The role of Vdelta2+T-cells in patients with active Mycobacterium tuberculosis infection and tuberculin anergy.
METHODS
Tuberculosis (TB) is one of the most common major infectious diseases. In humans, acquired protective immunity to Mycobacterium tuberculosis depends on T-cells and involves multiple T-cell subsets; however, the pathways used by T-cells to restrict the growth of M. tuberculosis are poorly understood.


OBJECTIVE
To investigate the possible role of Vdelta2+T-cells and regulatory T-cells in the immune response to M. tuberculosis. As Vdelta2+T-cell function has been shown to be impaired in patients with M. tuberculosis infection, we investigated the percentage of perforin and Fas ligand (FasL) positive Vdelta2+T-cells and the possible role of activating and inhibitory natural killer (NK) cell receptors as well as that of regulatory T-cells in the control of tuberculin responsiveness.


RESULTS
Tuberculin-negative patients demonstrated decreased perforin expression and increased FasL expression, which could not be explained by dysregulation of NK cell receptor expression or altered regulatory T-cell function.


CONCLUSIONS
Altered cytotoxic capacity and apoptotic potential of Vdelta2+T-cells provide a plausible explanation for defective cellular immune functions in M. tuberculosis-infected anergic patients.
Szereday
L
L
Department of Medical Microbiology and Immunology, Pecs University Medical School, Pecs, Hungary.
Baliko
Z
Z
Szekeres-Bartho
J
J
D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism; D000943:Antigens, Differentiation / Q000378:metabolism; D060908:CTLA-4 Antigen; D003602:Cytotoxicity, Immunologic; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism; D014376:Tuberculosis / Q000276:immunology*
D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human