Miettinen A, Westerlund B, Tarkkanen A M, Törnroth T, Ljungberg P, Renkonen O V, Korhonen T K
Department of Bacteriology and Immunology, University of Helsinki, Finland.
Kidney Int. 1993 Mar;43(3):592-600. doi: 10.1038/ki.1993.87.
Two well characterized bacterial adhesins, the O75X fimbriae of Escherichia coli and the type-3 fimbriae of Klebsiellae, with in vitro affinities to type IV and V collagens, respectively, were used to test whether bacterial components with affinity for glomerular matrix could bind to glomeruli in vivo. The purified fimbrial proteins were injected into rats, and kidney samples were studied by immunofluorescence at two hours to nine months postinjection. The O75X, but not the type-3 fimbriae, formed mesangial deposits that persisted for months. Preincubation of the O75X fimbriae with type IV collagen significantly reduced the glomerular binding. The fimbrial deposits were extracellular, as anti-O75X IgG injected into rats bound to glomeruli. Proteinuria or histological damage could not be detected even after passive or active immunizations of the rats. The results demonstrate that bacterial adhesins may bind in vivo to and persist in glomeruli by their specific affinities. The results also indicate that additional factors provided by the bacteria or the host are needed for glomerular damage to take place.
两种特征明确的细菌黏附素，即大肠杆菌的O75X菌毛和克雷伯菌属的3型菌毛，它们在体外分别对IV型和V型胶原具有亲和力，被用于测试对肾小球基质有亲和力的细菌成分在体内是否能与肾小球结合。将纯化的菌毛蛋白注射到大鼠体内，并在注射后两小时至九个月通过免疫荧光对肾脏样本进行研究。O75X菌毛而非3型菌毛形成了持续数月的系膜沉积物。将O75X菌毛与IV型胶原预孵育可显著降低其与肾小球的结合。菌毛沉积物位于细胞外，因为注射到大鼠体内的抗O75X IgG能与肾小球结合。即使在对大鼠进行被动或主动免疫后，也未检测到蛋白尿或组织学损伤。结果表明，细菌黏附素可能因其特定亲和力在体内与肾小球结合并持续存在。结果还表明，肾小球损伤的发生还需要细菌或宿主提供的其他因素。
