title: [Enhanced activation of T lymphocytes by urease-deficient recombinant bacillus Calmette-Guérin producing heat shock protein 70-major membrane protein-II fusion protein].
abstract: To activate naïve T cells convincingly using Mycobacterium bovis BCG (BCG), rBCG (BCG-D70M) that was deficient in urease, expressed with gene encoding the fusion of BCG-derived heat shock protein (HSP) 70 and Mycobacterium leprae-derived major membrane protein (MMP)-II, one of the immunodominant Ags of M. leprae, was newly constructed. BCG-D70M was more potent in activation of both CD4+ and CD8+ subsets of naïve T cells than rBCGs including urease-deficient BCG and BCG-70M secreting HSP70-MMP-II fusion protein. BCG-D70M efficiently activated dendritic cells (DC) to induce cytokine production and phenotypic changes, and activated CD4+ T cells even when macrophages were used as APCs. The activation of both subsets of T cells was MHC and CD86 dependent. Pre-treatment of DC with chloroquine inhibited both surface expression of MMP-II on DC and the activation of T cells by BCG-D70M-infected APCs. The naïve CD8+ T cell activation was inhibited by treatment of DC with brefeldin A and lactacystin so that the T cells was activated by TAP- and proteosome-dependent cytosolic cross-priming pathway. From naïve CD8+ T cells, effector T cells producing perforin and memory T cells having migration markers, were produced by BCG-D70M stimulation. BCG-D70M primary infection in C57BL/6 mice produced T cells responsive to in vitro secondary stimulation with MMP-II and HSP70, and more efficiently inhibited the multiplication of subsequently challenged M. leprae than vector control BCG. These results indicate that the triple combination of HSP70, MMP-II and urease depletion may provide useful tool for inducing better activation of naïve T cells.
authors.affiliation: Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases, Tokyo, Japan. mmaki@niid.go.jp
authors.forename: Masahiko
authors.initials: M
authors.lastname: Makino
authors.forename: Tetsu
authors.initials: T
authors.lastname: Mukai
mesh_terms: D000818:Animals; D001500:BCG Vaccine / Q000276:immunology*; D050939:Gene Fusion; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis / Q000276:immunology*; D006801:Humans; D007918:Leprosy / Q000276:immunology* / Q000517:prevention & control; D008213:Lymphocyte Activation / Q000276:immunology*; D008565:Membrane Proteins / Q000096:biosynthesis / Q000276:immunology*; D051379:Mice; D009163:Mycobacterium bovis / Q000378:metabolism*; D011994:Recombinant Proteins / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D001500:BCG Vaccine; D018840:HSP70 Heat-Shock Proteins; D008565:Membrane Proteins; D011994:Recombinant Proteins; C500901:major membrane protein II, Mycobacterium leprae