Novel monoclonal antibodies against major antigens of Mycobacterium bovis

MPB70 and MPB83 are among the most characteristically exported proteins def ining a strongly expressed phenotype of Mycobacterium bovis. These proteins are known to be homologous to osteoblast-specific factor 2. By in vitro cu lture of mycobacteria they appear to have a limited species distribution an d to be relatively specific for M. bovis. Virtually identical gents are how ever, present in Mycobacterium tuberculosis. In order to facilitate further research into the immunobiology of these proteins and their potential appl ication for differential diagnosis of tuberculosis as a result of M. bovis, we describe the reactivities of 20 monoclonal antibodies (MoAbs) to these proteins. Immunizing with bovine PPD generated 10 MoAbs. These antibodies r eacted preferentially with the soluble MPB70 antigen using reducing conditi ons in SDS-PAGE with western blotting. Ten MoAbs were generated by immunizi ng mice with fractions derived from a whole cell sonic extract of M. bovis. These antibodies reacted preferentially with the surface exposed MPB83 lip oglycoprotein.