[Identification and localization of molecules which intervene in the interaction between Entamoeba histolytica and...

During the initial stages of host-parasite interaction between Entamoeba histolytica and its target cell, superficial molecules of both cells participate. The purpose of this study has been the study of the parasite's proteins which are involved in the process of adhesion, as well as localize the superficial sites of the host which bind with the amebic proteins. Antibodies directed against adhesin 112 kDa, and other amebic adhesins, specifically inhibited the destruction of the monolayers of the MDCK epithelial cell line. Soluble proteins of MDCK cells recognized was separated by electrophoresis and transferred to nitrocellulose paper, the amebic proteins of 112, 90 and 45 to 50 kDa. In a similar fashion, membrane proteins of MDCK cells marked with 125[I] specifically recognized amebic proteins of 112, 90, 45 and 32 kDa, as well as others of higher molecular wight. The localization of the binding sites of the E. histolytica molecules on semi-confluent monolayers of MDCK cells, was brought about by immunofluorescence using antibodies against the parasite's total proteins or against adhesins. For electron microscopy antibodies labelled with peroxidase were used. The amebic proteins were mainly found on the periphery of free cells, land in the intercellular cell junctions of monolayers.