Nakajima K, Itoh K, Nagatani K, Okawa-Takatsuji M, Fujii T, Kuroki H, Katsuragawa Y, Aotsuka S, Mimori A
Division of Rheumatic Diseases, International Medical Centre of Japan, Tokyo.
Scand J Rheumatol. 2007 Sep-Oct;36(5):365-72. doi: 10.1080/03009740701286615.
The elevated expression of B-cell-activating factor belonging to the TNF family (BAFF) is associated with systemic autoimmune disease, including rheumatoid arthritis (RA). The present study was undertaken to determine the distribution of BAFF and its receptor BAFF-R in the cells residing in the rheumatoid synovium.
The expression of BAFF and BAFF-R in synovial tissues obtained from 12 RA patients was examined by immunohistochemistry and flow cytometry. The mRNA expression of these molecules was determined by reverse transcriptase polymerase chain reaction (RT-PCR). Soluble BAFF levels were measured with an enzyme-linked immunosorbent assay (ELISA). Fibroblast-like synoviocytes (FLS) purified from the RA (RA-FLS) were co-cultured with peripheral B cells. The degree of apoptosis in the B cells was measured to assess the effects on the viability of the B cells.
The RA synovium showed focal or diffuse infiltration of mononuclear cells (MNCs), and one specimen showed germinal centre (GC)-like structures. Synovial sublining cells, but not lining cells, expressed BAFF. These sublining cells were negative for BAFF-R. BAFF and BAFF-R were expressed in B and T cells extracted from the RA synovium. Notably, RA-FLS spontaneously expressed cytoplasmic BAFF after 4-6 passages; however, they did not express BAFF or BAFF-R on their cell surface. RA-FLS could support the survival of B cells by preventing their apoptosis, but its effect on B cells might not be BAFF dependent.
BAFF and BAFF-R are widely expressed in the RA synovium. The cells residing in the RA synovium might affect each other through BAFF.
肿瘤坏死因子家族成员B细胞激活因子（BAFF）表达升高与包括类风湿关节炎（RA）在内的系统性自身免疫病相关。本研究旨在确定BAFF及其受体BAFF-R在类风湿滑膜组织细胞中的分布。
采用免疫组织化学和流式细胞术检测12例RA患者滑膜组织中BAFF和BAFF-R的表达。通过逆转录聚合酶链反应（RT-PCR）测定这些分子的mRNA表达。采用酶联免疫吸附测定（ELISA）检测可溶性BAFF水平。将从RA患者中纯化的成纤维样滑膜细胞（FLS）（RA-FLS）与外周血B细胞共培养。检测B细胞凋亡程度以评估对B细胞活力的影响。
RA滑膜显示单核细胞（MNCs）局灶性或弥漫性浸润，1例标本显示生发中心（GC）样结构。滑膜衬里下层细胞而非衬里细胞表达BAFF。这些衬里下层细胞BAFF-R呈阴性。BAFF和BAFF-R在从RA滑膜中提取的B细胞和T细胞中表达。值得注意的是，RA-FLS传代4-6次后自发表达细胞质BAFF；然而，它们在细胞表面不表达BAFF或BAFF-R。RA-FLS可通过防止B细胞凋亡来支持其存活，但其对B细胞的作用可能不依赖BAFF。
BAFF和BAFF-R在RA滑膜中广泛表达。RA滑膜中的细胞可能通过BAFF相互影响。
