Figure 4.

Increased potency of A2 vs. H3 (DR3) in inhibiting TL1A induced IFN-γ secretion and apoptosis in PBL and TF-1 cell line, respectively. (A) Inhibition of TL1A-induced secretion of IFN-γ in human PBL by increased concentration of A2 and H3. Cells were incubated for 72 h with 200 ng/ml TL1A, 20 ng/ml IL-12 and 50 ng/ml IL-18, and different concentrations of A2 and H3 inhibitors. The 1:10 diluted cell supernatant was analyzed by ELISA for detection of IFN-γ levels. The IFN-γ values were calculated according to IFN-γ calibration curve. (B) Inhibition of TL1A-induced apoptosis in TF-1 cells by increased concentration of A2 and H3. Cells were incubated for 6 h with 8 μg/ml of cyclohexamide (CHX) and 75 ng/ml of TL1A and the indicated concentration of A2 and H3 receptors. Following incubation, lysis buffer containing the caspase-3 fluorescent substrate DEVD-AMC was added and enzyme activity was monitored for 10 min. The data presented in the PBL and TF-1 experiments is the average of three independent repeats of each experiment and the error bars represent the standard deviation from the average.