Mapping the ligand of the NK inhibitory receptor Ly49A on living cells.
We have used a recombinant, biotinylated form of the mouse NK cell inhibitory receptor, Ly49A, to visualize the expression of MHC class I (MHC-I) ligands on living lymphoid cells. A panel of murine strains, including MHC congenic lines, was examined. We detected binding of Ly49A to cells expressing H-2D(d), H-2D(k), and H-2D(p) but not to those expressing other MHC molecules. Cells of the MHC-recombinant strain B10.PL (H-2(u)) not only bound Ly49A but also inhibited cytolysis by Ly49A(+) effector cells, consistent with the correlation of in vitro binding and NK cell function. Binding of Ly49A to H-2D(d)-bearing cells of different lymphoid tissues was proportional to the level of H-2D(d) expression and was not related to the lineage of the cells examined. These binding results, interpreted in the context of amino acid sequence comparisons and the recently determined three-dimensional structure of the Ly49A/H-2D(d) complex, suggest a role for amino acid residues at the amino-terminal end of the alpha1 helix of the MHC-I molecule for Ly49A interaction. This view is supported by a marked decrease in affinity of an H-2D(d) mutant, I52 M, for Ly49A. Thus, allelic variation of MHC-I molecules controls measurable affinity for the NK inhibitory receptor Ly49A and explains differences in functional recognition in different mouse strains.
Chung
D H
DH
Molecular Biology Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Natarajan
K
K
Boyd
L F
LF
Tormo
J
J
Mariuzza
R A
RA
Yokoyama
W M
WM
Margulies
D H
DH
D000595:Amino Acid Sequence; D000818:Animals; D000950:Antigens, Ly; D019921:Biotinylation; D002352:Carrier Proteins / Q000032:analysis / Q000378:metabolism*; D018604:Epitope Mapping / Q000379:methods*; D000939:Epitopes / Q000032:analysis; D006183:H-2 Antigens / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D064532:Histocompatibility Antigen H-2D; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism*; D037181:Lectins, C-Type; D008024:Ligands; D008198:Lymph Nodes / Q000737:chemistry / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D016131:Lymphocyte Subsets / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D008565:Membrane Proteins / Q000032:analysis / Q000378:metabolism*; D051379:Mice; D008805:Mice, Inbred A; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D016297:Mutagenesis, Site-Directed; D055650:NK Cell Lectin-Like Receptor Subfamily A; D055630:Receptors, NK Cell Lectin-Like; D016415:Sequence Alignment; D012995:Solubility; D013194:Staining and Labeling / Q000379:methods; D014407:Tumor Cells, Cultured
D000950:Antigens, Ly; D002352:Carrier Proteins; D000939:Epitopes; D006183:H-2 Antigens; D064532:Histocompatibility Antigen H-2D; C527088:Klra1 protein, mouse; D037181:Lectins, C-Type; D008024:Ligands; D008565:Membrane Proteins; D055650:NK Cell Lectin-Like Receptor Subfamily A; D055630:Receptors, NK Cell Lectin-Like