Figure 6.

Tumor‐specific cytotoxic lymphocyte were generated by anti‐OX40 monoclonal antibody (mAb) in combination with radiotherapy. The Lewis lung carcinoma (LLC)‐ovalbumin (OVA)‐bearing mice were treated with the protocols as described in Materials and Methods. The lymphocytes in draining lymph nodes (DLN) were harvested from the treated mice. Harvested cells were used in (a) 8‐h and (b,c) 4‐h ⁵¹Cr‐release assays. Similar results were obtained in three separate experiments. Data are presented as the mean ± SE of triplicate samples. (a) Cytolytic activity by whole DLN cells from mice tested against LLC‐OVA. Cytolytic activity of (b) CD8⁺ and (c) CD4⁺ T cells in DLN from mice treated with anti‐OX40 mAb in combination with radiotherapy were tested against LLC‐OVA (closed circle), LLC (open circle), MBL‐2 (closed triangle), and YAC‐1 (open triangle). E : T indicates the effector : target ratio; RT, radiotherapy.