA, regulate B cell expression of TLR7 and CD23. We found that B cells from a VISA(-/-) mouse express reduced TLR7 but normal basal levels of type I IFN. We also show that although IFN-β and TLR7 agonists synergize to promote TLR7 expression in VISA(-/-) B cells, they do not fully complement the defect seen in VISA(-/-) cells. Ce2012-01-01T00:00:00Z2012 Jan2025-04-18T17:24:39.376Z2019-03-26T23:42:55ZS-EPMC32445602210599410.4049/jimmunol.1100918