寻常型天疱疮抗原细胞外区3-4表位的致病性研究

The study on the pathogenicity of the extracellular domain of pemphigus vulgaris antigen

目的研究寻常型天疱疮抗原(pemphigusvulgarisantigenPVA)细胞外区3-4(extracellulardomainEC3-4)表位的致病性并与EC1-2进行比较。方法:通过寻常型天疱疮新生鼠模型,构建含有PVAEC3-4片段的重组质粒,进行融合蛋白的表达和纯化。通过免疫家兔获得特异性抗血清,皮下注射至BALB/c新生鼠,从临床、组织病理、电镜和免疫荧光等方面进行评价。结果:实验组小鼠经皮下注射特异性兔抗EC3-4抗体后均未出现红斑、水疱等临床表现;组织病理亦未见表皮内水疱形成,可见棘层松解现象。电镜显示棘层细胞排列松散,细胞间距增宽,部分桥粒分离、溶解、消失。免疫荧光以正常小鼠皮肤为底物,显示IgG荧光沉积。结论:PVAEC3-4表位亦为PVA的致病性表位。

Objective: To establish a PV neonatal mouse model and study the pathogenesis of the extracellular domain 3-4 (EC3-4) of pemphigus vulgaris antigen (PVA) by comparing to EC1-2 epitope. Methods: The vector containing PVA EC3-4 gene was constructed. Then EC3-4 epitope fusion protein (FP) was expressed and purified. The specific antibody produced by immunizing the rabbits with EC3-4 FP was injected to BALB/c neonatal mice. The injected mice were investigated by morphology, histopathology, electronic microscopy and immunofluorescence. Results: No morphologic changes, such as visible erythema or blisters, were detected. Acantholysis was identified by histopathology, but no intraepithelial vesicle was observed. Electronic microscopy showed an enlarged intracellular space and dissolved desmosomes between keratinocytes of the stratum spinosum. Using normal mouse skin cryosection as substrate, immunofluorescent staining showed the IgG deposition among the keratinocytes. Conclusion: PVA EC3-4 epitope is also the pathogenic one in PVA.