Effect of IL-2 and IL-15 on expression of KIR3DL1 and NKG2D in natural killer cells

Objective To study the effect of IL-2 and IL-15 on expression of KIR3DL1 and NKG2D in human peripheral blood derived natural killer（NK） cells. Methods NK cells were isolated from PBMNC using mini-magnetic cell-selection（MACS） and NK cell isolation kit（Miltenyi Biotec,Germany）,and cultured with stem cell growth medium（SCGM） supplemented with 5% human AB serum in combination with of IL-2 and IL-15 for 15 days.Cytotoxicity to target K562 cells was evaluated,and expression of KIR3DL1（CD158e） and NKG2D in NK cells was analyzed by flow cytometry. Results The cytotoxicity of NK cells was significantly higher after culture than before culture（P＜0.01）.The expression rate of KIR3DL1 in NK cells was about 10% lower after culture than before culture（P＜0.05）.No significant difference was found in expression of NKG2D,which was 99% before and after culture. Conclusion The cytotoxicity of NK cells after a long time in vitro culture with IL2 and IL15 significantly increases and down-regulates the expression of KIR3DL1