Figure 3.

Depletion of CD8⁺ T cells abrogates the therapeutic effect of anti‐OX40 monoclonal antibody (mAb) in combination with radiotherapy. The Lewis lung carcinoma‐ovalbumin‐bearing mice were treated with anti‐OX40 mAb in combination with radiotherapy in CD4⁺‐, CD8⁺‐, or natural killer (NK) cell‐depleted mice. (a) Antitumor activities and (b) survival induced by treatment with or without antibody depletion are shown. αCD8 denotes depletion by anti‐CD8 mAb. The bars indicate the mean ± SE of six mice in each experimental group. *P = 0.092 versus the RT + IgG group. Similar results were obtained in three separate experiments. PBS, phosphate‐buffered saline; RT, radiotherapy.