Figure 4

Knocking-down TLR3 suppresses enhancement of c-IAP2 protein expression by poly(I:C). Western blot analysis of protein extracts from HeLa cells treated with poly(I:C) (500 ng/ml for 16 h) with or without pre-treatment with TLR3-specific and control (NS) siRNAs. The same membrane was stained successively with anti-c-IAP2, TLR3 and β-actin. Note that the control siRNA by itself enhanced TLR3 and c-IAP2 expression. This is consistent with previous observations and possibly related to the interaction of these small double-strand RNAs with the TLR3 itself regardless of their sequence [36]. In our transfection protocol siRNAs are at 100 nM for the first 4 h and 50 nM for the next 44 h. TLR3 inhibition was not complete with the siRNA n°1 which was apparently weaker than the siRNA n°2. However the siRNA n°1 was strong enough to prevent enhancement of TLR3 and c-IAP2 expression in the absence of poly(I:C). Data are representative of two similar experiments.