Overexpression of STAT2 and IFNAR2 is sufficient to recapitulate differentiation-dependent changes in neuronal type I IFN-stimulated gene expression.

<p>(A) Type I IFN dose-response curves were analyzed in undifferentiated BE(2)-C (closed circles), differentiated BE(2)-C/m (closed squares), and undifferentiated cells transfected with either empty vector (open circles, solid line) or IRF-9-, IFNAR2-, and STAT2-overexpression vectors (open circles, dashed line). Normalized SEAP responses 24 h after stimulation with IFNα-A/D were fit using a variable slope nonlinear regression to calculate EC₅₀ and Hill slope values. (B) BE(2)-C cells were transfected with the indicated expression plasmid combinations, and EC₅₀ and Hill slope values were calculated from independently fit type I IFN dose-response curves as noted above in (A). *<i>p</i><0.05, **<i>p</i><0.005, relative to vector control. Upper and lower dashed reference lines indicate calculated response values for untransfected undifferentiated and differentiated cells, respectively. Representative immunoblots from one of four independent experiments indicate equivalent overexpression of IRF-9, IFNAR2, and STAT2 in the appropriate samples. A GFP-overexpression plasmid was co-transfected as a control for transfection efficiency, and GAPDH was analyzed as a loading control.