FIG 7.

HDAC1 is involved in the expression of viperin in IAV-infected cells. (A and B) The knockdown of HDAC1 expression decreased viperin expression in infected cells. A549 cells (2 × 10⁵) were transfected with nontargeting control (CT) siRNA or HDAC1-targeting (HD1) siRNA for 72 h. The cells were then infected with PR8 at an MOI of 0.5 for 24 h. (A) Total cell lysates were prepared, and HDAC1, viperin, PDI, and NP were detected in uninfected (UNI) and infected (INF) cell lysates by WB. (B) The viperin and PDI protein bands were quantified as Fig. 1C, and the amount of viperin was normalized to PDI. The normalized amount of viperin in CT siRNA-transfected INF cells was considered 100% for comparisons to HD1 siRNA-transfected INF cells. The data presented are means ± the standard errors of the means of three independent experiments; the P value was calculated using a t test. (C and D) The overexpression of HDAC1 increased viperin expression in infected cells. A549 cells (8 × 10⁵) were transfected with empty plasmid pcDNA3 or pcDNA3 containing HDAC1 for 48 h. The cells were then infected with PR8 at an MOI of 0.5 for 24 h. (C) Total cell lysates were prepared, and HDAC1, viperin, PDI, and NP were detected in uninfected (UNI) and infected (INF) cell lysates by WB. Lanes 1 to 3 were combined with lanes 4 and 5 of the same blot to remove an unwanted lane from the middle. (D) The percent change in viperin level was calculated as described above. The data presented are means ± the standard errors of the means of three independent experiments; the P value was calculated using a t test. MW, molecular weight.