title: Characterization of three new membrane structures on rat NK cells which are involved in activation of the lytic machinery.
abstract: In this study, three membrane structures on rat NK cells which activate lysis of target cells were characterized. Furthermore, the role of adhesion molecules in this activation process, in particular the CD18-associated integrins, was investigated. Three rat NK-activation structures were identified which have not been previously described. These structures are apparently unique as they differed in molecular weight from known NK-activation structures. Cross-linking of these activation structures with specific mAbs and a Fc gamma R-positive tumor cell line (P815) resulted in enhanced killing of these target cells by NK cells. If the CD18-associated integrins were masked by the anti-CD18 mAb WT.3, the redirected killing of P815 was completely blocked. This indicates that the CD18-associated integrins play a crucial role in activation of NK cells. Furthermore, our results show that rat NK cells possess multiple activation structures.
authors.affiliation: Department of Pathology, Leiden University, The Netherlands.
authors.forename: K M
authors.initials: KM
authors.lastname: Giezeman-Smits
authors.forename: A
authors.initials: A
authors.lastname: Gorter
authors.forename: J F
authors.initials: JF
authors.lastname: Nagelkerke
authors.forename: R L
authors.initials: RL
authors.lastname: van Vlierberghe
authors.forename: J
authors.initials: J
authors.lastname: van Eendenburg
authors.forename: A M
authors.initials: AM
authors.lastname: Eggermont
authors.forename: G J
authors.initials: GJ
authors.lastname: Fleuren
authors.forename: P J
authors.initials: PJ
authors.lastname: Kuppen
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology; D001402:B-Lymphocytes / Q000276:immunology; D018821:CD18 Antigens / Q000276:immunology; D002462:Cell Membrane / Q000276:immunology / Q000648:ultrastructure*; D003602:Cytotoxicity, Immunologic / Q000502:physiology*; D016023:Integrins / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology* / Q000648:ultrastructure; D008213:Lymphocyte Activation; D051381:Rats; D017452:Receptors, IgG / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D018821:CD18 Antigens; D016023:Integrins; D017452:Receptors, IgG