免疫电镜技术定位SD大鼠肾脏中的Heymann抗原

LOCALIZATION OF HEYMANN ANTIGEN IN THE KIDNEYS OF SPRAGUE-ADWLEY RATS

大鼠用抗致病的小管抗原(Tub-Ag)血清免疫后可产生被动型Heymann肾炎(PHN)。其发病机制属于上皮下IC原位形成。为了进一步对此提供证据,我们应用免疫电镜技术定位了大鼠肾脏中致病的Tub-Ag,实验发现:该抗原多位于肾小球足突基部细胞膜、裂隙孔、近曲小管上皮细胞顶部凹褶及微绒毛基部。提示:肾小球中含有与肾小管刷状缘上Tub-Ag起交叉反应的抗原;PHN的发病机制确为IC原位形成所致。

It has been demonstrated that injection of the antiserum against nephrit-ogenic tubular antigen ( Tub-Ag ) can induce passive Hexraann nephritis ( PHN) in rats and that the pathogenesis of PHN is attributed to the in situ formation of subepithelial immune complex. In order to provide further information about this process we applied immunoelectronmicroscopy to localize the nephr-itogenic Tub-Ag in SD rats. It was found that this antigen was located mainly at the basal portion of the cell mambrane of foot processes and in the filtration slits between pod cytes of the glomeruli, and in the apical invaginati-ons and at the base of microvilli of the proximal tubule epithelial cells. These results suggest glomeruli contain the antigen that cross-reacts with the antibody homologous to the Tub-Ag present in the brush border of tubule epithelium, and confirm the significance of the in situ formation of immune complex in the pathogenesis of PHN.