RO 90–7501 enhances the expression of endogenous IFN-β gene in both 293TLR3HA and human macrophage cell line THP-1.

<p>(A) 293TLR3HA cells were mock treated or treated with 10 µM of RO 90–7501, 2 µg/ml poly I:C, alone or in combination. The cells were harvested at the indicated time since start of the treatment. The levels of IFN-β and β-actin mRNAs were determined by semi-quantitative RT-PCR. (B) THP-1 cells were mock treated or treated with the indicated concentrations of poly I:C in the absence or presence of 10 µM RO 90–7501 for 6 h. The levels of secreted type I IFN were then determined with HEK-Blue IFN-α/β cells using culture media transferred from treated THP-1 cells. The level of ISG54 promoter driven SEAP expression in the supernatant was then determined with QUANTI-Blue and expressed as absorbance values at 655 nm, normalized to mock treated controls (mean +/− standard derivations, n = 8). P values were calculated using the two-tailed student t test. (C) 293TLR3HA cells were mock treated or treated with the indicated concentrations of poly I:C in the absence or presence of 10 µM RO 90–7501 for 6 h. Secreted IL-8 in culture media from treated 293TLR3HA cells were determined with a human IL-8 ELISA kit, and expressed as absorbance values at 450 nm (mean +/− standard derivations, n = 3).