Biochemical and functional analysis of extracellular stress proteins of Mesocestoides corti.

Previous studies of the serum antibody response in mice to Mesocestoides corti infection indicated that molecules released by the parasite influenced the production of IgM and IgG1 to the exclusion of other isotypes. Two proteins isolated from M. corti culture supernatants were found to be homologous to the 70-kDa heat shock proteins (hsp70) and Escherichia coli GroEL families of stress proteins. The proliferative responses of splenic lymphocytes from infected mice were assessed to unfractionated M. corti supernatants as well as the 70- and 60-kDa stress protein homologs isolated from supernatants. Lymphocytes from infected mice respond to complete supernatant and both of the isolated p70 and p60 stress protein homologs. In addition, supernatant from M. corti cultures stimulates an in vitro antibody response restricted to IgM and IgG1; the same isotypes induced during infection. These results suggest that stress proteins play an integral part in the immune response to M. corti and the associated isotype restriction.