H5N1 NS1 reduces surface IFNAR1 but not IFNAR2 expression.

<p><b>A</b>) HeLa cells were transfected with either GFP vector alone (green) or GFP vector containing HA-tagged NS1 (red), then 24 hr post-transfection, GFP-positive cells were FACS sorted and stained for IFNAR1 or IFNAR2 and analyzed by FACS. Data are representative of three independent experiments. <b>B</b>) HeLa cells were transfected with HA-tagged NS1 plasmid and 24 hr post-transfection were fixed and stained for HA (green) and either IFNAR1 (red; upper panel) or IFNAR2 (red; lower panel), and analyzed by confocal microscopy. Data are representative of two independent experiments. <b>C</b>) HeLa cells were transfected with either GFP vector alone () or GFP vector containing HA-tagged NS1 (▪). 24 hr post-transfection, GFP positive cells were FACS sorted, RNA extracted and cDNA synthesized. <i>Ifnar1</i>, <i>ifnar2</i> and <i>β</i>-actin gene expression were analyzed by RT-PCR. Gene expression was calculated relative to β-actin gene expression and normalized to cells transfected with GFP vector alone. Data are representative of two independent experiments. Significant differences (asterisk) were determined by Student's t-test (p<0.05).