Construction of the eukaryotic expression plasmids of Mycobacterium tuberculosis ESAT-6 antigen and its immunogenicity / 中华传染病杂志

ABSTRACT

Objective To construct the eukaryotic expression plasmids of Mycobacterium tuberculosis ESAT-6 antigen and to investigate its immunogenicity in mice. Methods The sequence encoding ESAT-6 was amplified by PCR from Mycobacterium tuberculosis H37Rv genomic DNA. Then, the amplified fragment was sub-cloned into pVAC expression vector. The eukaryotic expression plasmid pVAC-ESAT-6 was transfected into Vero E6 cells with liposome. The mRNA expression of pVAC-esat-6 in Vero E6 cells was detected by RT-PCR and its expression product was analyzed by Western-blot. The plasmid pVAC-esat-6 was introduced into the mice by gene gun injection. The specific antibody to ESAT-6 and the level of IFN-? in supernatant of spleno-lymphocyte cultures were detected by ELISA methods. Results The recombinant plasmid pVAC-esat-6 was successfully constructed, and the expression of ESAT-6 was also detected in vitro. After vaccinated three times, the mice produced specific antibody and the level of IFN-? in supernatant of spleno-lymphocyte cultures in group of pVAC-esat-6 was significantly higher than group of vector alone (P