Specificity of suppression of tumor growth after treatment with intratumoral administration of AdmCD40L-transduced DCs compared with AdmCD40L-modified fibroblasts.
(A) Tumor growth. Groups of Balb/c mice were challenged subcutaneously with 2 × 105 CT26 cells (day 0). On day 7, bone marrow DCs (□) or syngenic fibroblast CL7 cells (○) were transduced in vitro with AdmCD40L at moi of 40 for 24 hours. Mice bearing day 8 established tumors were given 2 × 106 modified cells intratumorally. Controls included tumor-bearing mice without any treatment (Δ). The size of each tumor was assessed 3 times per week, and is reported as the average tumor area (mm2) ± standard error (n = 5 per group). Asterisks indicate significant differences at 95% confidence limits between AdmCD40L-transduced DCs and all other groups. (B) Tumor-specific cytotoxic T lymphocyte activity. Ten days after treatment described for panel A, the splenocytes were isolated, restimulated, and assayed as in Figure 4A,B. Shown are data for 51Cr-labeled CT26 targets. Results are presented as the mean ± standard error (n = 3/data point). In all groups, lysis of control 51Cr-labeled SVBalb targets was within 8% (not shown).
