title: Serobiological differentiation between antischistosomal (Schistosoma mansoni) antisera.
abstract: Sera from chronically infected mice and from mice immunized with a soluble worm extract were both cytotoxic in vitro to schistosomula and exhibited similar antibody titers when tested by the indirect fluorescent antibody (IFA) technique with unmodified schistosomula. However, only the former type of antiserum was passively protective and highly reactive by IFA technique with schistosomula modified by heat or by successive heat and pronase treatments. These results indicate that in vitro cytotoxic antibody activity and passive protectivity are unrelated antischistosomal activities and suggest therefore that quantitatively or qualitatively different antibodies may be involved in their execution. It is yet unclear whether antibodies to the "treatment resistant" determinants are involved in protection, although they reach maximal expression between 10 and 16 weeks after infection, at which time protective immunity was demonstrable. The treated schistosomula are capable of inducing antibodies in mice and the antisera raised against them exhibited different patterns of activity when cross-tested by the IFA technique with untreated and treated schistosomula. The antigenic hierarchy of the "treatment resistant" determinants is discussed in view of the various serological findings.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D003602:Cytotoxicity, Immunologic; D005260:Female; D005455:Fluorescent Antibody Technique; D006358:Hot Temperature; D007106:Immune Sera / Q000008:administration & dosage / Q000276:immunology*; D007112:Immunity, Maternally-Acquired; D051379:Mice; D011402:Pronase / Q000494:pharmacology; D012550:Schistosoma mansoni / Q000276:immunology*; D012552:Schistosomiasis / Q000276:immunology*
chemical_list: D007106:Immune Sera; D011402:Pronase