Identification of macrophage and stress-induced proteins of Mycobacterium tuberculosis.

Abstract

Using phosphorimager technology to quantitate differences in protein expression, we have investigated the modulation of protein synthesis by Mycobacterium tuberculosis in response to intracellular residence in human macrophages and, for comparison, in response to various stress conditions during extracellular growth. Proteins of M. tuberculosis growing intracellularly in human THP-1 cells and extracellularly in broth were labeled with [3S]methionine; during intracellular growth, host cell protein synthesis was inhibited with cycloheximide. The metabolically labeled proteins were separated by two-dimensional gel electrophoresis and quantitatively analyzed. Intracellular residence in macrophages induced a profound change in the overall phenotype ofM. tuberculosis. The expression of at least 16 M. tuberculosis proteins was induced (at least a twofold increase compared with growth in broth) and 28 proteins repressed (at least a twofold decrease). Many of the phenotypic changes in protein expression induced during intracellular growth occurred during extracellular growth in response to stress conditions including heat-shock, low pH, and H202. However, the pattern of induced and repressed proteins was unique to each stress condition. Of the 16 macrophage-induced proteins, 6 were absent during extracellular growth under both normal and stress conditions. Such proteins are potential virulence determinants and/or they may be important in the cell-mediated and protective immune response to M. tuberculosis infection. (J. Clin. Invest. 1995. 96:245-249.)

Extraordinarily few organisms of a live recombinant BCG vaccine against tuberculosis induce maximal cell-mediated and protective immunity

“…In contrast, animals immunized with the high dose (1,2,(23)(24)(25)(26). In this regard, the 30 kDa protein is the major protein secreted by M. tuberculosis in broth culture (24) and among the most abundantly expressed proteins of all types produced by M. tuberculosis within human macrophages (27). Second, the 30 kDa protein has a large number of immunodominant T-cell epitopes in both guinea pigs and humans (28,29), allowing it to induce immunoprotection across disparate MHC types in outbred populations.…”

Recombinant BCG expressing Mycobacterium tuberculosis major extracellular proteins

“…The M. tuberculosis 30 kDa protein is not only the major protein secreted into broth culture, but it is also among the major M. tuberculosis proteins of all types expressed in human macrophages infected with M. tuberculosis. [30].…”

Host Responses and Antigens Involved in Protective Immunity to Mycobacterium tuberculosis

“…intracellular growth [180]. Another approach to the investigation of macrophage influence on the mycobacteria has been to study regulatory differences at the genetic level.…”