background and objectives: esat-6 (6-kdaearly secretory antigenic target) and cfp-10 (10-kda culture filtrate protein) have been described as dominant antigens recognized by t-cells and considered as virulence factors in mycobacterium tuberculosis . the aim of this study was to clone, express and purify recombinant esat-6 andcfp-10 proteins of m. tuberculosis in soluble form. materials and meth...

BACKGROUND To evaluate interleukin (IL)-2 and interferon (IFN)-γ secreting T-cells in parallel for the differentiation of latent infection with Mycobacterium tuberculosis infection (LTBI) from active tuberculosis. METHODS Following ex-vivo stimulation of peripheral blood mononuclear cells (PBMC) with M. tuberculosis-specific antigens early secretory antigenic target (ESAT)-6 and culture filtr...

In this issue of the Journal of Bacteriology, Chen and colleagues (1) report a novel observation regarding the mycobacterial ESX-1 (ESAT-6 system-1/type VII) protein secretion system. Although the mechanisms underlying their observations are not yet understood, their exciting results unlink the in vitro secretion of the two major ESX-1 substrates, ESAT-6 (EsxA) and CFP-10 (EsxB), from M. tuberc...

In this issue of the Journal of Bacteriology, Chen and colleagues (1) report a novel observation regarding the mycobacterial ESX-1 (ESAT-6 system-1/type VII) protein secretion system. Although the mechanisms underlying their observations are not yet understood, their exciting results unlink the in vitro secretion of the two major ESX-1 substrates, ESAT-6 (EsxA) and CFP-10 (EsxB), from M. tuberc...

FRET is a light microscopy method for detecting protein-protein interactions within intact cells. The FRET protocol presented here is for CFP- and YFP-tagged proteins examined with an argon laser on a scanning confocal microscope. FRET is assayed by one of the most straightforward approaches available, namely, acceptor photobleaching. In this procedure, the YFP-tagged protein (the FRET "accepto...

A major goal for in vivo biology is to develop models which can express multiple colors of fluorescent proteins in order to image many processes simultaneously in real time. Towards this goal, the cyan fluorescent protein (CFP) nude mouse was developed by crossing non-transgenic nude mice with the transgenic CK/ECFP mouse in which the beta-actin promoter drives expression of CFP in almost all t...

Differential delayed-type hypersensitivity skin testing with tuberculin purified protein derivatives from Mycobacterium bovis and M. avium is the standard for diagnosing bovine tuberculosis. However, improved tests based on defined, specific antigens are urgently needed. In the present study, a combination of bioinformatics, molecular biology, and bovine models of infection were used to screen ...

BACKGROUND HIV-associated immune defects inhibit tuberculosis (TB) diagnosis, promote development of extrapulmonary TB and paucibacillary pulmonary TB cases with atypical radiographic features, and increase TB relapse rates. We therefore assessed the diagnostic performance of a novel assay that directly quantitates serum levels of the Mycobacterium tuberculosis (Mtb) virulence factor 10-kDa cul...

Specialized secretion systems of pathogenic bacteria commonly transport multiple effectors that act in concert to control and exploit the host cell as a replication-permissive niche. Both the Mycobacterium marinum and the Mycobacterium tuberculosis genomes contain an extended region of difference 1 (extRD1) locus that encodes one such pathway, the early secretory antigenic target 6 (ESAT-6) sys...