Characterization of the Secreted MPT53 Antigen of Mycobacterium tuberculosis

Abstract
MPT53 is a secreted protein of Mycobacterium tuberculosis . Southern transfer and hybridization showed mpt53 to be conserved in the M. tuberculosis complex and to have homology with DNA from Mycobacterium avium and other nontuberculous mycobacteria. However, anti-MPT53 polyclonal antibodies detected no antigen in the culture filtrates of M. avium and other nontuberculous mycobacteria. MPT53 of M. tuberculosis induced strong, tuberculosis-specific antibody responses in guinea pigs but induced no delayed-type hypersensitivity. Involvement in immune responses during human tuberculosis was very modest.