Identification of mycobacterial antigens recognized by T lymphocytes

The development of vaccines capable of inducing protective immunity against mycobacterial infection depends in part on the identification of antigenic determinants that activate T cells with antimycobacterial effector function. Various approaches designed to analyze the recognition of mycobacterial antigens by T cells are reviewed. In addition to the established approach of using serologically defined antigens, alternative methods independent of antibody preselection, such as polyacrylamide gel electrophoresis-fractionated immunoblots of mycobacteria, can be used to probe the specificity of the T cell repertoire. Furthermore, the application of recombinant DNA expression combined with that of synthetic peptides whose sequences are predicted to constitute T cell determinants allow the localization of T cell epitopes within a protein. The use of these techniques in defining potentially "pathogenic and protective" T cell epitopes in mycobacteria is discussed.