Inhibition of protein kinase R (PKR) activity attenuated HBx-siRNA-induced innate immune responses.

Abstract

<p>(A) HepG2.2.15 cells were treated with or without PKR inhibitor C16, and then transfection experiments were performed for 24 h. Levels of IFN-α and IFN-β mRNA were analyzed by real-time PCR and presented relative to mock transfection (left). The levels of IFN-α in supernatants were examined by ELISA (right). (B) The experiment was performed as <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0027931#pone-0027931-g004" target="_blank">Fig. 4A</a>. Levels of IFN-stimulated gene (ISG)15 and ISG56 mRNA were analyzed by real-time PCR and presented relative to mock transfection. (C) p-Stat1 expression was detected by flow cytometry when siRNA was transfected for 4 h. (D) The experiment was performed as <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0027931#pone-0027931-g004" target="_blank">Fig. 4A</a>, mRNA levels of TNF-α and IL-6 were analyzed by quantitative real-time PCR and were presented relative to mock transfection. (E) siPKR were transfected into cells, then PKR protein expression was assayed by Western Blot (top). siRNA4 and siRNA targeting PKR were cotransfected into HepG2.2.15 cells for 24 h, then mRNA levels of IFN-α and IFN-β were analyzed and presented relative to mock transfection (bottom). Data are expressed as the mean ± SD from at least three separate experiments. *<i>p</i><0.05 versus siRNA4-treated group.</p