Expression of NKG2D ligands in multidrug-resistant nasopharyngeal carcinoma cell line CNE2/DDP and their effects on cytotoxicity of natural killer cells.
- Author:
Jia-zhuan MEI
1
;
Kun-yuan GUO
;
Hong-mei WEI
;
Chao-yang SONG
Author Information
- Publication Type:Journal Article
- MeSH: Antibodies; pharmacology; Cell Line, Tumor; Cytotoxicity, Immunologic; drug effects; immunology; Drug Resistance, Multiple; Flow Cytometry; Genotype; HLA Antigens; genetics; Histocompatibility Antigens Class I; immunology; metabolism; Humans; Killer Cells, Natural; immunology; NK Cell Lectin-Like Receptor Subfamily K; immunology; metabolism; Nasopharyngeal Neoplasms; immunology; metabolism; pathology; Polymerase Chain Reaction; Receptors, KIR; genetics
- From: Journal of Southern Medical University 2007;27(6):887-889
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo analyze the expression of NKG2D ligands on human nasopharyngeal carcinoma cell line CNE2 and the multidrug-resistant lin CNE2/DDP and investigate its impact on cytotoxicity of natural killer (NK) cells.
METHODSExpression of NKG2D ligands on the surface of CNE2 and CNE2/DDP cells was analyzed by flow cytometry, and their HLA genotypes, along with inhibitory killer cell immunoglobulin-like receptors (KIRs) expressed on NK cells from 5 healthy donors, were determined by PCR with sequence specific primers. Cytotoxicity of NK cells against CNE2 and CNE2/DDP cells was evaluated by LDH-releasing assay at different effector-to-target ratios (E:T). In blocking experiments, different monoclonal antibodies (mAb) were added to the target cells at the E:T of 20:1 ratio.
RESULTSThe HLA genotypes of CNE2 and CNE2/DDP cells were A2, 24, B18, 35, Cw4, 7, and the inhibitory KIR genotypes of the 5 healthy donors were KIR2DL1, KIR2DL3, KIR3DL1, and KIR3DL2, mismatched with the HLA -class I molecules expressed by the CNE2 and CNE2/DDP cells. The expression of MHC class I chain-related proteins A and B (MICA and MICB) on CNE2 cells was higher than that on CNE2/DDP cells (P<0.01), and ULBP1 and ULBP3 were not detectable. NK cells displayed highly in vitro cytotoxicity against CNE2 and CNE2/DDP cells with a mean cell lysis rate of (10.50-/+2.17)%, (4.98-/+0.95)%; (27.68-/+1.47) %, (15.48-/+2.10) %; (36.99-/+3.13) %, (28.46-/+4.30) %; (55.00-/+2.20) %, (40.95-/+2.21) %, respectively, corresponding to the E:T ratios of 5:1, 10:1, 20:1, and 30:1 (P<0.01). Blocking experiments confirmed that killing of CNE2 and CNE2/DDP cells by NK cells was efficiently inhibited by anti-MICA, anti-MICB, and anti-ULBP2 mAbs, whereas anti-ULBP1 and anti-ULBP3 mAbs had no effects on the cytotoxicity of the NK cells.
CONCLUSIONExpression of NKG2D ligands on CNE2 and CNE2/DDP cells is correlated with NK cell-mediated lysis, and NK cells display higher cytotoxicity against parental CNE2 cells than the multidrug-resistant CNE2/DDP cells.
