Contribution of BCAP to maintenance of mature B cells through c-Rel.
Mice deficient in the B cell adaptor for phosphoinositide 3-kinase (BCAP) have reduced numbers of mature B lymphocytes, which show defects in cell survival and proliferation. We found here that the NF-kappa B (Rel) pathway was impaired in BCAP-deficient mature B cells and that NF-kappa B target genes, indispensable for cell survival and division, were not induced in response to B cell receptor (BCR) stimulation. Among the NF-kappa B (Rel) family, expression of c-Rel was specifically reduced in BCAP-deficient B cells. Retrovirus-mediated reintroduction of c-Rel restored the pool size of immunoglobulin (Ig)M(lo)IgD(hi) mature B cells in the spleen as well as proliferative responses to BCR stimulation. These results indicate BCAP is essential in the maintenance of mature B cells through functional coupling with c-Rel.
Yamazaki
Tetsuo
T
Department of Molecular Genetics, Institute for Liver Research, Kansai Medical University, Moriguchi 570-8506, Japan.
Kurosaki
Tomohiro
T
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism*; D020569:Proto-Oncogene Proteins c-rel / Q000378:metabolism*
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D016328:NF-kappa B; C487978:Pik3ap1 protein, mouse; D020569:Proto-Oncogene Proteins c-rel