Expression, characterization and therapeutic efficacy of chimeric Fab of anti-idiotypic antibody NP30 against Schistosoma japonicum

► A human-mouse chimeric Fab of monoclonal anti-idiotypic antibody NP30 (chFab-NP30) against Schistosoma japonicum was constructed and expressed in E. coli. ► The purified chFab-NP30 inhibited the binding of parent NP30 to sera from schistosomiasis patients in a dose-dependent manner. ► Administration of the chimeric Fab in vivo increased the survival rate, reduced egg burdens and ameliorated organ pathology of mice with acute schistosomiasis. ► chFab-NP30 is a promising candidate to be used as a specific and efficient recombinant antibody against acute schistosomiasis japonica.