Ly-49W, an Activating Receptor of Nonobese Diabetic Mice With Close Homology to the Inhibitory Receptor Ly-49G, Recognizes H-2Dk and H-2Dd

• Published in: The Journal of immunology (1950) Vol. 166; no. 4; pp. 2333 - 2341
• Main Authors: Silver, Elizabeth T, Gong, Dong-Er, Hazes, Bart, Kane, Kevin P
• Format: Journal Article
• Language: English
• Published: Am Assoc Immnol 15.02.2001
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.166.4.2333

Abstract The diversity and ligand specificity of activating Ly-49 receptors expressed by murine NK cells are largely unknown. We cloned a new Ly-49-activating receptor, expressed by NK cells of the nonobese diabetic mouse strain, which we have designated Ly-49W. Ly-49W is highly related to the known inhibitory receptor Ly-49G in its carbohydrate recognition domain, exhibiting 97.6% amino acid identity in this region. We demonstrate that the 4D11 and Cwy-3 Abs, thought to be Ly-49G specific, also recognize Ly-49W. Rat RNK-16 cells transfected with Ly-49W mediated reverse Ab-dependent cellular cytotoxicity of FcR-positive target cells, indicating that Ly-49W can activate NK-mediated lysis. We further show that Ly-49W is allo-MHC specific: Ly-49W transfectants of RNK-16 only lysed Con A blasts expressing H-2k or H-2d haplotypes, and Ab-blocking experiments indicated that H-2Dk and Dd are ligands for Ly-49W. Ly-49W is the first activating Ly-49 receptor demonstrated to recognize an H-2k class I product. Ly-49G and Ly-49W represent a new pair of NK receptors with very similar ligand-binding domains, but opposite signaling functions.