The human B cell activating factor (BAFF) and APRIL(a proliferation inducing ligand) are both type II molecules belonging to the TNF superfamily. They are expressed by non-B cells, and are down-regulated by mitogenic stimulation.2 BAFF and APRIL bind to at least two receptors: TACI (transmembrane activator and CAML-interactor) and BCMA (B cell maturation antigen), both of which are restricted to B cells.3,4 Ligation of these receptors with recombinant BAFF dramatically increases IgM production by peripheral blood B cells1. Recently a third receptor for BAFF (BAFF-R) was described.5Cell surface BAFF can be cleaved to form a soluble trimeric molecule.2 BCMA-muIg binds to recombinant BAFF-muCD8 and can inhibit binding of this molecule to receptors on Raji cells.
Molecular Structure: A soluble molecule consisting of the murine CD8 alpha signal peptide( 10 amino acids), extracellular (51aa) domain of human BCMA fused to the murine IgG2a Fc (235 aa).
Predicted non glycosylated monomeric weight: 33 kd.
Sequence:
Residual signal peptide and linker amino acids (1) kpqapelrgs(10)
BCMA mature extracellular domain: (11)agqcsqneyfdsllhacipcqlrcssntppltcqrycnasvtnsvkgtnai(61)
linker + Murine IgG2a Fc + Hinge domain:
(62) gteprgptikpcppckcpapnllggpsvfifppkikdvlmislspivtcvvvdvseddpdvqiswfvnnvevhtaqtqthredynstlrvvsalpiqhqdwmsgkefkckvnnkdlpapiertiskpkgsvrapqvyvlpppeeemtkkqvtltcmvtdfmpediyvewtnngktelnykntepvldsdgsyfmysklrvekknwvernsyscsvvheglhnhhttksfsrtpg(296)
Transfectant Cell Line: CHO
Functional Application: BCMA-muIg binds to recombinant BAFF-muCD8 and can inhibit this molecule’s abiltiy to bind to receptors on Raji cells. It has been used in vitro to block binding of recombinant BAFF (6) and function of APRIL (7).
References:
1) Schneider P., J. Tschopp, et al. J. Exp. Med. 1999, 189 (11):1747-1756.
2) Shu, H.B., H. Johnson, W.H. Hui. J Leukoc Biol 1999, 65:680-683.
3) Marsters, S.A., A. Ashkenazi, et al. 2000, Curr Biol 10:785-788.
4) Xia, X., H. Hsu, et al. 2000, J Exp Med , 192(1): 137-143.
5) Thompson J.S., C. Ambrose, et al. Science 2001, 293: 2108-2111.
6) Xu W, A Cerutti, et al. (2007) Nat Immunol 8(3): 294-303. PMID: 17259987.
7) Bing He, Andrea Cerutti, et al. (2007) Immunity 26(6): 812-826.https://doi.org/10.1016/j.immuni.2007.04.014
