title: Expression of glycans linked to natural killer cell inhibition on the human zona pellucida.
abstract: Protection of the gametes from potential immune responses is a primary function in human reproduction. The primary cell type responsible for the innate immune response in the uterus is the natural killer (NK) cell. NK cells normally recognize Class I major histocompatibility (MHC) molecules on potential target cells. Since both human spermatozoa and human oocytes do not express Class I MHC molecules on their surfaces, the appropriate cell surface signal that abrogates potential NK cell-mediated responses directed against these gametes is unknown. Recent evidence indicates that surface expression of bisecting-type N-linked glycans protects cells sensitive to NK cell-mediated lysis. We report that the zona pellucida of the human egg and plasma membranes of human spermatozoa potentially bind a lectin probe specific for bisecting type glycans in a carbohydrate-dependent manner. Since the innate immune response in the uterus is primarily mediated by NK cells, our results indicate that human gametes may be protected from this response by expressing bisecting type N-linked glycans on their surfaces.
authors.affiliation: Department of Biochemistry, Eastern Virginia Medical School, Norfolk 23501, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Patankar
authors.forename: K
authors.initials: K
authors.lastname: Ozgur
authors.forename: S
authors.initials: S
authors.lastname: Oehninger
authors.forename: A
authors.initials: A
authors.lastname: Dell
authors.forename: H
authors.initials: H
authors.lastname: Morris
authors.forename: M
authors.initials: M
authors.lastname: Seppala
authors.forename: G F
authors.initials: GF
authors.lastname: Clark
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D005260:Female; D016650:Fluorescein-5-isothiocyanate; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D007108:Immune Tolerance; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000276:immunology*; D037102:Lectins / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D011134:Polysaccharides / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism*; D011247:Pregnancy; D012098:Reproduction / Q000276:immunology; D013094:Spermatozoa / Q000276:immunology / Q000378:metabolism; D015044:Zona Pellucida / Q000276:immunology* / Q000378:metabolism*
chemical_list: D015395:Histocompatibility Antigens Class I; D037102:Lectins; D011134:Polysaccharides; D016650:Fluorescein-5-isothiocyanate