Nonprecipitating and Electrophoretically Restricted Antibodies to Carbohydrate of Group A Streptococcus in the Rat

Hyperimmunization of Sprague-Dawley rats with group A streptococcal vaccine elicited both precipitating and nonprecipitating antibodies to the group-specific carbohydrate of the Streptococcus. The occurrence of nonprecipitating antibodies in the immune response of the rat appeared to be genetically influenced by selec-tive inbreeding that causes a low precipitin response. A number of rats responded to immunization by producing electrophoretically restricted antibody components. This restriction in light-chain heterogeneity confirmed by polyacrylamide gel elec-trophoresis of isolated antibody is apparently genetically influenced and capable of recall after extended periods of nonimmunization. Recently, hyperimmunization of rabbits [1], chickens [2], and rats [3] with streptococcal vac-cines has been shown to stimulate the production of large quantities of precipitating antibody. Not infrequently, however, the response to the vac-cines of a number of rabbits consisted predomi