Syfrig J, Wells C, Daubenberger C, Musoke A J, Naessens J
International Livestock Research Institute, Nairobi, Kenya.
Eur J Cell Biol. 1998 Jun;76(2):125-32. doi: 10.1016/S0171-9335(98)80025-3.
A flow cytometric method using anti-parasite antibodies was developed to measure binding of Theileria parva sporozoites to the target bovine lymphocyte membrane. Parasite-host cell interactions could be inhibited by monoclonal antibodies to bovine MHC class I and partially by one of two antibodies to BoCD45R. Proteolysis of the lymphocyte surface removed CD45R but not MHC class I determinants, and enhanced sporozoite binding. These observations support the hypothesis that CD45R and CD45R antibodies may nonspecifically prevent close approximation between sporozoites and lymphocytes. Interestingly, under normal conditions, sporozoites of T. parva did not attach to lymphocytes from goats, but did so when the cells were treated with the protease, suggesting that receptor(s) for T. parva sporozoites might be present on caprine cells but are not easily accessible. These and other results indicate that proteases may be involved in binding and entry of T. parva sporozoites. Electron microscopy revealed that the process of binding and entry of sporozoites into protease-treated goat lymphocytes was very similar to that of the bovine cells. However, schizonts did not develop and lymphocyte proliferation was not induced, indicating that cell entry by sporozoites and cellular transformation are separate processes.
开发了一种使用抗寄生虫抗体的流式细胞术方法，以测量泰勒虫小泰勒虫裂殖子与靶牛淋巴细胞膜的结合。针对牛MHC I类的单克隆抗体可抑制寄生虫与宿主细胞的相互作用，而针对BoCD45R的两种抗体之一可部分抑制这种相互作用。淋巴细胞表面的蛋白水解作用去除了CD45R，但未去除MHC I类决定簇，并增强了裂殖子的结合。这些观察结果支持以下假设：CD45R和CD45R抗体可能非特异性地阻止裂殖子与淋巴细胞之间的紧密接近。有趣的是，在正常情况下，小泰勒虫裂殖子不会附着在山羊的淋巴细胞上，但在用蛋白酶处理细胞时会附着，这表明小泰勒虫裂殖子的受体可能存在于山羊细胞上，但不易接近。这些结果和其他结果表明，蛋白酶可能参与了小泰勒虫裂殖子的结合和进入。电子显微镜显示，裂殖子与经蛋白酶处理的山羊淋巴细胞的结合和进入过程与牛细胞非常相似。然而，裂殖体没有发育，也没有诱导淋巴细胞增殖，这表明裂殖子进入细胞和细胞转化是两个独立的过程。
