Buc-Caron M H, Condamine H, Kerjaschki D
Service de Génétique cellulaire du Collège de France et de l'Institut Pasteur, Unité Associée CNRS 1148, Paris.
Ann Inst Pasteur Immunol. 1987 Sep-Oct;138(5):707-22. doi: 10.1016/s0769-2625(87)80026-0.
Heymann nephritis is a glomerulonephritis induced in rat by injecting kidney extracts. The responsible antigen is known to consist of two high molecular weight glycoproteins, gp330 and gp300, located in renal tubular brush border cells. We show that rabbit antibodies made against purified rat gp330 react in immunofluorescence tests with several polarized epithelia present in pre- and post-implantation mouse embryos, as well as with murine trophoblastoma cells. Immunoprecipitation experiments demonstrate that anti-gp330 antibodies also recognize two components with relative molecular weights of 330 and 300 Kd in mouse embryonic cells. Furthermore, sequential immunoprecipitation experiments and limited proteolysis tests suggest that these two components are identical with brushin, a glycoprotein set known to be present in a mouse early embryonic epithelium and in adult kidney cells. Finally, ultrastructural studies demonstrate that anti-gp330 antibodies react with molecules preferentially located in coated pits of murine early epithelial cells. These results show that Heymann nephritis antigen has an embryonic counterpart closely related to, if not identical with, previously identified brushin glycoproteins. These molecules could be a receptor to an unknown ligand or a structural component of coated pit membrane.
海曼肾炎是通过注射肾脏提取物在大鼠中诱发的一种肾小球肾炎。已知其致病抗原由位于肾小管刷状缘细胞中的两种高分子量糖蛋白gp330和gp300组成。我们发现，针对纯化的大鼠gp330制备的兔抗体在免疫荧光试验中与植入前和植入后小鼠胚胎中存在的几种极化上皮细胞以及小鼠滋养层细胞瘤细胞发生反应。免疫沉淀实验表明，抗gp330抗体在小鼠胚胎细胞中也能识别相对分子质量为330和300kd的两种成分。此外，连续免疫沉淀实验和有限蛋白酶解试验表明，这两种成分与已知存在于小鼠早期胚胎上皮和成年肾细胞中的一种糖蛋白——刷蛋白相同。最后，超微结构研究表明，抗gp330抗体与优先位于小鼠早期上皮细胞被膜小窝中的分子发生反应。这些结果表明，海曼肾炎抗原具有一种胚胎对应物，它与先前鉴定的刷蛋白糖蛋白密切相关，甚至可能相同。这些分子可能是一种未知配体的受体，或者是被膜小窝膜的结构成分。
