Fig. 3.

Activation of NK cells by type I IFNs induced from HVJ-E-stimulated DCs. a Intratumor expression of type I IFN mRNAs after in vivo injection of HVJ-E or saline injection measured by quantitative real-time RT-PCR (n = 5/group). This experiment was repeated four times with similar results. b Type I IFNs in the conditioned medium of Renca cells cultured with HVJ-E in the presence or absence of DCs. HVJ-E was added at an MOI of 0.3–3,000. Both IFN-α and IFN-β levels were increased in an HVJ-E-dose-dependent manner (*P < 0.05, **P < 0.01) only in the cultures with DCs. Data points are the mean ± SE of triplicate wells. This experiment was repeated three times with similar results. c A significant increase of IFN-γ was observed in the culture medium of Renca cells after addition of H-DCCM and NK cells (*P < 0.01), while no significant increase of IFN-γ secretion was detected with either HVJ-E or H-DCCM alone. Data points are the mean ± SE of triplicate wells. This experiment was repeated three times with similar results. d IFN-γ secretion was reduced by anti-IFNAR2 in the medium of Renca cells cultured with H-DCCM. When NK cells were preincubated with anti-IFNAR2, the increase of IFN-γ in response to HVJ-E was abolished. Data points are the mean ± SE of triplicate wells. This experiment was repeated three times with similar results. SE < 5%. Results were statistically analyzed using the unpaired t test