Anti-poliovirus IgG subclass antibodies in cytomegalovirus infected mice

A considerable strain difference was noted in BALB/c and C57BL/6 mice with regard to the impairment of antibody responses to poliovirus antigens in the course of infection with murine cytomegalovirus (MCMV): a long lasting reduction in antibody formation in BALB/c mice contrasted with an only moderate depression observed in C57BL/6 animals. Analysis of antibody classes and IgG subclasses revealed that anti-poliovirus VP1 antibodies in BALB/c mice were predominantly of the IgG3 subclass, a subclass most drastically affected by MCMV infection, while C57BL/6 mice produced antibodies of the IgM class and of IgG1 and IgG2 subclasses which were reduced to a lesser extent by the infection with MCMV. It is concluded that the strain difference observed may be explained on the basis of differences in the handling of poliovirus antigenic determinants by BALB/c and C57BL/6 mice.