BCR-crosslinking induces a transcription of protein phosphatase component G5PR that is required for mature B-cell survival.
BCR-crosslinking triggers activation-induced cell death (AICD) selectively in the restricted stage of B-cell differentiation. We examined the transcription of a protein phosphatase subunit G5PR in immature and mature B-cells, because absence of this factor augmented cell sensitivity to AICD, associated with increased activation of JNK and Bim. BCR-crosslinking-induced G5pr transcription in AICD-resistant mature splenic IgM(lo)IgD(hi) B-cells but not in AICD susceptible immature IgM(hi)IgD(lo) B-cells. Thus, G5pr induction correlated with the prevention of AICD; High in mature splenic CD23(hi) B-cells but low in immature B-cells of neonatal mice, sub-lethally irradiated mice, or xid mice. Lack of G5pr upregulation was associated with the prolonged activation of JNK. The G5pr cDNA transfection protected an immature B-cell line WEHI-231 from BCR-mediated AICD. The differential expression of G5PR might be responsible for the antigen-dependent selection of B-cells.
Huq Ronny
Faisal Mahmudul
FM
Department of Immunology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto 860-8556, Japan.
Igarashi
Hideya
H
Sakaguchi
Nobuo
N
D000818:Animals; D000944:Antigens, Differentiation, B-Lymphocyte / Q000378:metabolism*; D001402:B-Lymphocytes / Q000166:cytology* / Q000378:metabolism*; D002454:Cell Differentiation; D002460:Cell Line; D049109:Cell Proliferation; D002470:Cell Survival / Q000502:physiology*; D003432:Cross-Linking Reagents; D051379:Mice; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism*; D015533:Transcriptional Activation / Q000502:physiology
D000944:Antigens, Differentiation, B-Lymphocyte; D003432:Cross-Linking Reagents; D011947:Receptors, Antigen, B-Cell; D010749:Phosphoprotein Phosphatases