Gliding motility and cytadherence in Mycoplasma penetrans

描述(由申请人提供)：大多数具有极化细胞形态的支原体物种表现出滑动运动，这一过程与与宿主细胞的黏附(细胞黏附)密不可分，但分子机制不确定。此外，不同的支原体系统发育群似乎通过不同的机制黏附和滑动。穿透性支原体是一种主要在艾滋病毒阳性患者中发现的微生物，它似乎通过促进艾滋病毒感染的细胞类型的增殖来促进艾滋病的进展，也表现出极地形态，并已知可钻入宿主上皮细胞。然而，其与宿主细胞相互作用的分子基础是完全未知的，其基因组序列表明缺乏其他生物的细胞黏附蛋白的同源物。初步数据表明，穿透支原体和其他极化支原体一样，在体外表现出滑动运动，其速度与其菌落吸附红细胞(血吸附)的程度有关，表明在该物种中，细胞黏附和滑动也是相关的。我们将通过时间推移显微摄影技术，从速度和最佳滑动条件两个方面表征快速滑动菌株和缓慢滑动菌株的滑动运动性，包括旨在确定穿透支原体滑动能量来源的实验。我们将对已经存在的血吸附(HA)突变体以及我们产生和选择的新的HA突变体的滑动能力进行表征，以进一步研究穿透支原体细胞黏附和滑动运动之间的关系。我们将使用双向聚丙烯酰胺凝胶电泳和质谱仪来鉴定这些突变体中缺失或改变的蛋白质，作为参与细胞黏附和/或滑动运动的候选蛋白质。我们将提高这些蛋白质的抗血清，以开始研究它们在这些过程中如何发挥作用，使用抗体作为功能抑制剂和工具来分析亲本菌株和突变菌株中的亚细胞定位和稳定性。这些实验的结果将揭示一种新的细胞推进的分子机制，最终可能导致合理的治疗设计，并可能对纳米技术机器的开发有用。

DESCRIPTION (provided by applicant): Most mycoplasma species with polarized cell morphologies exhibit gliding motility, a process inextricably intertwined with adherence to host cells (cytadherence) but of uncertain molecular mechanism. Moreover, different phylogenetic groups of mycoplasmas appear to adhere and glide by different mechanisms. Mycoplasma penetrans, an organism found principally in HIV-positive patients in whom it appears to potentiate the progress of AIDS by promoting proliferation of the type of cell that HIV infects, also exhibits polar morphology and is known to burrow into host epithelial cells. However, the molecular basis for its interaction with host cells is entirely unknown, its genome sequence indicating an absence of homologs of cytadherence proteins of other organisms. Preliminary data indicate that M. penetrans, like other polarized mycoplasmas, exhibits gliding motility in vitro, its speed relating to the degree to which its colonies adsorb erythrocytes (hemadsorb), suggesting that in this species, cytadherence and gliding are also related. We will characterize the gliding motility of a fast-gliding strain and a slow-gliding strain by time-lapse microcinematography with respect to speed and optimal gliding conditions, including experiments aimed at identifying the energy source for M. penetrans gliding. We will characterize the gliding ability of both already-existing hemadsorption (HA) mutants as well as new HA mutants that we generate and select in order to further investigate the relationship between cytadherence and gliding motility in M. penetrans. We will use two-dimensional polyacrylamide gel electrophoresis and mass spectrometry to identify proteins that are absent or altered in these mutants as candidates for involvement in cytadherence and/or gliding motility. We will raise antisera against these proteins to begin studies of how they function in these processes, using the antibodies both as inhibitors of function and as tools to analyze subcellular localization and stability in both the parent strain and the mutant strains. The results of these experiments will reveal a novel molecular mechanism for cellular propulsion that might ultimately lead to rational design of therapeutics and might also be useful in the development of nanotechnological machines.