Inhibition Effect of Acid Environment on Cytotoxicity of Cytokine-induced Killer Cells Against Hepatocellular Carcinoma Cells HepG2

Objective  To investigate the effect of acid environment on the cytotoxicity of cytokine-induced killer(CIK) cells against hepatocellular carcinoma cells HepG2.

Methods  CIK cells were induced from peripheral blood mononuclear cells with IFN-γ, IL-2 and CD3 mAb. HepG2 cells and luciferase marked HepG2 cells (HepG2-luc) were co-cultured with CIK cells at different effect/target ratios, and the medium were adjusted at pH6.5 and pH7.4 respectively. The luciferase intensity of HepG2-luc was detected with IVIS Spectrum System, and the cytotoxicity was calculated according to luciferase intensity and MTT assay. HepG2 cells were cultured with the medium including 0, 50% and 100% CIK at pH6.5 and pH7.4 respectively. The apoptosis and necrotic cells percentage were detected by flow cytometry.

Results  The cytotoxicity of CIK cells at pH7.4 were significantly higher than that at pH6.5. Also, in CIK condition medium, the percentage of apoptosis and necrotic HepG2 cells at pH7.4 condition was significantly higher than that at pH6.5.

Conclusion  Acid environment markedly inhibits the cytotoxicity of CIK cells against hepatocellular carcinoma cells HepG2.