Fig. 3

25KbPEI-mediated calcium influx induces activation of ERK and mTOR signaling pathways and increases IFN-γ production. A, B Phosphorylation of ERK and mTOR in 25KbPEI-treated NK-92MI cells cultured in calcium-free culture medium; p-ERK and p-mTOR were quantified by flow cytometry. C IFN-γ production by 25KbPEI-treated NK-92MI cells cultured in calcium-free culture medium; IFN-γ levels in the cytosol were measured by flow cytometry. D, E Phosphorylation of ERK and mTOR in 25KbPEI-treated NK-92MI cells cultured in the presence of a TRPM2 inhibitor, 2-APB (100 μM). p-ERK and p-mTOR were quantified by flow cytometry. F IFN-γ production by 25KbPEI-treated NK-92MI cells cultured in the presence of 2-APB (100 μM). IFN-γ levels in the cytosol were measured by flow cytometry. Statistical analysis was conducted using one-way ANOVA with Tukey’s multiple comparisons test. *P < 0.05; **P < 0.01; ***P < 0.001, and ****P < 0.0001