Improved immunogenicity of mycobacterium tuberculosis Rv0577 by a heterologous prime-boost vaccination strategy in mice

Tuberculosis (TB) remains a major cause of global mortality and morbidity. However, the only available vaccine, Mycobacterium bovis bacillus Calmette-Guerin (BCG), is insufficiently effective against this disease. Therefore, the development of a potent vaccine against TB is urgently needed. Virulence-associated protein Rv0577 from Mycobacterium tuberculosis was demonstrated to induce the maturation of dendritic cells and enhance cellular immunity, and it could be helpful in designing efficacious TB vaccines. In this research, we constructed both protein vaccine and DNA vaccine of Rv0577. We have generated, characterized and studied the immunogenicity induced by different immunization strategies. Antigen-specific antibody and cellular immune responses were evaluated in mice. The best vaccination strategy was achieved with a heterologous DNA prime and protein boost. This strategy proliferated splenocytes, induced high levels of specific antibody responses, a high proportion of CD4+ and CD8+ T cells and Th1 type cytokines. The results in this study showed that the improved immunogenicity can be elicited by Rv0577 with an appropriate vaccination strategy, and it could be considered for developing a novel vaccine against TB.