BAFF receptor(B-cell activating factor receptor,BAFF-R), also known astumor necrosis factor receptor superfamily member 13C(TNFRSF13C) andBLyS receptor 3(BR3), is amembrane proteinof theTNF receptorsuperfamily which recognizesBAFF,an essential factor for B cell maturation and survival.[5][6]In humans it is encoded by theTNFRSF13Cgene.[7]
B-cell activating factor(BAFF) enhances B-cell survival in vitro and is a regulator of the peripheralB-cellpopulation. The protein encoded by this gene is a receptor for BAFF and is a type IIItransmembrane proteincontaining a single extracellularphenylalanine-rich domain. It is thought that this receptor is the principal receptor required for BAFF-mediated mature B-cell survival.[7]In B cell maturation, due to regulation by BAFF-R, only a limited amount of B-cell will survive.[8]
Overexpression of BAFF in mice results in mature B-cellhyperplasiaand symptoms ofsystemic lupus erythematosus(SLE). Also, some SLE patients have increased levels of BAFF in serum. Therefore, it has been proposed that abnormally high levels of BAFF may contribute to the pathogenesis of autoimmune diseases by enhancing the survival of autoreactive B cells, which are cells that show immune response to normal body cells.[7]Autoreactive B cells are less sensitive toward BAFF and are usually outcompeted by the normal B cells in the maturation process regulated by low BAFF-R expression. An elevated level of BAFF-R can therefore overcome this decreased response and result in accumulation of autoreactive B cells.[8]
BAFF and BAFF-R pair can also down-regulate the cellapoptosisprocess.[9]
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Kalled SL (October 2006). "Impact of the BAFF/BR3 axis on B cell survival, germinal center maintenance and antibody production".Seminars in Immunology.18(5): 290–6.doi:10.1016/j.smim.2006.06.002.PMID16931038.
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Rolink AG, Melchers F (April 2002). "BAFFled B cells survive and thrive: roles of BAFF in B-cell development".Current Opinion in Immunology.14(2): 266–75.doi:10.1016/S0952-7915(02)00332-1.PMID11869903.
Kim HM, Yu KS, Lee ME, Shin DR, Kim YS, Paik SG, Yoo OJ, Lee H, Lee JO (May 2003). "Crystal structure of the BAFF-BAFF-R complex and its implications for receptor activation".Nature Structural Biology.10(5): 342–8.doi:10.1038/nsb925.hdl:10203/11495.PMID12715002.S2CID11294267.
Gordon NC, Pan B, Hymowitz SG, Yin J, Kelley RF, Cochran AG, Yan M, Dixit VM, Fairbrother WJ, Starovasnik MA (May 2003). "BAFF/BLyS receptor 3 comprises a minimal TNF receptor-like module that encodes a highly focused ligand-binding site".Biochemistry.42(20): 5977–83.doi:10.1021/bi034017g.PMID12755599.
