title: Preferential survival of CD8 T and NK cells expressing high levels of CD94.
abstract: The Qa-1(b)/Qdm tetramer binds to CD94/NKG2 receptors expressed at high levels on approximately 50% of murine NK cells. Although very few CD8 T cells from naive mice express CD94/NKG2 receptors, approximately 50% of CD8 T cells taken from mice undergoing a secondary response against Listeria monocytogenes (LM) are CD94(high) and bind the tetramer. Although CD94(int) NK cells do not bind the tetramer, CD94(int) CD8 T cells do, and this binding is dependent on the CD8 coreceptor. We found that the extent of apoptosis in CD8 T and NK cells was inversely related to the expression of CD94, with lower levels of apoptosis seen in CD94(high) cells after 1-3 days of culture. The difference in CD8 T cell survival was evident as early as 6 h after culture and persisted until nearly all the CD94(neg/int) cells were apoptotic by 48 h. In contrast, expression of inhibitory Ly-49A,G2,C/I molecules was associated with higher levels of apoptosis. Cross-linking CD94/NKG2 receptors on CD8 T cells from a mouse undergoing an LM infection further reduced the percentage of apoptotic cells on the CD94-expressing populations, while cross-linking Ly-49I had no effect on CD8 T cells expressing Ly-49I. Cross-linking CD3 on CD8 T cells from a mouse undergoing a secondary LM infection increases the extent of apoptosis, but this is prevented by cross-linking CD94/NKG2 receptors at the same time. Similar results were observed with NK cells in that the CD94(high) population displayed less apoptosis than CD94(int) cells after 1-3 days in culture. Therefore, the expression of CD94/NKG2 is correlated with a lower level of apoptosis and may play an important role in the maintenance of CD8 T and NK cells.
authors.affiliation: Center for Immunology, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX 75390-9093, USA.
authors.forename: Anasuya
authors.initials: A
authors.lastname: Gunturi
authors.forename: Rance E
authors.initials: RE
authors.lastname: Berg
authors.forename: James
authors.initials: J
authors.lastname: Forman
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D015703:Antigens, CD / Q000096:biosynthesis* / Q000276:immunology / Q000378:metabolism; D000950:Antigens, Ly / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism; D017209:Apoptosis / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D002470:Cell Survival / Q000276:immunology; D002478:Cells, Cultured; D003432:Cross-Linking Reagents / Q000378:metabolism; D007694:Killer Cells, Natural / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D037181:Lectins, C-Type / Q000096:biosynthesis* / Q000276:immunology / Q000378:metabolism; D008089:Listeria monocytogenes / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D051920:NK Cell Lectin-Like Receptor Subfamily D; D011971:Receptors, Immunologic / Q000096:biosynthesis* / Q000276:immunology / Q000378:metabolism; D011975:Receptors, Mitogen / Q000096:biosynthesis* / Q000276:immunology / Q000378:metabolism; D055630:Receptors, NK Cell Lectin-Like; D055607:Receptors, Natural Killer Cell
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000950:Antigens, Ly; D003432:Cross-Linking Reagents; C497870:Klrd1 protein, mouse; D037181:Lectins, C-Type; D051920:NK Cell Lectin-Like Receptor Subfamily D; D011971:Receptors, Immunologic; D011975:Receptors, Mitogen; D055630:Receptors, NK Cell Lectin-Like; D055607:Receptors, Natural Killer Cell