CHARACTERIZATION OF MOUSE MONOCLONAL-ANTIBODIES AGAINST COMMON AND REPEATED EPITOPES OF DIFFERENT DEVELOPMENTAL STAGES OF SCHISTOSOMA-MANSONI

Eight IgM monoclonal antibodies (mAbs) obtained from a Schistosoma man soni chronically infected mouse immunized twice with adult worms butan olic extract (BE) and soluble egg antigen (SEA) were characterized by immunochemical methods. An intense cross-reactivity between different developmental stages was observed by indirect immunofluorescence assay (IIFA) with five anti-SEA mAbs. These mAbs appeared to recognize glyc osidic residues, as suggested by 1) the inhibition of their reactivity by periodate oxidation of SEA, 2) the multiple polypeptide recognitio n in radioimmunoprecipitation and immunoblot assays and 3) reactivity with KLH. Anti-SEA mAbs were able to mediate in vitro killing of schis tosomula but they were not consistently able to mediate passive transf er immunity in vivo. Three of anti-SEA mAbs were suitable for the perf ormance of a sandwich ELISA for antibody detection in S. mansoni infec ted patients, allowing an increase in the signal to noise ratio as com pared to the direct ELISA SEA method. Three anti-BE mAbs showed a more stage restricted pattern of antigen recognition by IIFA. Only one out of three seemed to be directed against glycan residues, but the other mAbs showed a plural pattern of polypeptide recognition on BE immunob lot, suggesting that repeated epitopic motifs are also present in diff erent proteins within the same parasite developmental stage.