Two unlinked genetic loci interact to control the human immune response to type III group B streptococcal antigen

Serum samples were collected from 30 healthy adult Caucasian volunteers before and after immunization with native type III polysaccharide of group B streptococcus. Serum antibody to this polysaccharide was measured and sera were typed for several Gm and Km(1) allotypes. A significant interactive effect of Gm(23) and Km(1) was found on immune responsiveness to native type III group B streptococcus polysaccharide antigen.