Quantification of cytokines of BMDCs by qRT-PCR. BMDCs were incubated with either rHuN4-GM-CSF or the parental virus at MOI of 0.3 at 24, 48, 72 and 96 hpi. LPS was used as a positive control, and the medium from untreated cells (Mock) served as a negative control. Total RNA was prepared and used in a qRT-PCR to determine levels of mRNA levels for cytokines. (A) GM-CSF; (B) IL-12; (C) IL-1β; (D) IFN-γ; (E) IL-4; (F) IFN-γ. The horizontal lines represent the geometric mean for each group, and statistical analysis was performed. *: P < 0.05; **: P < 0.01.