title: Specificity of T cells in human resistance to Mycobacterium tuberculosis infection.
abstract: Secreted proteins are considered to have an important role in inducing resistance to Mycobacterium tuberculosis infection. We analyzed the proliferation of PBMC from five healthy tuberculin-positive individuals, four tuberculosis patients, and six tuberculin-negative healthy controls to the whole bacilli, the 38- and 10-kDa-secreted antigens, and the 65- and 71-kDa hsp. Comparing the proliferative responses between the two mycobacterial-secreted proteins, we have found that both the 38- and the 10-kDa antigens were recognized by PBMC from healthy tuberculin-positive individuals. However, the magnitude of the proliferation caused by the 10-kDa antigen was significantly higher (P < 0.005) than that with the 38-kDa protein. It was a finding of importance that proliferation to the 10-kDa antigen was comparable to that elicited by the whole bacilli. Characterization of proliferative responses toward the 10-kDa antigen demonstrates that human cells process the 10-kDa antigen prior to its recognition by T cells, and that this process might be through lysosomal pathways. These data confirm the strong T cell response against the M. tuberculosis 10-kDa antigen and demonstrate, for the first time, characterization of cellular activation toward this antigen. The magnitude of the proliferative responses to the 65-kDa hsp in the healthy tuberculin-positive subjects compared with tuberculosis patients was not significantly different (P > 0.01). Finally, PBMC from the healthy tuberculin-positive individuals did not recognize the M. tuberculosis 71-kDa hsp. In summary, human resistant cells to tuberculosis respond to different classes of antigens, including constitutive cell wall proteins, secreted antigens, and hsp.
authors.affiliation: Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Mexico, D.F.
authors.forename: P
authors.initials: P
authors.lastname: Mendez-Samperio
authors.forename: L
authors.initials: L
authors.lastname: Gonzalez-Garcia
authors.forename: P R
authors.initials: PR
authors.lastname: Pineda-Fragoso
authors.forename: E
authors.initials: E
authors.lastname: Ramos-Sanchez
mesh_terms: D000942:Antigens, Bacterial / Q000276:immunology*; D005260:Female; D006360:Heat-Shock Proteins / Q000276:immunology; D006801:Humans; D008213:Lymphocyte Activation; D008297:Male; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D011994:Recombinant Proteins; D013601:T-Lymphocytes / Q000276:immunology*; D014376:Tuberculosis / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D006360:Heat-Shock Proteins; D011994:Recombinant Proteins