The lectin-like NK cell receptor Ly-49A recognizes a carbohydrate-independent epitope on its MHC class I ligand

Immunity. 1998 Feb;8(2):245-54. doi: 10.1016/s1074-7613(00)80476-8.

Abstract

The mouse NK inhibitory Ly-49A receptor specifically interacts with a peptide-induced conformational determinant on its MHC class I ligand, H-2Dd. In addition, it binds the polysaccharide fucoidan, consistent with its C-type lectin homology and the hypothesis that Ly-49A interacts with carbohydrates on Dd. Herein, however, we demonstrate that Ly-49A recognizes Dd mutants lacking N-glycosylation. Fucoidan competes for binding with anti-Ly-49A antibodies that inhibit Ly-49A-Dd interaction, and blocks apparent Ly-49A binding to unglycosylated Dd. We confirm that Ly-49A recognizes the alpha1 and amino-terminal alpha2 domains of Dd by analysis of recombinant H-2Kd-H-2Dd molecules. These studies indicate that Ly-49A recognizes carbohydrate-independent epitope(s) on Dd and suggest that Ly-49A has two distinct ligands, carbohydrate and MHC class I.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigens, Ly*
  • Binding, Competitive
  • Carrier Proteins / immunology*
  • Carrier Proteins / metabolism
  • Cytotoxicity Tests, Immunologic
  • Epitopes
  • Glycoproteins / chemistry
  • Glycoproteins / genetics
  • Glycoproteins / immunology*
  • Glycoproteins / metabolism
  • Glycosylation
  • H-2 Antigens / chemistry
  • H-2 Antigens / genetics
  • H-2 Antigens / immunology*
  • H-2 Antigens / metabolism
  • Histocompatibility Antigen H-2D
  • Killer Cells, Lymphokine-Activated / immunology
  • Killer Cells, Natural / immunology*
  • Lectins / immunology*
  • Lectins / metabolism
  • Lectins, C-Type
  • Ligands
  • Membrane Proteins / immunology*
  • Membrane Proteins / metabolism
  • Mice
  • Models, Molecular
  • Mutation
  • Polysaccharides / metabolism
  • Protein Binding
  • Receptors, Immunologic / immunology*
  • Receptors, Immunologic / metabolism
  • Receptors, NK Cell Lectin-Like

Substances

  • Antigens, Ly
  • Carrier Proteins
  • Epitopes
  • Glycoproteins
  • H-2 Antigens
  • H-2K(K) antigen
  • Histocompatibility Antigen H-2D
  • Lectins
  • Lectins, C-Type
  • Ligands
  • Membrane Proteins
  • Polysaccharides
  • Receptors, Immunologic
  • Receptors, NK Cell Lectin-Like
  • fucoidan