The Individual Antigenic Specificity of Antibodies to Streptococcal Carbohydrates

Abstract

Although a single electrophoretically uniform antibody component with specificity for the group carbohydrate may comprise the bulk of the γ-globulin in rabbits immunized with streptococcal vaccines, this is not always the case. Not infrequently, electrophoresis may reveal multiple antibody components. Nevertheless, it has been feasible by various preparative procedures to isolate from a single antiserum at least two antibody components with similar reactivity for the carbohydrate both of which are electrophoretically monodisperse. Light chains from such antibodies reveal a restricted pattern when examined by disc electrophoresis. Antibodies to streptococcal carbohydrates have been examined for their individual antigenic specificity. Goats were immunized with isolated Group C and Group A-variant antibodies raised in rabbits. Individual antigenic specificity of these antibodies was brought out by absorption of the goat anti-antiserum with Fr II of pooled normal rabbit sera. Additional absorption of the goat anti-antisera with Fr II diminished but did not eliminate the reactivity for the homologous antibody. Immunoelectrophoretic studies with papain fragments of purified streptococcal antibodies localized the specificity to the Fab fragment. Specificity was not confined to the isolated light chains of the antibody.

The Emergence of Antibodies With Either Identical or Unrelated Individual Antigenic Specificity During Repeated Immunizations With Streptococcal Vaccines

“…The studies reported here extend the earlier observations on the individual antigenic specificity of streptococcal antibodies which were produced after primary immunization (6). Antibodies with identical individual antigenic specificity may occur after both primary and secondary immunization.…”

“…The earlier studies on the uniform properties of streptococcal antibodies have been concerned primarily with antibodies to the carbohydrates of Groups A-variant and C streptococci (1,2,6,12). Similar uniformity is reported here for antibodies to Group A streptococci.…”

“…Immunization Procedures.--The source of rabbits and the immunization schedule for preparing streptococcal group-specific antisera have been previously described (6,17).…”

Quantitative Investigations of Idiotypic Antibodies

“…Anti-antibodies prepared against such populations of molecules generally will not react with antibody of the same specificity from other donors nor with other immunoglobulin molecules of the donor (1, 2, 4), although certain exceptions have been reported (5,6). Kelus and Gell (4) were able to elicit anti-idiotypic antibodies to anti-proteus antibody with nearly all of a large group of donor and recipient rabbits.…”

“…For this purpose 12SI-labeled F(ab~)2 fragments of specifically purified donor antibody were used as the test antigen. (Previous investigations have localized idiotypic determinants to fragment Fab (1,4,6,7)). It was found that in nearly all instances larger amounts of D molecules were precipitable by the indirect method than by direct precipitation.…”