汉族类风湿关节炎患者HLA-DM和-DR基因的表达

Expression of HLA-DM and -DR Gene in Rheumatoid Arthritis Patients in the Han Nationality

目的探讨我国汉族类风湿关节炎（RA]患者的人类白细胞抗原（HLA）-DM（13MA和DMB）基因的表达。方法以33名正常献血者及26例强直性脊柱,3L（AS）患者为对照，应用半定量和竞争性逆转录一多聚酶链式反应（RT—PCR）检测36例RA患者，用抗CD19单克隆抗体包被的磁珠从外周血中分离出B细胞的HLA—DMA、-DMB及-DRB基因转录物的量。并应用Westernblot分析HLA—DM和-DR的蛋白表达量。结果与正常对照组或AS组相比，RA患者的HLA—DMA和-DMB转录物的表达均明显降低（P〈0．01）。而与正常对照组相比，RA患者的DRB转录物的表达差异无显著性（P〉0．05）。RA组的HLA—DM／DR平均比值明显低于正常对照组（P〈001）。从蛋白质水平看，与正常对照组相比，RA患者的DMA／β-actin比值明显降低（P〈0．01），而DKA／β-actin比值在两组间差异无显著性（P〉0．05）。结论RA患者的HLA—DM基因的转录水平和幺白质水平均有明显下降，这在RA的发病过程中可能起了重要作用。

Objective To investigate the expression of HLA-DM （DMA and DMB） gene in patients with rheumatoid arthritis （RA） in the Han nationality. Methods HLA-DMA ,-DMB and -DRB transcripts in purified peripheral blood B cells with anti-CD19mAb-coated magnetic beads from 36 RA patients ,26 ankylosing spondylitis （AS） and 33 matched normal control subjects were analyzed by semiquantitative and competitive RT- PCR. Meanwhile , the expression of HLA-DM and -DR proteins was also quantified by Western blot . Results Compared with normal controls or AS patients , only the transcription of HLA-DMA and DMB from RA patients was significantly decreased （P〈 0.01） ,but no difference in HLA-DRB （P〉 0.05） . An mean DM：DR ratio in RA patients was significantly lower than that in normal controls （P〈 0.01） . The mean ratio of DMA/β-actin in RA patients was dramatically decreased compared with that in normal controls at protein level （P〈 0.01） ,but DRA/β-actin showed no significant difference between the two groups （P〉0.05） . Conclusion This specific HLA-DM down regulation might play an important role in the processes of antigen presentation and autoimmune in RA.