Expression and purification of recombinant Mycobacterium tuberculosis antigens ESAT-6, CFP-10, and ESAT-6/CFP-10 and their potential use in the and detection of TB

One of the most widely used methods to detect tuberculosis (TB) infection is the tuberculin skin test (TST).full Sequencing of the Mycobacterium tuberculosis (M.tb) genome has led to the identification of several antigens that can be utilized for accurate diagnosis and control of TB. The aim of this study is to produce and purify several specific recombinant M.tb antigens in order to evaluate their potential use in the diagnosis of TB. The recombinant secretory antigens ESAT-6, CFP-10, and ESAT-6/CFP-10 were produced through PCR and cloning methods. To investigate the antigen-specific responses of these recombinant antigens in the detection of TB, ex vivo enzyme-linked immunospot (ELISPOT) tests were performed on samples of 30 clinically diagnosed TB patients. Throughout this study, the selected M.tb antigens were cloned, expressed, and purified in Escherichia coli (BL21). The ELISPOT assays for the detection of TB showed sensitivity values of 93 %, 90 %, and 100 % for recombinant ESAT-6, CFP-10, and ESAT-6/CFP-10 proteins, respectively, which were significantly higher than the values obtained in conventional tuberculin skin test (TST). Our results show that these recombinant antigens can be used as an accurate detecting TB test for Iranian patients.