CD1-restricted presentation of lipid or glycolipid antigens derived from Mycobacterium tuberculosis has been demonstrated by in vitro experiments using cultured T-cell lines. In the present work, the frequency of T-cell responses to natural mycobacterial lipids was analyzed in ex vivo studies of peripheral blood lymphocytes from human patients with pulmonary tuberculosis, from asymptomatic indi...

CD8(+) T cells are thought to play an important role in protective immunity to tuberculosis. Although several nonprotein ligands have been identified for CD1-restricted CD8(+) CTLs, epitopes for classical MHC class I-restricted CD8(+) T cells, which most likely represent a majority among CD8(+) T cells, have remained ill defined. HLA-A*0201 is one of the most prevalent class I alleles, with a f...

tuberculosis is a chronic mycobacterial infection. the main effector cells against mycobacterium tuberculosis are cd4+ t lymphocytes. our objective in this research was to evaluate the quantity of t lymphocytes and their subpopulations before and after treatments with combination of 4 drugs (rifampcin, isoniaside, pyrasinamide, ethambutal) for 2 months directly in sputum-positive tuberculosis p...

Protective immunity to Mycobacterium tuberculosis is poorly understood, but mounting evidence, at least in animal models, implicates major histocompatibility complex class I-restricted CD8+ T cells as an essential component. By using a highly sensitive assay for single cell interferon gamma release, we screened an array of M. tuberculosis antigen-derived peptides congruent with HLA class I alle...

IFN-γ is crucial for protection against Mycobacterium tuberculosis. miR-29 was recently shown to non-redundantly inhibit IFN-γ. Here, we investigated IFN-γ and miR-29a expression dynamics of CD4(+) T cells from patients during active tuberculosis (TB) (n = 32) and in household contacts who were latently M. tuberculosis infected (n = 19) from Ghana. Whereas M. tuberculosis-specific IFN-γ express...

Most vaccines and basic studies of T cell epitopes in Mycobacterium tuberculosis emphasize water-soluble proteins that are secreted into the extracellular space and presented in the context of MHC class II. Much less is known about the role of Ags retained within the cell wall. We used polyclonal T cells from infected humans to probe for responses to immunodominant Ags in the M. tuberculosis ce...

Mounting evidence points to CD8+ T cells playing an important role in protective immunity against Mycobacterium tuberculosis. The only available vaccine against tuberculosis, bacillus Calmette Guérin (BCG), has traditionally been viewed not to induce these cells optimally. In this study, we show that vaccination of human newborns with BCG does indeed induce a specific CD8+ T cell response. Thes...

Although IFN-gamma is necessary for survival of Mycobacterium tuberculosis infection in people and animal models, it may not be sufficient to clear the infection, and IFN-gamma is not a reliable correlate of protection. To determine whether IFN-gamma-independent mechanisms of immunity exist, we developed a murine ex vivo culture system that directly evaluates the ability of splenic or lung lymp...

BACKGROUND Although it has been recognized that Mycobacterium tuberculosis contains large amounts of Toll-like receptor 2 (TLR2) ligands, their direct effects on CD4(+) T cells and the clinical implications have not been determined. METHODS With the recent finding that activated CD4(+) T cells express TLR2 as a costimulatory receptor, we hypothesized that M. tuberculosis and its components ma...