FIGURE 1.

Inhibition of TNF-α–induced NF-κB activation by HSV-1 UL2. (A) HEK293T cells were transfected with promoter reporter plasmids NF-κB–Luc and pRL-TK, together with 500 ng of Flag empty vector or pUL2-Flag plasmid. Twenty-four hours posttransfection, cells were treated with or without 10 ng/mL of the recombinant human TNF-α and incubated for an additional 6 h, followed by cell lysed. Nuclear factor κB–driven luciferase activity was detected by DLR, as described in section “Materials and Methods.” (B) was carried out as (A); except that for an increase indicated amounts (100, 250, and 500 ng) of UL2-Flag expression plasmid were used. Cell lysates were divided into two aliquots; one aliquot was used for DLR detection, and the other was used for WB analysis to detect the protein expression of transfected plasmid. The expression of UL2 was analyzed by WB with anti-Flag mAb, and β-actin was used to verify equal loading of protein in each lane. Dual-luciferase reporter data were normalized for transfection efficiency through measuring firefly luciferase activity and Renilla luciferase activity, and values were shown as the ratio between the firefly and Renilla luciferase. Data were expressed as means ± SD from three independent experiments. ***P < 0.001.