FIG. 6.

LPS and IFN-γ primed PDL cells toward AFn-mediated nitric oxide production and exacerbated apoptosis. (A) Cells were treated with various combinations of LPS (20 μg/ml), IFN-γ (20 U/ml), and AFn or serum-free medium (M), and the level of nitric oxide generated was measured in the medium. CT, control; *, P value of <0.05 compared with results for AFn-treated cells under control conditions. (B) PDL cells were treated with different combinations of LPS (20 μg/ml), IFN-γ (20 U/ml), and AFn or serum-free medium (M) for 1 h or overnight (N), and the level of expression of iNOS was determined in the cell lysates of the treated cells by Western blot analysis. (C) The cell lysates from the experiment described for panel A were used to determine the level of apoptosis in cells treated with LPS, IFN-γ, and AFn in different combinations. The absorbance of the serum-free medium (M)-treated control cell lysates at 495 nm was arbitrarily defined as 1 unit, and the levels of absorbance of other cell lysates were expressed as the levels of change with respect to the result for the control cell lysate (CT). *, P value of <0.05 compared with result for AFn-treated cells under control conditions.