Related Experiment Video
Updated: Jun 20, 2026
Measurement of Natural Killer Cell-Mediated Cytotoxicity and Migration in the Context of Hepatic Tumor Cells
Published on: February 22, 2020
[Effect of demethylating treatment on cytotoxicity of NK-92MI cells]
Xiao-Ning Gao1, Li-Li Wang, Ji Lin
1Department of Hematology, Chinese PLA General Hospital, Beijing 100853, China.
Abstract:
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.
Insights
Demethylating treatment with 5-azacytidine increased inhibitory KIR expression in NK-92MI cells, leading to reduced cytotoxicity against K562 cells. This suggests a link between DNA demethylation and NK cell function.
Area of Science:
- Immunology
- Cell Biology
- Epigenetics
Context:
- Natural Killer (NK) cells are crucial for innate immunity.
- Inhibitory Killer cell immunoglobulin-like Receptors (KIRs) regulate NK cell activity.
- Epigenetic modifications, like DNA demethylation, can influence gene expression and cell function.
Purpose:
- To investigate the impact of demethylating treatment on inhibitory KIR expression and NK-92MI cell cytotoxicity.
- To explore the relationship between inhibitory KIR gene demethylation and NK cell function.
Summary:
- NK-92MI cells treated with 5-azacytidine showed increased expression of KIR3DL1, KIR2DL2/KIR2DL3, and KIR2DL1.
- This demethylation treatment resulted in decreased cytotoxicity of NK-92MI cells against K562 cells.
- KIR3DL1-positive NK-92MI cells exhibited lower cytotoxicity compared to KIR3DL1-negative cells, with no impact on cell viability.
Impact:
- Demethylating treatment suppresses NK cell cytotoxicity by upregulating inhibitory KIR expression.
- Findings provide insights into the epigenetic regulation of NK cell-mediated immunity.
- This research may inform strategies for modulating NK cell activity in therapeutic contexts.
