A major immunogen in Schistosoma mansoni infections is homologous to the heat-shock protein Hsp70.

A 70,000 mol wt protein of Schistosoma mansoni was shown to be a major immunogen that invariably elicited an antibody response in infected humans. The universality of the response to this abundant antigen was confirmed in experimental animals and included the antibody response associated with the protective irradiated cercarial vaccine. We identified the 70,000 mol wt antigen as an S. mansoni homologue of the major eukaryotic heat-shock protein hsp70 by DNA sequence analysis of a cDNA insert from a lambda gt11 clone expressing the antigen and located the immunodominant epitope near the COOH-terminus of the molecule. The antigenic relationship of hsp70 to schistosome infections suggested an important role for this protein in parasite development and pathogenesis.