title: Killed but metabolically active Mycobacterium bovis bacillus Calmette-Guérin retains the antitumor ability of live bacillus Calmette-Guérin.
abstract: OBJECTIVE
  Mycobacterium bovis bacillus Calmette-Guérin is the most effective treatment for high risk noninvasive bladder cancer. Although bacillus Calmette-Guérin immunotherapy clearly decreases recurrence and progression rates, side effects are common and infection with the bacillus has been described. For these reasons it is necessary to find safer alternatives to the live bacillus. We explored the possibility of using killed but metabolically active bacillus Calmette-Guérin.
  
  
  METHODS
  T24, J82 and RT4 bladder tumor cell lines were cultured with live and irradiation or heat treated bacillus Calmette-Guérin Connaught. We measured the inhibition of cell proliferation and the production of cytokines in cell culture supernatants. Peripheral mononuclear blood cells were also infected and the production of different cytokines in cell culture supernatants was analyzed. Peripheral blood mononuclear cell and cell culture supernatants activated by mycobacteria were then cultured with T24 cells to analyze whether they showed cytotoxic activity.
  
  
  RESULTS
  Compared to the other bacillus Calmette-Guérin treatments, γ irradiated bacillus Calmette-Guérin showed activity similar to that of the live bacillus for inhibiting tumor growth and inducing cytokine production. Irradiated bacillus Calmette-Guérin showed metabolic activity and, thus, was considered killed but metabolically active. This is the treatment that most accurately preserved the mycobacterial structure. Killed but metabolically active bacillus Calmette-Guérin induced cytokine production by infected peripheral mononuclear blood cells. Mycobacteria activated peripheral blood mononuclear cell and cell supernatants showed cytotoxic activity against tumor cells, retaining the antitumor capacity of the live bacillus.
  
  
  CONCLUSIONS
  Our results suggest that killed but metabolically active bacillus Calmette-Guérin could be considered a safer immunotherapy alternative to treatment with the live bacillus.
authors: Universitat Autònoma de Barcelona, Barcelona, Spain.
authors: Silvia
authors: S
authors: Secanella-Fandos
authors: Universitat Autònoma de Barcelona, Barcelona, Spain.
authors: Estela
authors: E
authors: Noguera-Ortega
authors: Universitat Autònoma de Barcelona, Barcelona, Spain.
authors: Francesc
authors: F
authors: Olivares
authors: Universitat Autònoma de Barcelona, Barcelona, Spain.
authors: Marina
authors: M
authors: Luquin
authors: Universitat Autònoma de Barcelona, Barcelona, Spain. Electronic address: esther.julian@uab.cat.
authors: Esther
authors: E
authors: Julián
mesh_terms: D000276:Adjuvants, Immunologic / Q000627:therapeutic use*; D001500:BCG Vaccine / Q000627:therapeutic use*; D006801:Humans; D009163:Mycobacterium bovis / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy*; D015164:Vaccines, Inactivated / Q000627:therapeutic use
chemical_list: D000276:Adjuvants, Immunologic; D001500:BCG Vaccine; D015164:Vaccines, Inactivated
keywords: BCG vaccine; immunotherapy; inactivated; metabolic phenomena; urinary bladder neoplasms; vaccines