title: Murine hybridoma-derived antibodies producing circumoval precipitation (COP) reactions with eggs of Schistosoma japonicum.
abstract: Of 7 hybridomas which secrete immunoglobulins binding to crude extracts of Schistosoma japonicum adult worms and/or eggs in solid-phase radioimmunoassays (RIAs), 3 gave positive precipitation reactions in the circumoval precipitin test (COPT). The COPT is a simple and inexpensive immunodiagnostic test for schistosomiasis japonica which involves the incubation of a selected batch of S. japonicum eggs with sera from patients and examination for precipitates one or more days later. Using a competitive RIA with an egg antigen extract and a labelled COPT-positive hybridoma ascites fluid, PwF.41-1-3, the surprising observation was made that only one anti-egg antibody specificity appeared to be represented in the series of 3 antibodies (as ascites fluids). Using sera as inhibitors in the competitive RIA, inhibitory activity (presumably antibodies to the target antigenic determinant of PwF.41-1-3) was readily detected in sera from egg-immunized mice and was of relatively high titre in a strain of mouse (C57BL/6) which can be readily sensitized for large granuloma formation around entrapped eggs in the lungs. Negligible inhibitory activity was found in the sera from S. japonicum-infected patients, even with sera from patients with prominent hepatosplenomegaly. The availability of COPT-positive hybridoma antibodies should facilitate isolation of at least one S. japonicum egg antigen involved in COP reactions and perhaps induction of immunopathological immune responses at least in mice.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D005260:Female; D006801:Humans; D006825:Hybridomas / Q000276:immunology*; D007075:Immunoglobulin M; D051379:Mice; D010063:Ovum / Q000276:immunology*; D011233:Precipitin Tests; D011863:Radioimmunoassay; D012549:Schistosoma japonicum / Q000276:immunology*; D012552:Schistosomiasis / Q000175:diagnosis
chemical_list: D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D007075:Immunoglobulin M