Production and characterization of monoclonal antibodies to Mycobacterium tuberculosis, M. bovis (BCG) and M. leprae

Abstract

Thirty-two monoclonal antibodies (MoAb) to Mycobacterium tuberculosis H37Rv, M. bovis BCG and M. leprae were produced. The spleen cells of BALB/c mice immunized with sonicated or intact bacilli were fused with Sp2/0-Ag-14 myeloma cells. Many more antibody producing hybridomas were found when M. tuberculosis, rather than M. leprae, was used as the immunogen. The MoAb were characterized by an enzyme immunoassay and immunofluorescence on 16 mycobacterial species. The sodium dodecylsulphate polyacrylamide gel electrophoresis immunoperoxidase assay was used to determine the molecular weight of the antigens detected by the MoAb. Antigens of high, low and intermediate molecular weight were found. Some of the antigens were proteinaceous, others of a glycolipid nature. The immunofluorescence assay proved to be essential for the selection of MoAb since some MoAb reacted only in this assay and not in the enzyme immunoassay. The most specific clones were found in the fusions with spleen cells of mice immunized with intact rather than sonicated bacteria. One MoAb (F29-29) reacted only with M. tuberculosis H37Rv; one (F41-3) only with M. leprae and another (F29-45) reacted with M. tuberculosis and M. gastrii. Several MoAb only reacted with three mycobacterial species: M. tuberculosis, M. kansasii and M. gastrii. Others showed unique patterns of reactivity by enzyme immuno- and immunofluorescence assay. The potential use of the MoAb for the identification of mycobacteria and mycobacterial antigens is discussed.