Shared epitope for monoclonal IR162 between Anisakis simplex larvae and Clonorchis sinensis and cross-reactivity between antigens

IR162 is a rat monoclonal IgE antibody (mAb). In the investigation of rat I gE production, the antigens recognized by IR162 (IR-Ags) were found to be e xpressed by a variety of helminthic parasites. By western blot analysis, IR 162 detected bands in crude extracts of Anisakis simplex larvae, Clonorchis sinensis, Paragonimus westermani, plerocercoids of Spirometra mansoni, and Toxocara canis. Excretory-secretory material from A. simplex larvae also c ontained a protein recognized by IR162. IR162 mAb obtained from both Serote c and Zymed recognized identical bands of A. simplex larvae. Sandwich enzym e-linked immunosorbent assay analysis indicated that both IR-Ags of A. simp lex larvae (IR-As) and C. sinensis (IR-Cs) were important antigens with res pect, to induction of specific IgG in human infections with these 2 organis ms. Even though minimal cross-reaction between IR-As and IR-Cs was observed using sera from infected individuals, these results indicate that IR-Ags a re found in the parasites examined, that IR-As and IR-Cs are the antigens t hat induce specific antibody in natural infection, and that the epitope tha t binds IR162 is shared by A. simplex larvae and C. sinensis.