A novel monoclonal antibody against A60 antigen of Mycobacterium bovis Bacillus Calmette-Guerin.

Mycobacterium contains several immunologically active substances, which play a principal role in mycobacterial diseases. The majority of the highly antigenic proteins present in mycobacterial homogenates are components of the A60 complex. In this study, A60 antigen was prepared from cytoplasm of Mycobacterium bovis Bacillus Calmette-Guerin (BCG). Cytoplasm was fractionated by passage through the column of sepharose 6B and ConA-sepharose 4B. After purification of spleen cells of the immunized mice, the cells were fused with SP2/0 myeloma cells. Four clone cell lines producing antibody against A60 antigens were established and each clone was tested for immunoreactivity against purified A60 by ELISA and immunoblotting. The clone designated DEB7 reacted strongly with A60. Immunoblotting using MAb DEB7 showed that this MAb binds to a single protein of A60 subunit with a molecular weight of 65 kDa. This subunit of A60 M. bovis recognized by DEB7 MAb could be used to increase the sensitivity and specificity of immunoassay or other potential roles in mycobacterium infection.