title: Tumor necrosis factor and lymphotoxin secretion by human natural killer cells leads to antiviral cytotoxicity.
abstract: NK cells mediate their cytotoxicity against tumor cells through abroad array of cytotoxic and cytostatic proteins. We investigated whether specific proteins could also be identified that contributed to NK cell-mediated antiviral immunity. Human CD16+/CD3- NK cells were obtained by using FACS and subsequently cloned by using limiting dilution. These NK cell lines, which were cytotoxic against NK-sensitive tumor targets and virally infected cells, also generated supernatants that selectively killed vesicular stomatitis virus-infected cells while sparing noninfected cells. This soluble antiviral activity was completely neutralized by antibodies specific for TNF and lymphotoxin. Purified human rTNF also duplicated this specific cytotoxicity against vesicular stomatitis virus-infected cells, as well as against CMV-, Theiler's murine encephalomyelitis virus-, and HSV-infected cells. The degree of cytotoxicity varied for the different viruses and depended on the cell type infected. These results suggest that NK cells can mediate selective and direct cytotoxicity against virally infected cells by the secretion of TNF and lymphotoxin.
authors.affiliation: Department of Immunology, Mayo Clinic and Foundation, Rochester, MN 55905.
authors.forename: C V
authors.initials: CV
authors.lastname: Paya
authors.forename: N
authors.initials: N
authors.lastname: Kenmotsu
authors.forename: R A
authors.initials: RA
authors.lastname: Schoon
authors.forename: P J
authors.initials: PJ
authors.lastname: Leibson
mesh_terms: D002460:Cell Line; D002474:Cell-Free System; D002999:Clone Cells / Q000276:immunology / Q000378:metabolism; D003588:Cytopathogenic Effect, Viral / Q000187:drug effects; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007106:Immune Sera / Q000494:pharmacology; D007371:Interferon-gamma / Q000096:biosynthesis; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism*; D008233:Lymphotoxin-alpha / Q000096:biosynthesis* / Q000276:immunology / Q000633:toxicity; D009500:Neutralization Tests; D013045:Species Specificity; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000276:immunology / Q000633:toxicity; D014721:Vesicular stomatitis Indiana virus / Q000187:drug effects / Q000276:immunology; D014779:Virus Replication / Q000187:drug effects
chemical_list: D007106:Immune Sera; D008233:Lymphotoxin-alpha; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma