Development of a novel anti ESAT-6 monoclonal antibody for screening of Mycobacterium tuberculosis

Tuberculosis (TB) is a major global public health problem with an estimated one-third of the world's population infected with Mycobacterium tuberculosis, thus necessitating fast and accurate diagnosis of TB. However, the diagnosis of latent infection remains difficult due to the lack of a simple, reliable test for M. tuberculosis infection. The objective of the current study was to generate and characterize a novel monoclonal antibody (mAb) that specifically target the early secretory antigenic target 6 (ESAT-6) protein for tuberculosis (TB) immunological diagnosis. The BALB/c mice were immunized by a peptide with 13 amino acids (amino acid residues 24 to 36) of ESAT-6 protein. Stable hybridomas cell lines were established and mAb was identified by Western Blot, immunoprecipitation (IP) and Enzyme linked immunosorbent assay (ELISA). In addition, this mouse mAb was used to coat plates, and biotin-labelled polyclonal antibodies were used to detect the antigens. Finally, the antibody was verified in 280 patient sputum culture supernatants and pleural effusion aspirates. The positive detection rate of the generated ESAT-6 mAb was 91% in the clinical diagnosis of tuberculosis pleural effusion, and this mAb had a sensitivity of 92.4% and a specificity of 100% in all M. tuberculosis cases. Our data indicated that the mAb generated in this study can potentially serve as a tool in the laboratory diagnosis of TB.