Induction of a specific strong polyantigenic cellular immune response after short-term chemotherapy controls bacillary reactivation in murine and guinea pig experimental models of tuberculosis.
RUTI is a therapeutic vaccine that is generated from detoxified and liposomed Mycobacterium tuberculosis cell fragments that has demonstrated its efficacy in the control of bacillus reactivation after short-term chemotherapy. The aim of this study was to characterize the cellular immune response generated after the therapeutic administration of RUTI and to corroborate the lack of toxicity of the vaccine. Mouse and guinea pig experimental models were infected with a low-dose M. tuberculosis aerosol. RUTI-treated animals showed the lowest bacillary load in both experimental models. RUTI also decreased the percentage of pulmonary granulomatous infiltration in the mouse and guinea pig models. This was not the case after Mycobacterium bovis BCG treatment. Cellular immunity was studied through the characterization of the intracellular gamma interferon (IFN-gamma)-producing cells after the splenocytes' stimulation with M. tuberculosis-specific structural and growth-related antigens. Our data show that the difference between the therapeutic administration of BCG and RUTI resides mainly in the stronger activation of IFN-gamma(+) CD4(+) cells and CD8(+) cells against tuberculin purified protein derivative, ESAT-6, and Ag85B that RUTI generates. Both vaccines also triggered a specific immune response against the M. tuberculosis structural antigens Ag16kDa and Ag38kDa and a marked mRNA expression of IFN-gamma, tumor necrosis factor, interleukin-12, inducible nitric oxide synthase, and RANTES in the lung. The results show that RUTI's therapeutic effect is linked not only to the induction of a Th1 response but also to the stimulation of a quicker and stronger specific immunity against structural and growth-related antigens that reduces both the bacillary load and the pulmonary pathology.
Unitat de Tuberculosi Experimental, Department of Microbiology, Fundació Institut per a la Investigació en Ciències de la Salut Germans Trias i Pujol, Universitat Autònoma de Barcelona, Badalona, Catalonia, Spain.
Evelyn
E
Guirado
Olga
O
Gil
Neus
N
Cáceres
Mahavir
M
Singh
Cristina
C
Vilaplana
Pere-Joan
PJ
Cardona
D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology*; D000995:Antitubercular Agents / Q000008:administration & dosage / Q000627:therapeutic use; D001500:BCG Vaccine / Q000008:administration & dosage / Q000276:immunology; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D007538:Isoniazid / Q000008:administration & dosage / Q000627:therapeutic use; D008081:Liposomes / Q000008:administration & dosage / Q000627:therapeutic use; D051379:Mice; D008810:Mice, Inbred C57BL; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D012293:Rifampin / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000627:therapeutic use; D013047:Specific Pathogen-Free Organisms; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors; D016896:Treatment Outcome; D032581:Tuberculosis Vaccines / Q000008:administration & dosage / Q000627:therapeutic use; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy / Q000276:immunology / Q000628:therapy
D000942:Antigens, Bacterial; D000995:Antitubercular Agents; D001500:BCG Vaccine; D008081:Liposomes; D032581:Tuberculosis Vaccines; D007371:Interferon-gamma; D007538:Isoniazid; D012293:Rifampin; C018421:rifapentine