|Title||Mapping the ligand of the NK inhibitory receptor Ly49A on living cells.|
|Publication Type||Journal Article|
|Year of Publication||2000|
|Authors||Chung, DH, Natarajan, K, Boyd, LF, Tormo, J, Mariuzza, RA, Yokoyama, WM, Margulies, DH|
|Date Published||2000 Dec 15|
|Keywords||Amino Acid Sequence, Animals, Antigens, Ly, Biotinylation, Carrier Proteins, Epitope Mapping, Epitopes, H-2 Antigens, Killer Cells, Natural, Lectins, C-Type, Ligands, Lymph Nodes, Lymphocyte Subsets, Membrane Proteins, Mice, Mice, Inbred A, Mice, Inbred BALB C, Mice, Inbred C57BL, Mice, Transgenic, Mutagenesis, Site-Directed, NK Cell Lectin-Like Receptor Subfamily A, Receptors, NK Cell Lectin-Like, Sequence Alignment, Solubility, Staining and Labeling, Tumor Cells, Cultured|
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.
|Alternate Journal||J. Immunol.|