title: Target cell-induced apoptosis of interleukin-2-activated human natural killer cells: roles of cell surface molecules and intracellular events.
abstract: We previously reported that natural killer (NK)-sensitive target cells, K562, kill interleukin-2-stimulated (lymphokine-activated killer [LAK]) but not unstimulated NK cells. We have now investigated the molecular basis of this phenomenon. Soluble monoclonal antibody (MoAb) to CD18 inhibited 75% of K562-induced DNA fragmentation and membrane disruption, whereas blocking MoAb to Fas partially inhibited only the DNA fragmentation. MoAbs to CD2, CD11a, CD11b, B7, or CD16 had limited or no effect on K562-induced death of LAK cells. Receptor ligation with either immobilized MoAb to CD18 or Fas induced membrane disruption and DNA degradation in LAK cells independently of K562, and MoAb to CD18, CD11a, or CD11b enhanced DNA fragmentation induced by anti-Fas. Fas-L-transfected Raji cells also killed LAK cells, but only if Fas-L expression was amplified. K562 cells rapidly triggered protein phosphorylation in LAK cells, and the tyrosine kinase inhibitor, Herbimycin A, inhibited DNA fragmentation and membrane disruption. Protease inhibitors strongly suppressed K562-mediated DNA fragmentation of LAK cells, but not membrane disruption. In conclusion, (1) K562-induced death of LAK cells involves primarily CD18, although other molecules, such as Fas, may also be involved; (2) K562-mediated apoptosis of LAK cells requires tyrosine phosphorylation and protease activity; (3) engagement of Fas by immobilized MoAb or Fas-L on target cells can also kill LAK cells; and (4) Fas-immobilized MoAb synergizes with coimmobilized MoAb to CD11a, CD11b, or CD18 for LAK cell killing. Activation-induced death of NK cells may represent a mechanism for NK cell regulation.
authors.affiliation: Division of Cellular and Gene Therapies, Center for Biologics Evaluation Research, Food and Drug Administration.
authors.forename: A
authors.initials: A
authors.lastname: Yamauchi
authors.forename: K
authors.initials: K
authors.lastname: Taga
authors.forename: H S
authors.initials: HS
authors.lastname: Mostowski
authors.forename: E T
authors.initials: ET
authors.lastname: Bloom
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology; D015703:Antigens, CD / Q000276:immunology / Q000502:physiology; D017209:Apoptosis / Q000187:drug effects; D016227:Benzoquinones; D018821:CD18 Antigens / Q000276:immunology / Q000502:physiology*; D002462:Cell Membrane / Q000648:ultrastructure; D003546:Cysteine Endopeptidases / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D004247:DNA / Q000032:analysis; D053222:Fas Ligand Protein; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology*; D015979:Killer Cells, Lymphokine-Activated / Q000166:cytology*; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000276:immunology; D047029:Lactams, Macrocyclic; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000473:pathology; D008228:Lymphoma, Non-Hodgkin / Q000473:pathology; D008545:Melanoma / Q000473:pathology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000502:physiology; D011480:Protease Inhibitors / Q000494:pharmacology; D011809:Quinones / Q000494:pharmacology; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017828:Rifabutin / Q000031:analogs & derivatives; D012697:Serine Endopeptidases / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured; D019014:fas Receptor / Q000502:physiology
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D016227:Benzoquinones; D018821:CD18 Antigens; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D007376:Interleukin-2; D047029:Lactams, Macrocyclic; D008562:Membrane Glycoproteins; D011480:Protease Inhibitors; D011809:Quinones; D011993:Recombinant Fusion Proteins; D019014:fas Receptor; D017828:Rifabutin; C020754:herbimycin; D004247:DNA; D012697:Serine Endopeptidases; D003546:Cysteine Endopeptidases