Phosphoantigen activation induces surface translocation of intracellular CD94/NKG2A class I receptor on CD94- peripheral Vgamma9 Vdelta2 T cells but not on CD94- thymic or mature gammadelta T cell clones.
Most adult peripheral blood gammadelta T cells express Vgamma9/Vdelta2-encoded TCR that recognize a restricted set of nonpeptidic phosphorylated compounds, referred to as phosphoantigens. They also express various MHC class I-specific inhibitory receptors (IR), in particular CD94/ NKG2-A heterodimers, which participate in the fine tuning of their TCR-mediated activation threshold. Most mature Vgamma9/Vdelta2 T cells express surface CD94 receptors, unlike cord blood or thymus-derived Vgamma9/Vdelta2 clones, thus suggesting a role for the microenvironment in IR expression. In the present study we show that most CD94- Vgamma9Vdelta2 PBL ex vivo express an intracellular pool of CD94/NKG2-A receptors that is translocated to the cell surface upon activation by phosphoantigens or IL-2. In stark contrast, intracellular CD94/NKG2-A complexes are undetectable in CD94- thymus or PBL-derived mature Vdelta2 T cell clones, and no surface induction is observed following phosphoantigen activation of T cell clones. Altogether these results provide new insights into the regulation of CD94/NKG2-A expression on T lymphocytes and suggest the existence of distinct mechanisms controlling in vivo and in vitro induction of IR on these cells.
Boullier
S
S
Unité d'Oncologie Virale, Département SIDA et Rétrovirus, Institut Pasteur, Paris, France.
Poquet
Y
Y
Halary
F
F
Bonneville
M
M
Fournie
J J
JJ
Gougeon
M L
ML
D000818:Animals; D000941:Antigens / Q000276:immunology*; D015703:Antigens, CD / Q000032:analysis / Q000378:metabolism*; D001692:Biological Transport; D006801:Humans; D037181:Lectins, C-Type; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000032:analysis / Q000378:metabolism*; D051379:Mice; D051920:NK Cell Lectin-Like Receptor Subfamily D; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis*; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D000941:Antigens; D015703:Antigens, CD; C497869:KLRD1 protein, human; C497870:Klrd1 protein, mouse; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D051920:NK Cell Lectin-Like Receptor Subfamily D; D016692:Receptors, Antigen, T-Cell, gamma-delta; D014409:Tumor Necrosis Factor-alpha