Figure 4.

Effects of anti-OX40 ligand (OX40L) monoclonal antibody (mAb) on CD4⁺ T-cell proliferation stimulated by allogeneic dendritic cells (DCs). (a) CD4⁺ T cells and allogeneic irradiated mature DCs (mDCs) were mixed and co-cultured in a 96-well culture plate for 5 days in the presence of the indicated reagents. Cells were pulsed with [³H]thymidine ([³H]TdR) (0·5 µCi/well) for the last 7 hr of culture and the incorporated radioactivity was measured in a liquid scintillation counter. Results are expressed as mean counts ± standard deviation (SD) of triplicate samples. The asterisk indicates a P-value of < 0·05 compared with the suppressed reactivity. (b) Effects of anti-OX40L mAb on the viability of DCs. DCs were cultured in RPMI-1640 supplemented with 10% fetal calf serum (FCS) in the presence of 100 µg/ml control mouse IgG2a (UPC-10; open circle) or anti-OX40L mAb (ik-5; closed square) and the viable cell number was counted by using Trypan-Blue dye exclusion.