title: Characterization of the memory/activated T cells that mediate the long-lived host response against tuberculosis after bacillus Calmette-Guérin or DNA vaccination.
abstract: The memory/activated T cells, which mediate the long-lived host response against tuberculosis, in mice immunized with either bacillus Calmette-Guérin (BCG) or mycobacterium heat-shock protein 65 (hsp 65) antigen expressed from plasmid DNA (DNA-hsp 65), were characterized. Protection against Mycobacterium tuberculosis challenge by DNA-hsp 65 vaccination was associated with the presence of lymph node T-cell populations in which CD8+/CD44hi interferon-gamma (IFN-gamma)-producing/cytotoxic cells were prominent even after 8 or 15 months of plasmid DNA-mediated immunizations, whereas after BCG vaccination the majority were CD4+/CD44lo IFN-gamma-producing T cells. When the cells were separated into CD4+CD8- and CD8+CD4- and then into CD44hi and CD44lo types, CD44lo cells were essentially unable to transfer protection in adoptive transfer experiments, the most protective CD44hi cells were CD8+CD4- and those from DNA-vaccinated mice were much more protective than those from BCG-immunized mice. The frequency of protective T cells and the level of protection were increased up to 8 months and decreased after 15 months following DNA or BCG immunizations.
authors.affiliation: Department of Parasitology, Microbiology and Immunology, School of Medicine of Ribeirão Preto, University of São Paulo.
authors.forename: C L
authors.initials: CL
authors.lastname: Silva
authors.forename: V L
authors.initials: VL
authors.lastname: Bonato
authors.forename: V M
authors.initials: VM
authors.lastname: Lima
authors.forename: L H
authors.initials: LH
authors.lastname: Faccioli
authors.forename: S C
authors.initials: SC
authors.lastname: Leão
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D001500:BCG Vaccine / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D018834:Chaperonin 60; D018833:Chaperonins / Q000276:immunology; D018960:Hyaluronan Receptors / Q000032:analysis; D007156:Immunologic Memory; D007371:Interferon-gamma / Q000096:biosynthesis; D008198:Lymph Nodes / Q000276:immunology; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D014376:Tuberculosis / Q000276:immunology*; D019444:Vaccines, DNA / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D001500:BCG Vaccine; D001426:Bacterial Proteins; D018834:Chaperonin 60; D018960:Hyaluronan Receptors; D019444:Vaccines, DNA; C074119:heat-shock protein 65, Mycobacterium; D007371:Interferon-gamma; D018833:Chaperonins