title: Activating Ly-49D NK receptors: expression and function in relation to ontogeny and Ly-49 inhibitor receptors.
abstract: Developmental changes in the repertoire of activating Ly-49 family members have not been examined previously. In the present study, we have examined the expression and function of the activating Ly-49s (D and H) from birth through 8 weeks of age. We demonstrate that 1) activating Ly-49s are expressed early, 2) their expression intensity is not different from adult NK cells, and 3) activating receptors are functional. Examination of the inhibitory Ly-49s also demonstrated functional capacity immediately upon expression. To examine the kinetics of expression of the repertoire of activating Ly-49 members, we utilized five- and six-color flow cytometric analyses of NK cells from birth through adulthood. Previous studies examining the inhibitory Ly-49 repertoire have proposed that expression is regulated by the product rule. Our results indicated that Ly-49D, which recognizes H-2Dd, had a discordantly high coexpression of the inhibitory Ly-49s that recognized H-2Dd (Ly-49A and Ly-49G2). The product rule of Ly-49 expression does not explain the coexpression of selected activating and inhibitory receptors. This high level of coexpression of H-2Dd recognizing activating and inhibitory Ly-49s suggests an in vivo selection or regulated coexpression.
authors.affiliation: Laboratory of Experimental Immunology, DBS, National Cancer Institute-FCRDC, Frederick, Maryland 21702-1201, USA. Ortaldo@mail.ncifcrf.gov
authors.forename: J R
authors.initials: JR
authors.lastname: Ortaldo
authors.forename: R
authors.initials: R
authors.lastname: Winkler-Pickett
authors.forename: G
authors.initials: G
authors.lastname: Wiegand
mesh_terms: D000818:Animals; D000950:Antigens, Ly / Q000096:biosynthesis / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D005434:Flow Cytometry; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis; D006128:Growth / Q000502:physiology; D007371:Interferon-gamma / Q000096:biosynthesis; D007694:Killer Cells, Natural / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D037181:Lectins, C-Type; D016131:Lymphocyte Subsets / Q000378:metabolism / Q000502:physiology; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D011971:Receptors, Immunologic / Q000096:biosynthesis / Q000502:physiology*; D055630:Receptors, NK Cell Lectin-Like; D013601:T-Lymphocytes / Q000378:metabolism / Q000502:physiology
chemical_list: D000950:Antigens, Ly; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D055630:Receptors, NK Cell Lectin-Like; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D002118:Calcium