Studies on target molecules for anti-endothelial cells autoantibodies detected in systemic vasculitis.

为了了解系统性血管炎的病理生理学，鉴定和鉴定抗内皮细胞抗体(AECA)的自身抗原(AutoAgs)至关重要，AECA在血管炎中经常被检测到。为此，我们使用了蛋白质组学方法。具体地说，我们分别从人脐静脉内皮细胞(HUVEC)和Hela细胞提取的蛋白质进行双向电泳(2DE)分离。然后，我们通过免疫印迹(WB)检测系统性脉管炎患者血清样本识别的HUVEC特异性蛋白。进一步，我们通过肽质量指纹图谱和MS/MS分析确定了AECA的候选AutoAgs。为鉴定出的AutoAgs制备重组蛋白，并研究其临床意义。结果，我们检测到AECA的50个候选AutoAgs。其中一个已鉴定的自体抗原是过氧化还蛋白II(PRX II)。抗PRX-II自身抗体阳性率为68%，无明显血管炎的胶原病患者为7.3%，正常对照组为4.0%。临床上，抗PRX II的自体抗体的存在与凝血酶-抗凝血酶复合体(TAT)和D-二聚体水平的升高有关。此外，在人脐静脉内皮细胞表面检测到PRX II。此外，抗PRX II的自身抗体经常在大血管炎如大动脉炎综合征中被检测到。综上所述，我们通过蛋白质组学的方法证明了Prx II是AECA的靶标之一。抗PRX II的自身抗体主要存在于血管炎的疾病中，有望成为诊断血管炎的新标记物。

To understand pathophysiology of systemic vasculitis, it would be critical to identify and characterize autoantigens (autoAgs) for the anti-endothelial cell antibody(AECA), which are detected frequently in vasculitis. For this aim, we used proteomics approaches. Specifically, we separated proteins extracted from human umbilical vein endothelial cells(HUVEC) and Hela cells as a reference respectively by 2-dimentional electrophoresis(2DE). We then detected HUVEC-specific proteins which were recognized by serum samples from patients with systemic vasculitis by western blotting(WB). Further, we identified the candidate autoAgs for AECA by peptide mass fingerprinting and the MS/MS analysis. Preparing recombinant proteins for the identified autoAgs, we investigated their clinical significance. As a result, we detected 50 candidate autoAgs for AECA. One of the identified autoAgs was peroxiredoxin II(Prx II). The autoantibodies (autoAbs) to Prx II were detected in 68% of the tested patients with vasculitis, 7.3% in tested patients with collagen diseases but no appearent vasculitis, and 4.0% in healthy controls. Clinically, presence of the autoAbs to Prx II was linked to the elevated levels of the thrombin-antithrombin complex(TAT) and D-dimer. In addition, Prx II was detected on the surface of HUVEC. Further, the autoAbs to Prx II were frequently detected in large-size vasculitis like aortitis syndrome. Taken, together, we demonstrated by the proteomic approach that Prx II is one of the targets of AECA. The autoAb to Prx II, detected predominantly in diseases with vasculitis, would be a new marker for presence of vasculitis.