Nagasu, AkikoMukai, TomoyukiIseki, MasanoriKawahara, KyokoTsuji, ShokoNagasu, HajimeUeki, YasuyoshiIshihara, KatsuhikoKashihara, NaokiMorita, Yoshitaka2019-08-282019-08-282019-04-30Nagasu, A., Mukai, T., Iseki, M., Kawahara, K., Tsuji, S., Nagasu, H., … Morita, Y. (2019). Sh3bp2 Gain-Of-Function Mutation Ameliorates Lupus Phenotypes in B6.MRL-Faslpr Mice. Cells, 8(5), 402. doi:10.3390/cells8050402https://hdl.handle.net/1805/20671SH3 domain-binding protein 2 (SH3BP2) is an adaptor protein that is predominantly expressed in immune cells, and it regulates intracellular signaling. We had previously reported that a gain-of-function mutation in SH3BP2 exacerbates inflammation and bone loss in murine arthritis models. Here, we explored the involvement of SH3BP2 in a lupus model. Sh3bp2 gain-of-function (P416R knock-in; Sh3bp2KI/+) mice and lupus-prone B6.MRL-Faslpr mice were crossed to yield double-mutant (Sh3bp2KI/+Faslpr/lpr) mice. We monitored survival rates and proteinuria up to 48 weeks of age and assessed renal damage and serum anti-double-stranded DNA antibody levels. Additionally, we analyzed B and T cell subsets in lymphoid tissues by flow cytometry and determined the expression of apoptosis-related molecules in lymph nodes. Sh3bp2 gain-of-function mutation alleviated the poor survival rate, proteinuria, and glomerulosclerosis and significantly reduced serum anti-dsDNA antibody levels in Sh3bp2KI/+Faslpr/lpr mice. Additionally, B220+CD4-CD8- T cell population in lymph nodes was decreased in Sh3bp2KI/+Faslpr/lpr mice, which is possibly associated with the observed increase in cleaved caspase-3 and tumor necrosis factor levels. Sh3bp2 gain-of-function mutation ameliorated clinical and immunological phenotypes in lupus-prone mice. Our findings offer better insight into the unique immunopathological roles of SH3BP2 in autoimmune diseases.en-USAttribution-NonCommercial-NoDerivs 3.0 United StatesSH3 domain–binding protein 2Systemic lupus erythematosusMurine lupus modelFaslpr mutationDouble-negative T cellsAnti-dsDNA antibodyTumor necrosis factorMacrophagesDendritic cellsArticle