IFNγ-induced priming of ATP-stimulated ROS production by microglia.

(A-C) Examples of cells (upper images: brightfield images; lower images: DCFDA fluorescence images) kept unprimed (A) or primed with 10 ng/ml IFNγ (B) or 50 ng/ml IFNγ (C) for 24 h and maintained subsequently with or without 2 mM ATP for 1 h. Scale bars: 20 γm. (D) Mean DCFDA fluorescence intensities of cells maintained unprimed for 24 h and then either kept unstimulated (n = 1134) or stimulated with 2 mM ATP (n = 1137) for 1 h, of cells primed for 24 h with 10 ng/ml IFNγ and then not stimulated (n = 216) or stimulated with 2 mM ATP (n = 264) for 1 h, or cells primed for 24 h with 50 ng/ml IFNγ and subsequently kept unstimulated (n = 240) or stimulated with 2 mM ATP (n = 1089) for 1 h. Mean DCFDA fluorescence intensities of cells were normalized to the mean fluorescence intensity determined for unprimed and unstimulated control cells. ***, p<0.001.