Gammadelta T cell activation or anergy during infections: the role of nonpeptidic TCR ligands and HLA class I molecules.
Vgamma9Vdelta2-encoded T cell receptors (TCR) expressed by most human peripheral blood gammadelta T cells mediate the recognition of nonpeptidic phosphoantigens from various pathogens without any known requirement for HLA molecules. Functionally mature Vgamma9Vdelta2 T cells display a potent natural killer (NK)-like cytotoxic activity, share with NK cells the expression of inhibitory receptors for HLA class I molecules, and release a plethora of cytokines, most notably interferon-gamma and tumor necrosis factor alpha. Hence, through local activation, the early recruitment and stimulation of Vgamma9Vdelta2 T cells may promote efficient anti-infectious immunity. However, a chronic overactivation of this T cell subset may result in immunopathology. The meeting held in St. Vincent, Val d'Aosta, Italy (symposium on gammadelta T cells in natural immunity to infections: a rationale for vaccine development organized by the World Foundation for AIDS Research and Prevention, the UNESCO, and the Italian National Research Council, December 2-4, 1996) focused on the importance of gammadelta T cell activation and anergy for the pathogenesis of tuberculosis, malaria, and HIV infections.
Poccia
F
F
Department of Biology, University of Rome Tor Vergata.
Malkovsky
M
M
Gougeon
M L
ML
Bonneville
M
M
Lopez-Botet
M
M
Fournié
J J
JJ
Colizzi
V
V
D000942:Antigens, Bacterial / Q000737:chemistry; D000953:Antigens, Protozoan / Q000737:chemistry; D017635:Clonal Anergy; D003141:Communicable Diseases / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D008024:Ligands; D008213:Lymphocyte Activation; D016131:Lymphocyte Subsets / Q000276:immunology*; D010710:Phosphates / Q000276:immunology*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000502:physiology*
D000942:Antigens, Bacterial; D000953:Antigens, Protozoan; D015395:Histocompatibility Antigens Class I; D008024:Ligands; D010710:Phosphates; D016692:Receptors, Antigen, T-Cell, gamma-delta