The killing effect of subclasses of mouse IgG antibodies on schistosomula of Schistosoma japonicum.

ABSTRACT

The killing effect of IgG antibodies in sera from S. japonicum infected mice on schistosomula of S. japonicum was studied in vitro in the presence of complement. Immune mouse sera were fractionated over Protein A-Sepharose and IgG1, IgG2a, IgG2b and IgG3 were purified by affinity chromatography. The killing activity of each subclass of IgG antibodies against schistosomula was observed only in the presence of complement. The activity of IgG1 was higher than that of the other subclasses of IgG. In combination of the two or three subclasses of IgG, the additive mortality rate was given in all combinations of each subclass of IgG. These results support the view that the combination of various subclasses of IgG antibodies potentiates the resultant lethal effect on schistosomula.