title: Killer Ig-like receptor 2DL4 does not mediate NK cell IFN-γ responses to soluble HLA-G preparations.
abstract: The MHC class Ib molecule HLA-G has previously been reported to be the ligand for the NK cell receptor killer Ig-like receptor (KIR)2DL4, but this remains controversial. In this study, we investigated IFN-γ production by freshly isolated NK cells in response to both soluble and solid-phase ligands, including anti-KIR2DL4 mAbs and rHLA-G. Although freshly isolated CD56(bright) NK cells produced IFN-γ in response to soluble HLA-G preparations, the response was found to be absolutely dependent on the presence of small numbers of contaminating CD56(-), CD14(-), CD11c(+) myeloid dendritic cells (mDCs). HLA-G tetramers bound only to the contaminating mDCs in the NK preparations, and Abs to KIR2DL4 and HLA-G did not block NK cell IFN-γ production. NK cells did not respond to plate-bound HLA-G. Freshly isolated NK cells also produced IFN-γ in response to unpurified soluble anti-KIR2DL4 mAb but not to low endotoxin affinity-purified Ab. The data suggest that previous reports of functional interactions between KIR2DL4 and HLA-G may have resulted from the use of purified NK cells that were contaminated with mDCs and HLA-G preparations that were contaminated with material capable of stimulating mDCs to produce cytokines that stimulate NK cells to produce IFN-γ.
authors: Department of Clinical Immunology, Royal Perth Hospital, Perth, Western Australia 6000, Australia;
authors: Michael E L
authors: ME
authors: Le Page
authors: Jodie P
authors: JP
authors: Goodridge
authors: Elisabeth
authors: E
authors: John
authors: Frank T
authors: FT
authors: Christiansen
authors: Campbell S
authors: CS
authors: Witt
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D059951:HLA-G Antigens / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology* / Q000378:metabolism; D018664:Interleukin-12 / Q000276:immunology / Q000378:metabolism; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000276:immunology / Q000378:metabolism; D022423:Myeloid Cells / Q000276:immunology / Q000378:metabolism; D011971:Receptors, Immunologic / Q000276:immunology / Q000378:metabolism; D054345:Receptors, KIR2DL4 / Q000276:immunology* / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D059951:HLA-G Antigens; C491341:LILRB2 protein, human; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D054345:Receptors, KIR2DL4; D018664:Interleukin-12; D007371:Interferon-gamma