title: Regulation of APO-2 ligand/trail expression in NK cells-involvement in NK cell-mediated cytotoxicity.
abstract: Apo-2L is a new member of the tumour necrosis factor (TNF) family shown to induce apoptosis in a number of tumour cell lines. Apo-2L mRNA is expressed by numerous human tissues. Here we report that Apo-2L is expressed and utilized by human Natural Killer (NK) cells. NK cells were shown to express surface Apo-2L in response to interleukin 2 (IL-2) activation, and this response was restricted to the CD3(-)population of the NK cells. Apo-2L mRNA and intracellular Apo-2L were present in both CD3(-)and CD3(+)NK cells; however, increased expression in response to IL-2 was only observed in CD3(-)CD56(+)cells. Also, IL-2-activated NK cells were shown to utilize membrane-bound Apo-2L in mediating lysis of Jurkat cells. Furthermore, Apo-2L-induced apoptosis of Jurkat cells was more rapid than FasL-induced apoptosis, indicating an important and distinct role for Apo-2L in apoptotic cell destruction. In conclusion, we report that NK cells express Apo-2L and that IL-2 activated CD3(-)NK cells utilize the Apo-2L pathway in mediating target cell lysis.
authors.affiliation: Department of Cancer Research and Molecular Biology, Norwegian University of Science and Technology, Trondheim, Norway. Ann-Charlotte.Johnsen@medisin.ntnu.no
authors.forename: A C
authors.initials: AC
authors.lastname: Johnsen
authors.forename: J
authors.initials: J
authors.lastname: Haux
authors.forename: B
authors.initials: B
authors.lastname: Steinkjer
authors.forename: U
authors.initials: U
authors.lastname: Nonstad
authors.forename: K
authors.initials: K
authors.lastname: Egeberg
authors.forename: A
authors.initials: A
authors.lastname: Sundan
authors.forename: A
authors.initials: A
authors.lastname: Ashkenazi
authors.forename: T
authors.initials: T
authors.lastname: Espevik
mesh_terms: D000911:Antibodies, Monoclonal / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D051017:Apoptosis Regulatory Proteins; D003602:Cytotoxicity, Immunologic; D053222:Fas Ligand Protein; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D016130:Immunophenotyping; D007376:Interleukin-2 / Q000494:pharmacology; D019169:Jurkat Cells / Q000187:drug effects / Q000473:pathology; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000494:pharmacology; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000911:Antibodies, Monoclonal; D051017:Apoptosis Regulatory Proteins; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D007376:Interleukin-2; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha