Autoantibody-producing RP105(-) B cells, from patients with systemic lupus erythematosus, showed more preferential expression of BCMA compared with BAFF-R than normal subjects

作者：Koarada Syuichi^*; Tada Yoshifumi; Sohma Yoshiaki; Haruta Yoshio; Suematsu Rie; Mitamura Mio; Inoue Hisako; Ehara Hiromi; Tokoro Yusuke; Ohta Akihide; Nagasawa Kohei

来源：Rheumatology, 2010, 49(4): 662-670.

DOI：10.1093/rheumatology/kep437

• SLE
• B cells
• Autoantibody
• B-cell maturation antigen
• B-cell activating factor
• B-cell activating factor receptor
• Transmembrane activator and cyclophilin ligand interactor
• A proliferation-inducing ligand
• RP105 (CD180)
• CD40L

Objective. B cells lacking RP105 produce autoantibodies in patients with SLE. Expression of B-cell activating factor (BAFF) binding receptors (BBRs) and survival of RP105(-) B cells from SLE patients were examined.
Methods. Detection of difference of gene expression between RP105(-) and RP105(+) B cells was done by DNA microarrays. Surface expression was confirmed by flow cytometry. The contribution of BAFF, a proliferation-inducing ligand (APRIL) and monomers/trimers of sCD40L to survival of RP105(-) and RP105(+) B cells was examined.
Results. Gene expression of B-cell maturation antigen (BCMA) was different among BBRs in RP105(-) and RP105(+) B cells in SLE. Preferential expression of BCMA on RP105(-) B cells was confirmed compared with RP105(+) B cells by flow cytometry, although BAFF receptor (BAFF-R) expression on RP105(-) B cells was significantly lower. Additionally, relative ratios of BCMA/BAFF-R expression on RP105(-) B cells were increased significantly in SLE patients compared with normal subjects. Stimulation by sCD40L decreased the number of surviving RP105(-) and RP105(+) B cells in vitro. RP105(+) B cells were not rescued from sCD40L-induced cell death by BAFF and/or APRIL. In contrast, either BAFF or APRIL maintained the survival of RP105(-) B cells due to avoidance of cell death. Activated RP105(-) B cells reduced BAFF-R and increased BCMA levels.
Conclusions. RP105(-) B cells from SLE patients showed more preferential expression of BCMA compared with BAFF-R than normal subjects, and were possibly regulated by BAFF/APRIL. Our results provide a new insight of BCMA and their ligands in B cells from SLE patients.

• 出版日期2010-4