Potential cross‐reactivity of monoclonal antibodies against clinically relevant mycobacteria

Summary Tuberculosis is a disease caused by the M ycobacterium tuberculosis complex ( MTb ). In 2011, global mortality due to tuberculosis was 1·4 million individuals. The only available vaccine is the attenuated M . bovis [bacillus Calmette–Guérin ( BCG )] strain, which confers variable protection against pulmonary tuberculosis. Some widely distributed non‐tuberculous mycobacteria ( NTM ), such as M . avium and M . arupense , are also potential pathogens for humans. This work aimed to produce and characterize monoclonal antibodies against the M . bovis   BCG M exico strain of the MTb , M . avium subs. hominissuis and the M . arupense strain from NTM . Hybridomas were produced from splenocytes of BALB /c female mice immunized with radiation‐inactivated mycobacteria, and the immunoglobulin ( Ig)G2a antibody‐producing clones with the highest antigenic recognition were selected. The selected clones, Mbv 2 A 10 for M . bovis   BCG M exico, Mav 3H1 for M . avium and M ar 2 D 10 for M . arupense , were used in further studies. Enzyme‐linked immunosorbent assay ( ELISA ) and immune proteomics analyses characterized the clones as having the highest cross‐reactivity with mycobacteria. Using mass spectrometry, a number of proteins recognized by the monoclonal antibody ( mAb ) clones were identified. These proteins had roles in metabolic processes, hypoxia, cell cycle and dormancy. In addition, a Clustal W and Immune Epitope Database ( IEDB ) in‐silico analysis was performed in protein sequences that result in the conserved regions within probability epitopes that could be recognized for Mbv2A10 and Mav3H1 clones.