Figure 5

The inhibitory effect of specific siRNA on viral infection could be rescued by heat shock treatment. MARC-145 cells were transfected with no siRNA (Ctrl), scramble siRNA (Scr), or different concentrations of siRNAs targetting HSP70 (siHSP70). After 24 hours, cells were submitted to heat shock treatment (+HS) or not (-HS). 8 hours later, cells were mock infected or infected with PRRSV at an MOI of 0.1 and harvested at 24 h.p.i. (A) Cell extracts were analyzed by Western blotting. The levels of HSP70 and viral N protein were quantified by measuring band intensities and normalized with respect to the amount of β-actin. (B) The culture supernatants were collected and viral titers were determined by calculating by CCID₅₀. Data are mean ± SD, n = 3. *p < 0.05, **p < 0.01.