T-cell clones were established from Mycobacterium tuberculosis-immunized mice. These clones had the phenotype Thy-1+ L3T4+ Lyt-2- and were restricted by the H-2I-A locus. After antigen stimulation, the T-cell clones secreted interleukin-2 and gamma interferon. Factors produced by these T-cell clones activated normal bone marrow macrophages for antimycobacterial activity in vitro. Furthermore, t...

Several lines of evidence suggest that CD8 T cells are important in protection against tuberculosis. To understand the function of this cell population in the immune response against Mycobacterium tuberculosis, T cells from lungs of M. tuberculosis-infected mice were examined by flow cytometry. The kinetics of the appearance of CD8 T cells in lungs of infected mice closely paralleled that of CD...

One-third of the world’s population is estimated to be infected with Mycobacterium tuberculosis (M. tuberculosis) and remains asymptomatic. Of these, only 5-10% of the individuals are known to develop active tuberculosis in their lifetime. Host T cell mediated adaptive immune responses are of critical importance against M. tuberculosis infection. However the immune mechanisms that determine why...

We conducted a long-term follow-up study in patients with rheumatic diseases who were candidates for biologics treatment to evaluate the effects of biologic agents on the risk of tuberculosis infection and the effect of prophylactic treatment on tuberculosis activation. One hundred one patients with rheumatic diseases who were candidates for biologics treatment were recruited, and 57 healthy su...

BACKGROUND Type 2 diabetes mellitus (DM) is a major risk factor for the development of active pulmonary tuberculosis, although the immunological mechanisms underlying this interaction remain unexplored. The influence of poorly controlled diabetes on pathogen-specific T-helper 1 (Th1) and T-helper 17 (Th17) responses have not been examined. METHODS To identify the role of Th1 and Th17 cells in...

Protective immunity against Mycobacterium tuberculosis requires the generation of cell-mediated immunity. We investigated the expression and role of programmed death 1 (PD-1) and its ligands, molecules known to modulate T cell activation, in the regulation of IFN-gamma production and lytic degranulation during human tuberculosis. We demonstrated that specific Ag-stimulation increased CD3+PD-1+ ...

We previously found that human NK cells lyse Mycobacterium tuberculosis-infected monocytes and alveolar macrophages and upregulate CD8(+) T cell responses. We also found that human NK cells produce IL-22, which inhibits intracellular growth of M. tuberculosis, and that NK cells lyse M. tuberculosis-expanded CD4(+)CD25(+)FOXP3(+) T regulatory cells (Tregs). To determine the role of NK cells duri...

Vaccination of mice with plasmid DNA carrying the gene for the major secreted mycobacterial antigen 85A (Ag85A) from Mycobacterium tuberculosis is a powerful technique for generating robust specific Thl helper T-cell responses, CD8+-mediated cytotoxicity, and protection against M. tuberculosis challenge (K. Huygen et al., Nat. Med. 2:893-898, 1996). We have now analyzed in more detail the antig...

In order to identify T cell epitopes within the Mycobacterium leprae 45-kD serine-rich antigen, we analysed responses to overlapping 17-mer peptides encompassing the whole antigen in non-exposed UK controls, Pakistani leprosy patients and tuberculosis patients in both the United Kingdom and Pakistan. This antigen has been described as M. leprae-specific, although it has a hypothetical homologue...