Construction of a DNA vaccine based on the Mycobacterium tuberculosis Ag85A/MPT64 fusion gene and evaluation of its immunogenicity

The aim of this study was to construct a DNA vaccine based on the Ag85A/MPT64 gene of Mycobacterium tuberculosis (MTB) and analyze its immunogenicity by enzyme-linked immunospot (ELISPOT) assay. The fusion gene encoding Ag85A/MPT64 was amplified by PCR from the genome of the MTB H37Rv strain and cloned into a eukaryotic expression vector followed by confirmation using restriction endonuclease digestion and DNA sequencing. The immunogenicity of the recombinant vector was tested in vivo in BALB/c mice. The serum antibody titers against Ag85A/MPT64 were detected by ELISPOT assay. The number of ELISPOT spots for the mice following immunization with Ag85A/MPT64 was significantly greater than for the negative and blank controls. A DNA vaccine based on the gene encoding the Ag85A/MPT64 fusion protein of MTB was successfully constructed and expressed. Our data may serve as a foundation for further research into the prevention and treatment of tuberculosis and carcinomas.