Figure 6.

Arming VVΔTKΔN1L with interleukin (IL)-12 improves efficacy as a monotherapeutic agent. (A)–(E) DT6606 tumors were established in the flanks of immune-competent C57/Bl6 mice (n=6–7/group). Once palpable, mice were injected intratumoral with 1×10⁸ PFU VVΔTKΔN1L, VVΔTKΔN1L-mIL12 or PBS daily for 5 days. (A) Tumor growth was monitored and significance at each time point analyzed using two-way analysis of variance (ANOVA) with post hoc Tukey tests. Significance at day 34 is shown. (B) Kaplan-Meier survival analysis with log rank (Mantel-Cox) tests was used to assess survival. (C) DT6606 flank tumors were treated as above (n=3–4/group) and 14 days after the first treatment splenocytes were analyzed for response to growth-arrested Lewis lung carcinoma (LLC) or DT6606 (control) tumor cells ex vivo using interferon γ (IFNγ) ELISA after 72 hours coculture. (D) DT6606 tumors were treated as above and 14 days after the first treatment, tumor sections were immunostained with CD4 or CD8 antibodies (n=3–4/group). Representative images are shown (magnification x200) and a manual cell count pre-HPF (taken from 15 HPFs) depicted graphically. One-way ANOVA with post hoc Tukey tests was used to assess significance. (E) DT6606 tumors were treated as above (n=3–4/group) and 14 days after the first treatment, splenocytes analyzed using FACS for activated CD8+ T cells using CD44 and CD62L (of live, CD45+, CD3+, CD8+ populations). One-way ANOVA with post hoc Tukey tests were used to assess significance. In all cases, the mean±SEM is shown. *p<0.05; **p<0.01; ***p<0.001.