Mycobacterium tuberculosis induces apoptosis in gamma/delta T lymphocytes from patients with advanced clinical forms of active tuberculosis.
Antigens from inactivated Mycobacterium tuberculosis H37Ra induce activation in a subpopulation of gamma/delta (gamma/delta) T lymphocytes in a manner that resembles that of superantigens from alpha/beta T cells. After culture in vitro with H37Ra proteins, gamma/delta T lymphocytes from patients with advanced clinical forms of active tuberculosis (ACF-TBC) display cytotoxic activity against homotypic target cells exposed to H37Ra. Cytotoxicity by gamma/delta T lymphocytes from ACF-TBC patients occurs in a range similar to that observed in healthy subjects. Following activation, H37Ra-stimulated gamma/delta T lymphocytes from healthy subjects did proliferate in the presence of exogenous recombinant human interleukin 2. However, under the same conditions, gamma/delta T lymphocytes from ACF-TBC patients not only did not proliferate but died by apoptosis. These results suggest that in gamma/delta T lymphocytes from patients with ACF-TBC, antigens from M. tuberculosis may induce cell activation that leads to apoptotic cell death.
Duarte
R
R
Unidad de Enfermedades Infecciosas, Hospital Universitario Reina Sofía, Córdoba, Spain.
Kindlelán
J M
JM
Carracedo
J
J
Sánchez-Guijo
P
P
Ramírez
R
R
D000942:Antigens, Bacterial / Q000276:immunology; D017209:Apoptosis / Q000276:immunology*; D002478:Cells, Cultured; D006801:Humans; D007376:Interleukin-2 / Q000276:immunology; D008213:Lymphocyte Activation; D009169:Mycobacterium tuberculosis / Q000502:physiology*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis*; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D014376:Tuberculosis / Q000276:immunology* / Q000473:pathology*; D014391:Tuberculosis, Miliary / Q000276:immunology / Q000473:pathology
D000942:Antigens, Bacterial; D007376:Interleukin-2; D016692:Receptors, Antigen, T-Cell, gamma-delta