Studies of mycobacterial antigens, with special reference to Mycobacterium leprae

Abstract

Eight individual antigens were detected in soluble antigen preparations from M. leprae bacilli by using pools of serum samples from lepromatous leprosy patients as antibody reagents in crossed immunoelectrophoresis. Two of these antigens were analyzed further. Antigen 1 gave an elution pattern on Sephadex G-200 corresponding to a MW of 285,000. This antigen was also present in 3 slow-growing and fast-growing mycobacterial species. There was a reaction of complete identity in immunological tests using lepromatous serum pools and with rabbit antisera raised against M. leprae and M. smegmatis. Antigen 21 of M. leprae showed antigenic heterogeneity when compared with other species [this antigen deserves special attention regarding its role in humoral and cellular immunity in leprosy]. Three types of antigenic determinants were detected; 1 (21A) was shared by all mycobacteria, another (21B) was limited to antigen 21 of M. leprae a 3rd (21C) was present in all mycobacteria except the leprosy bacillus. This submolecular heterogeneity may indicate a separate taxonomic position of M. leprae among the mycobacteria.