title: IFNγ production by NK cells from HLA-sensitized patients after in vitro exposure to allo-antigens.
abstract: Using a novel cytokine flow cytometry test (allo-CFC), we have previously shown that incubation of allogeneic cells with peripheral blood from highly-HLA sensitized (HS) patients results in reproducible gamma-interferon (IFNγ production in CD3(-) cells, and high (+) allo-CFC levels correlated with risk for antibody-mediated rejection (AMR). Here we report on identification of the cells and mechanisms responsible. The allo-CFC with/without modification was performed using blood from HS or normal individuals. IFNγ producing cells were CD3(-)/CD19(-), but CD3(-)/CD56(+). In vitro and in vivo B cell-depletion did not affect IFNγ production, demonstrating NK cells as the cells responsible for IFNγ production. NK cells from allo-CFC(+) or (-) individuals released significant amounts of IFNγ against target cells treated with serum from allo-CFC(+) individuals, but not allo-CFC(-) individuals. IFNγ release was abrogated by protein A/G treatment of the pretreated target cells, suggesting mediation by antibodies via FcγRIIIa (CD16). In conclusion, NK cell IFNγ release after allo-antigen exposure is mediated primarily through antibody-dependent cellular cytotoxicity (ADCC)-like mechanisms, suggesting that NK cells may be partially responsible for graft injury during AMR including C4d(-) AMR via ADCC, and could be a potential target for modification of this process.
authors.affiliation: Transplant Immunology Laboratory, Cedars-Sinai Medical Center/UCLA School of Medicine, 8723 Alden Dr., Steven Spielberg Bldg., Los Angeles, CA 90048, USA. Mieko.Toyoda@cshs.org
authors.forename: M
authors.initials: M
authors.lastname: Toyoda
authors.forename: S
authors.initials: S
authors.lastname: Ge
authors.forename: E
authors.initials: E
authors.lastname: Suviolahti
authors.forename: P
authors.initials: P
authors.lastname: Pichurin
authors.forename: B
authors.initials: B
authors.lastname: Shin
authors.forename: A
authors.initials: A
authors.lastname: Pao
authors.forename: A
authors.initials: A
authors.lastname: Vo
authors.forename: N
authors.initials: N
authors.lastname: Deer
authors.forename: A
authors.initials: A
authors.lastname: Aguiluz
authors.forename: A
authors.initials: A
authors.lastname: Karasyov
authors.forename: S C
authors.initials: SC
authors.lastname: Jordan
mesh_terms: D015703:Antigens, CD / Q000276:immunology* / Q000378:metabolism; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D005260:Female; D006680:HLA Antigens / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology*; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D008297:Male
chemical_list: D015703:Antigens, CD; D006680:HLA Antigens; D007371:Interferon-gamma