Immunogenicity of Type-specific C-mycoside Glycopeptidolipids of Mycobacteria

Specific rabbit antibodies were obtained from the inoculation of a complex composed of methylated bovine serum albumin and the superficial type-specific C-mycoside glycopeptidolipid (GPL) antigens from serovar 20 of the Mycobacterium avium-M. intracellulare-M. scrofulaceum complex. Although the GPLs on their own are serologically active, they require the protein carrier for immunogenicity. Antibodies to the complex were detected by seroagglutination, gel diffusion, and indirect immunofluorescence. Cross-reaction was observed in the case of just one of 16 M. avium-M. intracellulare-M. scrofulaceum complex serovars tested (serovar 41). Double gel diffusion and immunoelectrophoresis showed two major antigen-antibody complexes in the reaction between anti-GPL-methylated bovine serum albumin and the GPL antigens. The studies of migration pattern and absorption indicated that immunoglobulin M was responsible for one of these complexes, whereas the antibody responsible for the second complex was unidentified. The specific anti-GPL serum is a useful tool for the identification and classification of atypical mycobacteria and for the study of the fate of the organisms and their superficies during phagocytosis.