Production and characterization of a monoclonal antibody (P6) reactive to Mycobacterium tuberculosis

The production and characterization of a murine monoclonal antibody (P6) to Mycobacterium tuberculosis is described. The specificity of the monoclonal antibody, an IgG1/K type, was tested against sonic extracts obtained from 27 mycobacteria and 39 bacteria by an enzyme-linked immunosorbent assay. Apparently it was highly specific for the virulent form of M. tuberculosis (H37Rv) and did not react with avirulent strains of M. tuberculosis (H37Ra) and M. bovis (BCG). It was devoid of reactivity with all other mycobacteria and bacteria except to a reaction of low extent with Nocardia asteroides (11.8%). The antibody recognized intact M. tuberculosis as well as the sonicate. Various pathogenic strains of M. tuberculosis collected from different geographical locations showed a range of reactivity with this monoclonal antibody. The antibody reacted strongly with M. tuberculosis South Indian (79112) and British strain (wild) and to varying extents with other strains of M. tuberculosis tested. In Western immunoblots, it recognized antigens of 45 and 96 KDa of M. tuberculosis (H37Rv).