Renesto Patricia, Samson Laurent, Ogata Hiroyuki, Azza Saïd, Fourquet Patrick, Gorvel Jean-Pierre, Heinzen Robert A, Raoult Didier
Unité des Rickettsies, CNRS UMR 6020, IFR-48, Faculté de Médecine, 27 Boulevard Jean Moulin, 13385 Marseille, France.
Res Microbiol. 2006 Sep;157(7):605-12. doi: 10.1016/j.resmic.2006.02.002. Epub 2006 Feb 28.
The rickettsial membrane proteins that promote their uptake by eukaryotic host cells are unknown. To identify rickettsial ligand(s) that bind host cell surface proteins, biotinylated epithelial cells were used to probe a nitrocellulose membrane containing rickettsial extracts separated by SDS-PAGE. This overlay assay revealed that two close rickettsial ligands of approximately 32-30 kDa were recognized by host cells. Both proteins were identified using high resolution 2D-PAGE coupled with mass spectrometry analysis. One protein was identified as the C-terminal extremity of rOmpB called the beta-peptide. The second interacting protein was identified as a protein of unknown function encoded by RC1281 and RP828 in Rickettsia conorii and in Rickettsia prowazekii, respectively, that shares strong similarities with other bacterial adhesins. Both proteins are highly conserved within the Rickettsia genus and might play a critical role in their pathogenicity. These data may have important implications for the development of future vaccines against rickettsial infections.
促进立克次氏体被真核宿主细胞摄取的膜蛋白尚不清楚。为了鉴定与宿主细胞表面蛋白结合的立克次氏体配体，使用生物素化的上皮细胞探测含有通过SDS-PAGE分离的立克次氏体提取物的硝酸纤维素膜。这种覆盖分析显示，宿主细胞识别出两种分子量约为32 - 30 kDa的紧密立克次氏体配体。使用高分辨率二维聚丙烯酰胺凝胶电泳结合质谱分析鉴定了这两种蛋白质。一种蛋白质被鉴定为rOmpB的C末端，称为β肽。第二种相互作用蛋白被鉴定为分别由康氏立克次体和普氏立克次体中的RC1281和RP828编码的功能未知的蛋白质，它与其他细菌粘附素具有很强的相似性。这两种蛋白质在立克次氏体属内高度保守，可能在其致病性中起关键作用。这些数据可能对未来抗立克次氏体感染疫苗的开发具有重要意义。
