Molecular identity of a major antigen ofSchistosoma mansoniwhich cross-reacts withTrichinella spiralisandFasciola hepatica

Abstract

SUMMARYA glycoprotein cross-reactive amongSchistosoma mansoni, Trichinella spiralisandFasciola hepaticawas identified and characterized by use of monoclonal antibodies prepared againstS. mansoniglycoproteins. Four monoclonal antibodies recognized the same antigen which was one of the majorS. mansoniglycoproteins precipitated by sera of hosts infected with eitherS. mansoniorT. spiralis. This antigen was expressed inS. mansonicercariae, adult male and female worms, and eggs, and inS. haematobiumbut not inS. japonicum. Radio-immunoprecipitation and partial proteolytic digest mapping showed that the monoclonal antibodies each recognized a unique epitope. These epitopes were heat labile, sensitive to chaotropic agents, but resistant to reduction and alkylation or digestion with glycosidases, indicating that the recognition sites were amino acids and not carbohydrates. Epitopes recognized by the four monoclonal antibodies were expressed inF. hepatica, whereas only two were expressed inT. spiralis. Analysis by immunofluorescence microscopy showed that the antigen was expressed inS. mansoniin the parenchymal tissue and on the surface of the dorsal tubercles; in matureF. hepaticain the parenchymal tissue, vitelline glands and eggs; in immatureF. hepaticaonly in the parenchymal tissue and in larvalT. spiralisin the hypodermis.