Zieler H, Garon C F, Fischer E R, Shahabuddin M
Medical Entomology Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-0425, USA.
J Eukaryot Microbiol. 1998 Sep-Oct;45(5):512-20. doi: 10.1111/j.1550-7408.1998.tb05110.x.
Plasmodium gallinaceum ookinetes adhered to Aedes aegypti midgut epithelia when purified ookinetes and isolated midguts were combined in vitro. Ookinetes preferentially bound to the microvillated luminal surface of the midgut, and they seemed to interact with three types of structures on the midgut surface. First, they adhered to and migrated through a network-like matrix, which we have termed microvilli-associated network, that covers the surface of the microvilli. This network forms on the luminal midgut surface in response to blood or protein meals. Second, the ookinetes bound directly to the microvilli on the surface of the midgut and were occasionally found immersed in the thick microvillar layer. Third, the ookinetes associated with accumulations of vesicular structures found interspersed between the microvillated cells of the midgut. The origin of these vesicular structures is unknown, but they correlated with the surface of midgut cells invaded by ookinetes as observed by TEM. After binding to the midgut, ookinetes underwent extensive morphological changes: they frequently developed one or more annular constrictions, and their surface roughened considerably, suggesting that midgut components remain bound to the parasite surface. Our observations suggest that, in a natural infection, the ookinete interacts in a sequential manner with specific components of the midgut surface. Initial binding to the midgut surface may activate the ookinete and cause morphological changes in preparation for invasion of the midgut cells.
当在体外将纯化的鸡疟原虫动合子与分离的中肠相结合时，鸡疟原虫动合子会黏附于埃及伊蚊的中肠上皮细胞。动合子优先结合于中肠微绒毛化的管腔表面，并且它们似乎与中肠表面的三种结构相互作用。首先，它们黏附于并穿过一个我们称为微绒毛相关网络的网络状基质，该基质覆盖微绒毛表面。这个网络在中肠管腔表面因血液或蛋白质餐而形成。其次，动合子直接结合于中肠表面的微绒毛，并且偶尔会发现其沉浸在厚厚的微绒毛层中。第三，动合子与散布于中肠微绒毛化细胞之间的囊泡状结构聚集物相关联。这些囊泡状结构的起源尚不清楚，但通过透射电子显微镜观察发现它们与被动合子侵入的中肠细胞表面相关。动合子与中肠结合后，会发生广泛的形态变化：它们经常形成一个或多个环状缢缩，并且其表面变得相当粗糙，这表明中肠成分仍然结合在寄生虫表面。我们的观察结果表明，在自然感染中，动合子以顺序方式与中肠表面的特定成分相互作用。最初与中肠表面的结合可能会激活动合子，并引起形态变化以准备侵入中肠细胞。
