Proteins released from Mycobacterium tuberculosis during growth

Abstract

Proteins secreted from Mycobacterium tuberculosis during growth are believed to be important for protective immunity against tuberculosis. We have investigated the growth of M. tuberculosis in an enriched liquid medium. The release of isocitrate dehydrogenase from the bacilli served as a marker of autolysis and was observed during the late logarithmic growth phase. The release of proteins during the culture period was investigated by enzyme-linked immunosorbent assay and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Three major groups of proteins, which differed markedly with respect to profile of release and location in intact bacilli, were defined. A short-term filtrate devoid of autolytic products was defined and found to be composed of 33 major components. Five proteins were identified by monoclonal antibodies. Pronounced superoxide dismutase activity was detected in the filtrate. The enzyme was purified and identified as a dominating component of short-term filtrate.

Increased levels of interferon‐γ primed by culture filtrate proteins antigen and CpG‐ODN immunization do not confer significant protection against Mycobacterium tuberculosis infection

“…[8][9][10][11] Among the different candidates for a protein to use in devising a subunit vaccine against TB, antigens actively secreted in M. tuberculosis cultures have generated particular interest. 12,13 Culture filtrate proteins (CFPs) are the principal targets of the T-cell response in mice, both at the height of infection 14 and in a state of memory Denise Morais da Fonseca, 1 Célio Lopes Silva, 1 Marina Oliveira e Paula, 1 Edson Garcia Soares, 2 Gilles Marchal, 3 Cynthia Horn, 4 and Vânia Luiza Deperon Bonato 1…”

Antigenicity of Mycobacterium paratuberculosis superoxide dismutase in mice

“…Superoxide dismutase (SOD) is found within the bacteria but extracellular SOD has been also observed in Mycobacterium tuberculosis (MTB) [8]. Indeed, Andersen et al [9] found the SOD to be among the three main secreted protein of MTB. Like the MTB SOD, the SOD of Mycobacterium avium was shown to be secreted without a peptide leader [10,11].…”

Expression of Mycobacterium tuberculosis MPT64 in recombinant Myco. smegmatis: purification, immunogenicity and application to skin tests for tuberculosis

“…These secreted proteins accumulate early in the culture media during active replication of Myco. tuberculosis [2], and have been identified on the surface of mycobacteria [3]. Secreted proteins are recognized early in the course of experimental tuberculosis infection [1] and stimulate T cell proliferation and interferon-gamma (IFN-) release from peripheral blood mononuclear cells (PBMC) of TB patients [4].…”

“…Early culture filtrates of Myco. tuberculosis contain a complex mixture of secreted proteins [2]. Some, such as the three closely related 30-32-kD proteins of the antigen 85 family, are widely shared by all mycobacterial species studied.…”