Delineation of human antibody responses to culture filtrate antigens of Mycobacterium tuberculosis.

This study was undertaken to define the antigens in culture filtrates of actively replicating Mycobacterium tuberculosis that are recognized by antibodies from tuberculosis (TB) patients. Two-dimensional Western blots were probed with sera from healthy controls and TB patients that were preabsorbed with Escherichia coli lysates to deplete cross-reactive antibodies. Antibodies from TB patients recognized 26 of the >100 culture filtrate proteins, and the repertoire changed with disease progression. Only 12 of 26 antigens, including 3 proteins implicated in colonization and invasion by mycobacteria (MPT51, MPT32, and 85C), and 9 (as yet undefined proteins) were reactive with sera from TB patients with early noncavitary or cavitary disease. Eight additional antigens, including 4 undefined proteins, were recognized only by sera from a subset of patients with advanced cavitary disease. Studies suggest that 3 of the antigens recognized by sera from patients with early TB (85C, MPT32, and a 88-kDa protein) have strong serodiagnostic potential.