Characterization of antigens of the nematodeNippostrongylus brasiliensis by monoclonal antibodies

Hybridomas secreting monoclonal antibodies toNippostrongylus brasiliensis antigens were generated by hybridization of IR983F myeloma cells with spleen cells from Lou/M/Wol rats infected with living third-stage larvae. Antibodies specific either for larval or worm antigens were identified by enzyme-linked immunosorbent assays withNippostronylus brasiliensis fragments, homogenates and secretions as antigens. The results demonstrate that all antibodies which recognized larval antigens (38 antibodies) also reacted with worm surfaces. Ten antibodies were specific only for worm antigens. Ten antibodies reacted with worm homogenate, three antibodies recognized components of worm secretion and 17 antibodies combined with acetylcholinesterase. The epitope specificity was investigated by the capacity of various glycosides, aminoacids,N-acetylneuraminic acid and phosphorylcholine to inhibit the binding to worm fragments. The analysis revealed that -methylglucoside, -methylmannoside,N-acetylglucosamine,N-acetylgalactosamine, fucose and the amino acids leucine, phenylalanine, tyrosine, serine, tryptophan did not combine with the antigen-binding sites of the antibodies. Proline, arginine and histidine, however, displayed inhibitory effects. WithN-acetylneuraminic acid as inhibitor three groups of antibodies could be discriminated. At a concentration of 10–20 mM, phosphorylcholine was a potent inhibitor for all antibodies.