Effect of anti–4-1BBL and anti-CD70 on the therapeutic activity of anti-CD40 in BCL1 cells. (A) Groups of mice (n = 5) received 1 × 107 BCL1 cells intravenously on day 0 and then anti-CD40 mAb on days 4, 5, 6, and 7 (250 μg/d). Where shown, mice also received anti–4-1BBL and/or anti-CD70 intraperitoneally on days 4, 7, 9, and 11 (500 μg/d). Mice were monitored for tumor development. Survival to the humane end point was plotted using the Kaplan-Meier method and analyzed for significance using the log-rank test. Control versus anti-CD40 treated, P < .002; control versus CD40 + anti–4-1BBL, P < .002; anti-CD40–treated versus anti-CD40 in the presence of anti–4-1BBL, P < .02. Representative result from 3 experiments. (B-C) Mice received 5 × 107 BCL1 cells intravenously on day 0 and then anti-CD40 mAb intravenously on day 4, and, where shown, anti–4-1BBL or anti-CD70 mAb intraperitoneally on days 4, 5, and 6 (500 μg/ day). Splenic tumor (idiotype+) and CD8 T cells were monitored by flow cytometry. (B) The total number of tumor cells (B) and the total number of CD8 cells (C) are shown. The arrows indicate the level of tumor and CD8 cells at the time of treatment. Data points are mean of 2 animals. The results represent 1 of 4 similar experiments.
