Ub Combination Enhanced Cellular Immune Response Elicited by HSP65 DNA Vaccine against Mycobacterium tuberculosis

This study observed the immune response induced by a HSP65 DNA vaccine fused with UbGR against Mycobacterium tuberculosis. BALB/c mice were inoculated with HSP65 DNA vaccine, UbGR-fused HSP65 DNA vaccine (Ub-GR-HSP65) and blank vector respectively. HSP65 DNA vaccine elicited a Thl-polarized immune response. The Thl-type cytokine (IFN-γ) and proliferative T cell responses from spleen were improved significantly in UbGR-HSP65 group, compared with those in HSP65 DNA vaccine group. Furthermore, this fusion DNA vaccine also led to an increased ratio of IgG2ato IgGl and the cytotoxicity of T cells. IFN-γ intracellular staining of splenocytes indicated that UbGR-HSP65 fusion DNA vaccine could activate CD4+ and CD8+ T cells, with much higher CD8+ T cells. Thus, this study demonstrated that the UbGR fusion could improve HSP65-specific cellular immune responses, which is helpful to protect against TB infection.