Therapeutic efficacy of combination therapy based on the dendritic cells (DC) maturation, treatment schedule, and tumor size. (a) Tumor-bearing mice were treated with Ad-ΔB7/IL12/GMCSF in combination with mature or immature DCs. Similar antitumor effects were observed in combination therapies using mature or immature DCs. (b,c) Effect of the treatment schedule of oncolytic adenovirus and DCs on antitumor efficacy. Tumors were treated with Ad-ΔB7/IL12/GMCSF prior to DC vaccination (filled triangles), Ad-ΔB7/IL12/GMCSF and DCs on alternating days (open diamonds), or Ad-ΔB7/IL12/GMCSF after DC vaccination (filled squares). Tumor treatment with Ad-ΔB7/IL12/GMCSF prior to DC vaccination induced the most potent antitumor efficacy. (d,e) Antitumor effect of combination therapies on large tumors. High-dose combination therapy induced potent antitumor effect on large tumors. Data points represent the mean ± SE. All results in this figure represent results of at least six mice per group. *P < 0.05; **P < 0.01. GM-CSF, granulocyte-macrophage colony-stimulating factor; IL, interleukin.