title: NKG2D and CD94 bind to multimeric alpha2,3-linked N-acetylneuraminic acid.
abstract: Killer lectin-like receptors on natural killer cells mediate cytotoxicity through glycans on target cells including the sialyl Lewis X antigen (sLeX). We investigated whether NK group 2D (NKG2D) and CD94 can bind to sialylated N-linked glycans, using recombinant glutathione S-transferase-fused extracellular lectin-like domains of NKG2D (rNKG2Dlec) and CD94 (rCD94lec). Both rNKG2Dlec and rCD94lec bound to plates coated with high-sLeX-expressing transferrin secreted by HepG2 cells (HepTF). The binding of rNKG2Dlec and rCD94lec to HepTF was markedly suppressed by treatment of HepTF with neuraminidase and in the presence of N-acetylneuraminic acid. Moreover, rNKG2Dlec and rCD94lec bound to alpha2,3-sialylated human alpha(1)-acid glycoprotein (AGP) but not to alpha2,6-sialylated AGP. Mutagenesis revealed that (152)Y of NKG2D and (144)F and (160)N of CD94 were critical for HepTF binding. This is the first report that NKG2D and CD94 bind to alpha2,3-sialylated but not to alpha2,6-sialylated multi-antennary N-glycans.
authors.affiliation: Department of Clinical Chemistry, School of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba 247-8510, Japan.
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Imaizumi
authors.forename: Koji
authors.initials: K
authors.lastname: Higai
authors.forename: Chiho
authors.initials: C
authors.lastname: Suzuki
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Azuma
authors.forename: Kojiro
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D015295:Antigens, Tumor-Associated, Carbohydrate / Q000737:chemistry / Q000276:immunology; D045744:Cell Line, Tumor; D006801:Humans; D016256:Lewis X Antigen / Q000737:chemistry / Q000276:immunology; D008024:Ligands; D016296:Mutagenesis; D019158:N-Acetylneuraminic Acid / Q000737:chemistry / Q000276:immunology*; D051920:NK Cell Lectin-Like Receptor Subfamily D / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D055655:NK Cell Lectin-Like Receptor Subfamily K / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D000080506:Sialyl Lewis X Antigen
chemical_list: D015295:Antigens, Tumor-Associated, Carbohydrate; C497869:KLRD1 protein, human; C527085:KLRK1 protein, human; D016256:Lewis X Antigen; D008024:Ligands; D051920:NK Cell Lectin-Like Receptor Subfamily D; D055655:NK Cell Lectin-Like Receptor Subfamily K; D000080506:Sialyl Lewis X Antigen; D019158:N-Acetylneuraminic Acid