Allelic exclusion of Ly49-family genes encoding class I MHC-specific receptors on NK cells.
An important feature of natural killer (NK) cell activity is the lysis of cells that have extinguished expression of some or all class I major histocompatibility (MHC) molecules. Accordingly, the Ly49A NK-cell antigen receptor has been shown to deliver an inhibitory signal to NK cells on encounter with Dd or Dk class I MHC on target cells. Ly49A belongs to a family of eight or more highly related, tightly linked genes. Expression of Ly49A and Ly49C, another member of the Ly49 family with distinct MHC specificity, define subpopulations of NK cells that are only partly overlapping. The mechanisms regulating the expression of LY49 family members are unknown. We show here that the Ly49A and Ly49C NK-cell receptors are each subject to allelic exclusion. Because Ly49 genes are not thought to undergo DNA rearrangement, allelic exclusion of Ly49 genes could involve a mechanism distinct from that used by B and T lymphocytes and is likely to play an important role in the genesis of a putative NK-cell repertoire specific for class I molecules.
Held
W
W
Department of Molecular and Cell Biology, University of California, Berkeley 94720, USA.
Roland
J
J
Raulet
D H
DH
D000483:Alleles; D000818:Animals; D000950:Antigens, Ly; D001483:Base Sequence; D002478:Cells, Cultured; D003001:Cloning, Molecular; D017931:DNA Primers; D015395:Histocompatibility Antigens Class I / Q000235:genetics* / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008969:Molecular Sequence Data; D055650:NK Cell Lectin-Like Receptor Subfamily A; D011971:Receptors, Immunologic / Q000235:genetics* / Q000276:immunology; D055630:Receptors, NK Cell Lectin-Like
D000950:Antigens, Ly; D017931:DNA Primers; D015395:Histocompatibility Antigens Class I; C527088:Klra1 protein, mouse; C527091:Klra3 protein, mouse; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D055650:NK Cell Lectin-Like Receptor Subfamily A; D011971:Receptors, Immunologic; D055630:Receptors, NK Cell Lectin-Like