Prokaryotic expression and immunogenicity analysis of latent infection antigen Rv2628c-Rv1737c fusion protein of Mycobacterium tuberculosis / 中国人兽共患病学报

ABSTRACT

According to the codon characteristics of the prokaryotic system,we synthesized the optimized Rv2628c-Rv1737c nucleic acid sequence and constructed the expression plasmid pET24a-Rv2628c-Rv1737c.After sequencing,expression in E.coli was induced.The fusion protein was found in inclusion bodies.After renaturation and affinity chromatography purifi-cation,the Rv2628c-Rv1737c recombinant protein,with a molecular weight of 57 kDa and a purity exceeding 90％,was ob-tained.The recombinant protein was used to stimulate PBMC cells from different patients,and the differences in IFN-γ mRNA expression were analyzed with q-PCR.The Rv2628c-Rv1737c fusion protein stimulated patients with TB,particularly latent TB infection(LTBI).The level of IFN-γ mRNA in PBMC cells was higher than that in healthy controls(P＜0.05).Mice immu-nized with BCG+Rv2628c-Rv1737c/DMT showed significant induction of high levels of IgG antibodies.Rv2628c-Rv1737c re-combinant protein,as a latent infection antigen,is recognized by PBMCs cells infected with TB,with strong immunogenicity,and thus may serve as a potential TB subunit vaccine target antigen.This protein may be used to prevent TB infection,particu-larly latent infection,and to perform laboratory diagnosis.