Schenkman S, Diaz C, Nussenzweig V
Department of Pathology, New York University Medical Center, New York 10016.
Exp Parasitol. 1991 Jan;72(1):76-86. doi: 10.1016/0014-4894(91)90123-e.
We have used glutaraldehyde-fixed target cells to study the attachment phase of cell invasion by live trypomastigotes of Trypanosoma cruzi, and determined that attachment is polarized and receptor-mediated. T. cruzi trypomastigotes bind much less efficiently to confluent epithelial cells, which are polarized, than to sparse epithelial cells. When the tight junctions of confluent epithelial cells are disrupted by removing Ca2+ from the incubation medium before glutaraldehyde fixation, binding of T. cruzi increases. T. cruzi also shows preference for attachment underneath cells or to the edges of cells. The binding occurs within a few minutes, is saturable, and is influenced by the parasite developmental stage. Fab fragment derived from monoclonal antibodies that immunoprecipitate a 160-kDa molecule present only on the surface of trypomastigotes inhibit adhesion to fixed and live cells. Future characterization of the target cell receptors for this molecule and the use of fixed target cells should facilitate studies of the mechanisms involved in the initial interaction of T. cruzi with its host cells.
我们使用戊二醛固定的靶细胞来研究克氏锥虫活锥鞭毛体入侵细胞的附着阶段，并确定附着是极化的且由受体介导。克氏锥虫锥鞭毛体与极化的汇合上皮细胞结合的效率远低于与稀疏上皮细胞的结合效率。当在戊二醛固定前通过从孵育培养基中去除Ca2+破坏汇合上皮细胞的紧密连接时，克氏锥虫的结合增加。克氏锥虫还表现出偏好附着在细胞下方或细胞边缘。这种结合在几分钟内发生，具有饱和性，并受寄生虫发育阶段的影响。源自单克隆抗体的Fab片段可免疫沉淀仅存在于锥鞭毛体表面的160 kDa分子，该片段可抑制对固定细胞和活细胞的粘附。对该分子的靶细胞受体的进一步表征以及固定靶细胞的使用应有助于研究克氏锥虫与其宿主细胞初始相互作用的机制。
