Heterologous prime-boost BCG with DNA vaccine expressing fusion antigens Rv2299c and Ag85A improves protective efficacy against Mycobacterium tuberculosis in mice

Autor: Juan Wu, Zhidong Hu, Shui-Hua Lu, Xiao-Yong Fan
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Frontiers in Microbiology, Vol 13 (2022)
Druh dokumentu: article
ISSN: 1664-302X
DOI: 10.3389/fmicb.2022.927031
Popis: The development of heterologous prime-boost regimens utilizing Bacille Calmette–Guerin (BCG) as the priming vaccine is a promising approach to improve the efficacy of vaccination against tuberculosis (TB). In this study, we examined the ability of a DNA vaccine that expressed a fusion of antigens Rv2299c and Ag85A to boost BCG immunity and protection against Mycobacterium tuberculosis (Mtb) in Balb/c mice. The fusion DNA vaccine was moderately immunogenic and afforded some protection when used on its own. After a priming BCG vaccination, the DNA boost significantly amplified Th1-type cell-mediated immunity compared to that resulting from either BCG or DNA immunization. In the DNA-boosted mice, Ag-specific CD4+ and CD8+ T cells that were mono-positive for IFN-γ alone were the most prominently expanded in infected lungs. The protective efficacy afforded by BCG against challenge infection was greatly improved by the DNA boost; bacterial loads were significantly reduced in both spleen and lung and histological damage in the lung was less. The use of a DNA vaccine containing the fusion antigens Rv2299c and Ag85A to boost BCG may be a good choice for the rational design of an efficient vaccination strategy against TB.
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