Identification and characterization of a BCG antigen expressed at the membrane surface of in vitro infected mouse peritoneal macrophages.

A murine monoclonal antibody to Mycobacterium bovis (BCG) (230A4A6) was used to identify an antigenic determinant expressed at the surface of murine peritoneal macrophages infected in vitro. This determinant was shown to be expressed with a delay in infected macrophages following in vitro infection. Isolation of the 230A4A6 reactive antigen showed that it was part of a 12-kD molecule. This protein was shown to be capable of eliciting delayed-type hypersensitivity in infected mice in a standard footpad assay as well as provide stimulus for mitogenesis of BCG-primed spleen cells.