title: Polyclonal activation of naïve T cells by urease deficient-recombinant BCG that produced protein complex composed of heat shock protein 70, CysO and major membrane protein-II.
abstract: BACKGROUND
  Mycobacterium bovis bacillus Calmette-Guérin (BCG) is known to be only partially effective in inhibiting M. tuberculosis (MTB) multiplication in human. A new recombinant (r) urease-deficient BCG (BCG-dHCM) that secretes protein composed of heat shock protein (HSP)70, MTB-derived CysO and major membrane protein (MMP)-II was produced for the efficient production of interferon gamma (IFN-γ) which is an essential element for mycobacteriocidal action and inhibition of neutrophil accumulation in lungs.
  
  
  METHODS
  Human monocyte-derived dendritic cells (DC) and macrophages were differentiated from human monocytes, infected with BCG and autologous T cells-stimulating activity of different constructs of BCG was assessed. C57BL/6 mice were used to test the effectiveness of BCG for the production of T cells responsive to MTB-derived antigens (Ags).
  
  
  RESULTS
  BCG-dHCM intracellularly secreted HSP70-CysO-MMP-II fusion protein, and activated DC by up-regulating Major Histcompatibility Complex (MHC), CD86 and CD83 molecules and enhanced various cytokines production from DC and macrophages. BCG-dHCM activated naïve T cells of both CD4 and CD8 subsets through DC, and memory type CD4+ T cells through macrophages in a manner dependent on MHC and CD86 molecules. These T cell activations were inhibited by the pre-treatment of Ag-presenting cells (APCs) with chloroquine. The single and primary BCG-dHCM-inoculation produced long lasting T cells responsive to in vitro secondarily stimulation with HSP70, CysO, MMP-II and H37Rv-derived cytosolic protein, and partially inhibited the replication of aerosol-challenged MTB.
  
  
  CONCLUSIONS
  The results indicate that introduction of different type of immunogenic molecules into a urease-deficient rBCG is useful for providing polyclonal T cell activating ability to BCG and for production of T cells responsive to secondary stimulation.
authors.affiliation: Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases, 4-2-1 Aobacho, Higashimurayama, Tokyo 189-0002, Japan. ytsuka@nih.go.jp.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Tsukamoto
authors.forename: Yumi
authors.initials: Y
authors.lastname: Maeda
authors.forename: Toshiki
authors.initials: T
authors.lastname: Tamura
authors.forename: Tetsu
authors.initials: T
authors.lastname: Mukai
authors.forename: Masahiko
authors.initials: M
authors.lastname: Makino
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology*; D001500:BCG Vaccine / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology* / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology; D018840:HSP70 Heat-Shock Proteins / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology*; D008264:Macrophages / Q000276:immunology; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009163:Mycobacterium bovis / Q000201:enzymology / Q000276:immunology* / Q000378:metabolism; D009169:Mycobacterium tuberculosis / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology; D014510:Urease / Q000172:deficiency*; D014614:Vaccines, Synthetic / Q000276:immunology
chemical_list: D000942:Antigens, Bacterial; D001500:BCG Vaccine; D001426:Bacterial Proteins; C000598632:CysO protein, Mycobacterium bovis; D016207:Cytokines; D018840:HSP70 Heat-Shock Proteins; D008565:Membrane Proteins; D011994:Recombinant Proteins; D014614:Vaccines, Synthetic; C000598633:major membrane protein-II, Mycobacterium bovis; C072681:Mycobacterium tuberculosis antigens; D007371:Interferon-gamma; D014510:Urease