The Qa-1b molecule binds to a large subpopulation of murine NK cells.
Recent studies on human NK cells have demonstrated that the NK cell CD94/NKG2 receptors bind to the nonclassical MHC class I molecule HLA-E. A functional CD94/NKG2 complex has not yet been identified in rodents, but cDNA encoding rat and mouse CD94 and NKG2 have recently been cloned, suggesting that CD94/NKG2 receptors may exist in species other than man. The mouse nonclassical MHC class I molecule Qa-1 shares several features with HLA-E. This suggests that Qa-1 may be similarly recognized by murine NK cells. To study the ability of Qa-1 to bind to murine NK cells, we have produced a soluble tetrameric form of Qa-1b. In the present study, we demonstrate that Qa-1b tetramers distinctly bind to a large subset of fresh or IL-2-activated NK1.1+/CD3- splenocytes independently of the expression of Ly49 inhibitory receptors. Binding occurs whether NK cells have evolved in an MHC class I-expressing or in an MHC class I-deficient environment. Our data suggest the existence of a Qa-1-recognizing structure on a large subpopulation of murine NK cells that may be similar to the human CD94/NKG2 heterodimeric complex.
Salcedo
M
M
Unité de Biologie Moléculaire du Gène, INSERM U277, Institut Pasteur, Paris, France. msalcedo@pasteur.fr
Bousso
P
P
Ljunggren
H G
HG
Kourilsky
P
P
Abastado
J P
JP
D000818:Animals; D015703:Antigens, CD / Q000276:immunology*; D005434:Flow Cytometry; D006680:HLA Antigens / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology*; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins / Q000276:immunology*; D051379:Mice; D051920:NK Cell Lectin-Like Receptor Subfamily D; D010455:Peptides / Q000276:immunology*; D051381:Rats; D011971:Receptors, Immunologic / Q000276:immunology; D000097625:HLA-E Antigens
D015703:Antigens, CD; D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D051920:NK Cell Lectin-Like Receptor Subfamily D; D010455:Peptides; D011971:Receptors, Immunologic; D000097625:HLA-E Antigens; C497869:KLRD1 protein, human; C497870:Klrd1 protein, mouse; C497871:Klrd1 protein, rat; C090580:Qdm protein, mouse