Cross-reactive immune responses to Mycobacterium vaccae, Mycobacterium tuberculosis and Bacillus Calmette-Guerin / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the cross-reactive immune responses to Mycobacterium vac-cae (M. vaccae), Mycobacterium tuberculosis (M. tuberculosis, H37Rv) and Mycobacterium bovis Bacillus Calmette-Guerin ( BCG) for providing reference for the development of new vaccines with M. vaccae. Meth-ods M. vaccae (ATCC95051), M. tuberculosis (H37Rv) and BCG (China strain) were cultured on L-J solid media and harvested. Total bacterial protein antigens prepared by ultrasonic disruption were used to im-munize BALB/c mice. IgG antibodies in serum samples were detected with enzyme-linked immunosorbent assay ( ELISA) to evaluate humoral immune responses. Cellular immunity was assessed by detecting various cytokines with cytokine release assay ( CRA) . Results The mice that were respectively immunized with the three mycobacterial antigens could produce high titers of antibodies ( IgG) and high levels of IFN-γand IL-2, but low levels of IL-4 and IL-10. Results of the cross reactivity tests showed that ATCC95051, H37Rv and BCG were able to cross-react with the immunized mice, and all of them induced high levels of IFN-γ, IL-2 and IgG antibodies. Conclusions The three Mycobacteria mainly elicited Th1 immune responses. There were cross-reactive immune responses to M. vaccae, M. tuberculosis and BCG, which might provide ref-erence for using M. vaccae in the development of new anti-tuberculous vaccines.