RT Journal Article
SR Electronic
T1 NK Cell CD94/NKG2A Inhibitory Receptors Are Internalized and Recycle Independently of Inhibitory Signaling Processes
JF The Journal of Immunology
JO J. Immunol.
FD American Association of Immunologists
SP 6102
OP 6111
DO 10.4049/jimmunol.169.11.6102
VO 169
IS 11
A1 Borrego, Francisco
A1 Kabat, Juraj
A1 Sanni, Tolib B.
A1 Coligan, John E.
YR 2002
UL http://www.jimmunol.org/content/169/11/6102.abstract
AB Human CD94/NKG2A is an inhibitory receptor that recognizes HLA-E and is expressed by NK cells and a subset of T cells. We have analyzed the cellular trafficking of the CD94/NKG2A receptor using the NKL cell line and peripheral blood NK cells. Flow cytometric, confocal microscopic, and biochemical analyses show that CD94/NKG2A continuously recycles in an active process that requires the cytoskeleton between the cell surface and intracellular compartments that are distinguishable from recycling compartments used by well-characterized receptors, such as transferrin receptor (CD71). CD94/NKG2A, an inhibitory receptor, traffics differently from the closely related CD94/NKG2C molecule, an activating receptor. Using transfection/expression analyses of wild-type and mutant CD94/NKG2A molecules in the HLA-E negative rat basophilic cell line RBL-2H3, we demonstrate that CD94/NKG2A internalization is independent of ligand cross-linking or the presence of functional immunoreceptor tyrosine-based inhibition motifs. Thus, the mechanisms that control cell surface homeostasis of CD94/NKG2A are independent of functional signaling.