Figure 3.

Effect of anti-CD80 antibodies on allogeneic PBL proliferation in response to CD80-expressing HeLa cell clones in the absence and presence of exogenous IL-2. The uptake of ³H-thymidine by PBL was measured after 5 days of coculture with HeLa vector control clone or HeLa clones expressing CD80 in the absence (a) or presence (b) of exogenous IL-2. No antibody (open bars), isotype control antibody (grey bars) or anti-CD80 antibody (closed bars) were added at 1 µg/ml at initiation of the assays and ³H-thymidine was added at 0·5 µCi/well for the final 18 hr of coculture. Data are representative of two independent experiments. Error bars represent the standard deviation of ³H-thymidine incorporation in triplicate cultures.