Fig. 4.

Mast cells express several RLRs, and expression levels of these RLRs are upregulated by viral infection. mRNA levels of MDA5, RIG-I, PKR and TLR3 in unstimulated BMMCs (a) or BMMCs stimulated with VSV (MOIs = 3; b) for 8 h were quantified by real-time PCR and expressed as relative expression levels based on the MDA-5 level (MDA5 = 1). NS = No stimulation. c MDA5 and RIG-I expression at protein levels in unstimulated or VSV (MOIs = 3)-stimulated-BMMC for 24 h were analyzed by Western blotting. Equal loading of protein in each lane was confirmed by reprobing the same membrane with anti-β-actin. d mRNA levels of MDA5, RIG-I, PKR and TLR3 in BMMCs 8 h after stimulation with 10 µg/ml of poly A:U, poly I:C(H) and poly I:C(L) were quantified by real-time PCR and expressed as relative expression levels based on the expression levels of each of the receptors in unstimulated mast cells. Means ± SD of 3 experiments. * p < 0.05, ** p < 0.01, *** p < 0.001, vs. unstimulated cells.