Arroyo R, González-Robles A, Martínez-Palomo A, Alderete J F
Department of Microbiology, University of Texas Health Science Center, San Antonio 78284-7758.
Mol Microbiol. 1993 Jan;7(2):299-309. doi: 10.1111/j.1365-2958.1993.tb01121.x.
The cytoadherence of Trichomonas vaginalis, the sexually transmitted flagellated protozoan, to vaginal epithelial cells (VECs) is the key to infection. Electron microscopy revealed that in vitro-grown parasites having typical globular shape transformed rapidly after contact with VECs into thin, flat, amoeboid cells, maximizing the area of adhesion to the surface of VECs. Amoebic trichomonads formed filopodia and pseudopodia, which interdigitated at distinct sites on the plasma membrane of target cells. In contrast, the amoeboid transformation did not occur for T. vaginalis interacting with HeLa cells, the previously used in vitro host model cell. Initial parasitism of VECs by a single organism was followed by establishment of a monolayer of trichomonads on the host cell. Finally, parasites adhering to either VECs or HeLa cells were induced to synthesize greater amounts of the four previously described adhesins. Therefore, distinct signals after contact with either epithelial cell type leads to the morphological transformation and/or induction of adhesion synthesis by T. vaginalis.
性传播的鞭毛虫原生动物阴道毛滴虫对阴道上皮细胞（VECs）的细胞粘附是感染的关键。电子显微镜显示，体外培养的具有典型球形的寄生虫在与VECs接触后迅速转变为薄的、扁平的、变形虫样细胞，从而使与VECs表面的粘附面积最大化。变形虫样毛滴虫形成丝状伪足和伪足，它们在靶细胞质膜的不同部位相互交错。相比之下，与之前使用的体外宿主模型细胞HeLa细胞相互作用的阴道毛滴虫并未发生变形虫样转变。单个生物体对VECs的初始寄生之后是在宿主细胞上建立一层毛滴虫。最后，诱导粘附于VECs或HeLa细胞的寄生虫合成更多量的四种先前描述的粘附素。因此，与任何一种上皮细胞类型接触后的不同信号会导致阴道毛滴虫的形态转变和/或粘附合成的诱导。
