[Effect of demethylating treatment on cytotoxicity of NK-92MI cells].
In order to investigate the effect of demethylating treatment on the expression of inhibitory KIR and the cytolytic activity of NK-92MI cells, and to study the possible relationship between the demethylation of inhibitory kir gene and the function of NK cells. NK-92MI cells were treated with 5-azacytidine to induce DNA demethylation. The expression of KIR3DL1, KIR2DL2/KIR2DL3, KIR2DL1 and the viability of NK-92MI cells were detected by flow cytometry. The KIR3DL1 positive and the KIR3DL1 negative NK-92MI cells were also sorted by flow cytometry. The cytotoxicity of NK-92MI against K562 cells was detected by the LDH release assay. The results demonstrated that the expressions of KIR3DL1, KIR2DL2/KIR2DL3 and KIR2DL1 in NK-92MI cells all increased after treating with 1.0, 2.5 and 5 micromol/L of 5-azacytidine for 72 hours. And the cytotoxicity of NK-92MI against K562 cells decreased. In these dose range, 5-azacytidine did not influence the viability of NK-92MI cells. Additionally, the cytotoxicity of KIR3DL1 positive NK-92MI cells was lower than that of the KIR3DL1 negative cells. It is concluded that the demethylating treatment suppresses the cytotoxicity of NK-92MI cells through increasing the expression of inhibitory KIR.
Gao
Xiao-Ning
XN
Department of Hematology, Chinese PLA General Hospital, Beijing 100853, China.
Wang
Li-Li
LL
Lin
Ji
J
Yu
Li
L
D003602:Cytotoxicity, Immunologic / Q000276:immunology*; D019175:DNA Methylation; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D006801:Humans; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism*; D054342:Receptors, KIR2DL1 / Q000378:metabolism; D054344:Receptors, KIR2DL3 / Q000378:metabolism; D054341:Receptors, KIR3DL1 / Q000378:metabolism; D054347:Receptors, KIR3DL2 / Q000378:metabolism
C093100:KIR2DL1 protein, human; C515078:KIR2DL3 protein, human; D054342:Receptors, KIR2DL1; D054344:Receptors, KIR2DL3; D054341:Receptors, KIR3DL1; D054347:Receptors, KIR3DL2