The occurrence of homogeneous antibodies and antigenic selection of kappa light chains to streptococcal carbohydrates in Monash rabbits.

Abstract

SummaryA mixed breed of rabbits bred at Monash University has been shown to produce electrophoretically monodisperse (homogeneous) antibodies to the group specific carbohydrates of streptococci. All rabbits given primary immunization with Group B or Group C streptococcal vaccines showed more than one homogeneous immunoglobulin when sera were examined by cellulose acetate electrophoresis. These homogeneous components were shown to be antibodies to the group specific carbohydrate. Antibody levels to the carbohydrate varied from 1 to 10 mg/ml antiserum. Fractionation of anti‐Group B serum by anion exchange chromatography showed that heterogeneous anti‐streptococcal antibody was also present, but was specific for cellular constituents other than the group carbohydrate. Monash rabbits immunized with non‐streptococcal antigens have shown a normal heterogeneous antibody response.A goat antiserum to rabbit Fab fragments was shown to distinguish between rabbit κ and λ chains in gel diffusion reactions. Antibodies to the group carbohydrates were purified and tested for their immunoglobulin class and light chain type using the anti‐Fab serum and specific anti‐immunoglobulin sera. In each case the antibody consisted of both IgM and IgG molecules, but contained only κ light chains.