T and B cell reactivity to a 42-kDa protein is associated with human resistance to both schistosomiasis mansoni and haematobium.

Egyptian subjects living in areas endemic for Schistosoma mansoni or Schistosoma haematobium were selected on the basis of their apparent extremes of resistance or susceptibility to schistosomiasis and examined for T and B cell responses against the major electrophoretically resolved protein species from soluble adult worm extracts. A 42-kDa band was specifically recognized by a significant majority of subjects resistant to schistosomiasis. The 42-kDa species (p-42) from S. mansoni and S. haematobium were immunologically cross-reactive and induced significant protection in mice and hamsters against infection with cercariae. Amino acid sequence analysis of S. mansoni p-42 showed that it consists predominantly of glyceraldehyde 3-P dehydrogenase (G3PDH), which has been shown to be preferentially recognized by the sera of Brazilian subjects resistant to schistosomiasis mansoni. The present data extend the previous findings and imply that S. mansoni-derived G3PDH represents a target of protective T and B cell-mediated antischistosomiasis immunity in humans.