Becker Elisabeth, Hegemann Johannes H
Funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine Universität Düsseldorf, Düsseldorf, Germany.
Microbiologyopen. 2014 Aug;3(4):544-56. doi: 10.1002/mbo3.186. Epub 2014 Jul 1.
The bacterial pathogens Chlamydia trachomatis and C. pneumoniae are obligate intracellular parasites, cause a number of serious diseases, and can infect various cell types in humans. Chlamydial infections are probably initiated by binding of the bacterial outer membrane protein OmcB to host cell glycosaminoglycans (GAGs). Here, we show that all nine members of the polymorphic membrane protein (Pmp) family of C. trachomatis mediate adhesion to human epithelial and endothelial cells. Importantly, exposure of infectious particles to soluble recombinant Pmps blocks subsequent infection, thus implicating an important function of the entire protein family in the infection process. Analogous experiments with pairs of recombinant Pmps or a combination of Pmp and OmcB revealed that all Pmps probably act in an adhesion pathway that is distinct from the OmcB-GAG pathway. Finally, we provide evidence that the Pmps of C. trachomatis and C. pneumoniae exhibit species and tissue specificity. These findings argue for the involvement of C. trachomatis Pmps in the initial phase of infection and suggest that they may interact with a receptor other than the epidermal growth factor receptor recently identified for their counterparts in C. pneumoniae.
细菌病原体沙眼衣原体和肺炎衣原体是专性细胞内寄生虫，可引发多种严重疾病，并能感染人类的多种细胞类型。衣原体感染可能是由细菌外膜蛋白OmcB与宿主细胞糖胺聚糖（GAGs）结合引发的。在此，我们表明沙眼衣原体多形膜蛋白（Pmp）家族的所有九个成员都介导与人类上皮细胞和内皮细胞的黏附。重要的是，将感染性颗粒暴露于可溶性重组Pmps会阻断后续感染，因此表明整个蛋白家族在感染过程中具有重要功能。对重组Pmp对或Pmp与OmcB组合进行的类似实验表明，所有Pmps可能在一条不同于OmcB - GAG途径的黏附途径中发挥作用。最后，我们提供证据表明沙眼衣原体和肺炎衣原体的Pmps具有种属和组织特异性。这些发现表明沙眼衣原体Pmps参与感染的初始阶段，并表明它们可能与一种不同于最近为肺炎衣原体对应蛋白所鉴定的表皮生长因子受体的受体相互作用。
