title: An autosomal dominant locus, Nka, mapping to the Ly-49 region of a rat natural killer (NK) gene complex, controls NK cell lysis of allogeneic lymphocytes.
abstract: Natural Killer (NK) cells can recognize and kill MHC-incompatible normal bone marrow-derived cells. Presently characterized MHC-binding receptors on NK cells, including the Ly-49 family in the mouse, transmit inhibitory signals upon binding to cognate class I MHC ligands. Here we study in vivo NK-mediated lysis of normal allogeneic lymphocytes in crosses between alloreactivity-competent PVG rats and alloreactivity-deficient DA rats. NK cells from both strains are able to lyse standard tumor targets. We identify an autosomal dominant locus, Nka, that controls NK-mediated alloreactivity. Individuals carrying the dominant PVG allele in single dose were fully competent in eliminating allogeneic target cells, suggesting that Nka encodes or regulates a gene product inducing or activating alloreactivity. By linkage analysis and pulsed field gel electrophoresis, a natural killer gene complex (NKC) on rat chromosome 4 is described that contains the rat NKR-P1 and Ly-49 multigene families plus a rat NKG2D homologue. Nka maps within the NKC, together with the most telomeric Ly-49 family members, but separate from NKG2D and the NKR-P1 family. The Nka-encoded response, moreover, correlates with the expression of transcripts for Ly-49 receptors in NK cell populations, as Northern blot analysis demonstrated low expression of Ly-49 genes in DA NK cells, in contrast to high expression in alloreactivity-competent PVG, (DA X PVG)F1, and PVG.1AVI NK cells. The low Ly-49 expression in DA is not induced by MHC haplotype, as demonstrated by high expression of Ly-49 in the DA MHC-congenic PVG.1AVI strain. Finally, we have cloned and characterized the first four members of the rat Ly-49 gene family. Their cytoplasmic domains demonstrate substantial heterogeneity, consistent with the hypothesis that different Ly-49 family members may subserve different signaling functions.
authors.affiliation: Department of Anatomy, University of Oslo, Norway.
authors.forename: E
authors.initials: E
authors.lastname: Dissen
authors.forename: J C
authors.initials: JC
authors.lastname: Ryan
authors.forename: W E
authors.initials: WE
authors.lastname: Seaman
authors.forename: S
authors.initials: S
authors.lastname: Fossum
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000950:Antigens, Ly; D000954:Antigens, Surface / Q000276:immunology; D001483:Base Sequence; D002874:Chromosome Mapping; D016384:Consensus Sequence; D003433:Crosses, Genetic; D017931:DNA Primers; D005091:Exons; D005799:Genes, Dominant; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D007519:Isoantigens / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D037181:Lectins, C-Type; D008285:Major Histocompatibility Complex; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011544:Pseudogenes; D051381:Rats; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D011919:Rats, Inbred Strains; D055630:Receptors, NK Cell Lectin-Like; D017386:Sequence Homology, Amino Acid
chemical_list: D000950:Antigens, Ly; D000954:Antigens, Surface; D017931:DNA Primers; D015395:Histocompatibility Antigens Class I; D007519:Isoantigens; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D055630:Receptors, NK Cell Lectin-Like