Zenian A, Kierszenbaum F
J Parasitol. 1982 Jun;68(3):408-15.
The initial interaction between the surfaces of mouse peritoneal macrophages and Trypanosoma cruzi was examined using bloodstream (trypomastigote) and culture (epimastigote) forms of a predominantly reticulotropic strain of the parasite. Pretreatment with Con A resulted in a marked inhibition of macrophage binding of both forms of the parasite. Con A inhibition of epimastigote binding persisted for at least 4 hr after exposure to Con A whereas the trypomastigote-binding ability of macrophages showed a significant spontaneous recovery (57-79%) after 1 hr whether or not the parasites were present in the cell cultures during that time. Binding of Con A to the macrophage was required for inhibition of parasite attachment since incubation of Con A-treated cells with alpha-methyl mannoside prevented the inhibitory phenomenon when either epimastigotes or trypomastigotes were used. This monosaccharide had an inhibitory effect of its own which was not as marked as that produced by Con A and affected epimastigote but not trypomastigote binding to the phagocytic cells, thus representing an additional difference in the modes of interaction of these forms of the parasite with the macrophage surface. Furthermore, inhibition of either trypomastigote or epimastigote binding to macrophages was not caused by succinyl-Con A (which consists of two monomeric Con A subunits whereas Con A has four) unless the succinyl-Con A-treated macrophages were further incubated with anti-Con A antibodies. This observation suggests the importance of either molecular size or crosslinking of Con A subunits with consequent membrane rearrangement in causing the inhibitory phenomenon. The antibody preparation had no effect on macrophage binding of T. cruzi when tested by itself. These results highlight distinct characteristics of the binding of two forms of T. cruzi differing in their infective capacity to the surface of a host cell.
利用一种主要嗜网状内皮细胞的克氏锥虫株的血流型（锥鞭毛体）和培养型（上鞭毛体），研究了小鼠腹膜巨噬细胞表面与克氏锥虫之间的初始相互作用。用刀豆球蛋白A（Con A）预处理可显著抑制巨噬细胞对两种形式寄生虫的结合。Con A对巨噬细胞结合上鞭毛体的抑制作用在接触Con A后至少持续4小时，而巨噬细胞对锥鞭毛体的结合能力在1小时后显示出显著的自发恢复（57%-79%），无论在此期间细胞培养物中是否存在寄生虫。Con A与巨噬细胞的结合是抑制寄生虫附着所必需的，因为用α-甲基甘露糖苷孵育Con A处理过的细胞可防止抑制现象的发生，无论使用的是上鞭毛体还是锥鞭毛体。这种单糖本身具有抑制作用，但其作用不如Con A显著，且影响上鞭毛体与吞噬细胞的结合，但不影响锥鞭毛体，因此代表了这些形式的寄生虫与巨噬细胞表面相互作用模式的另一个差异。此外，除非用抗Con A抗体进一步孵育琥珀酰-Con A处理过的巨噬细胞，否则琥珀酰-Con A（由两个单体Con A亚基组成，而Con A有四个亚基）不会抑制锥鞭毛体或上鞭毛体与巨噬细胞的结合。这一观察结果表明，Con A亚基的分子大小或交联以及随之而来的膜重排在导致抑制现象中具有重要作用。单独测试时，该抗体制剂对巨噬细胞结合克氏锥虫没有影响。这些结果突出了克氏锥虫两种感染能力不同的形式与宿主细胞表面结合的不同特征。
