FIG. 6.

Effects of anti-FasL and anti-hTNF-α on caspase-3 activity and apoptosis induced by A. actinomycetemcomitans LPS and CHX. TPA-differentiated U937 cells (10⁷ cells [A] or 10⁵ cells [B]) were pretreated for 1 h with anti-FasL (10 μg/ml), anti-hTNF-α (5 μg/ml), or nothing and were subsequently cotreated with A. actinomycetemcomitans LPS (1 μg/ml) and CHX (10 μg/ml) for 3 h. Following each treatment, caspase-3 activity (A) was determined using colorimetric assay kits and apoptosis (B) by morphological assessment using Hoechst 33258 dye, as described in Materials and Methods. Values shown (units per milligram of protein [A] or percent apoptotic cells [B]) are the means + SD (error bars) of three separate experiments, each conducted in triplicate.