Figure 8.
Ad5/35-Δ24_DBP-p2A-mOX40L treatment produces long-term survivors with immunological memory in an orthotopic syngeneic GL261 glioma model
(A) Dose-dependent mOX40L expression in human (n = 1) and murine glioma cells (n = 3 independent experiments) infected with Ad5/35-Δ24_DBP-p2A-mOX40L at the indicated MOIs and analyzed by flow cytometry 24 h post-infection. (B) Comparison of the plaque areas of the indicated rAds in A549 cells at day 8 post-infection. Data are presented as the mean ± SD; ns, nonsignificant difference by unpaired two-tailed t test with Welch’s correction. The sample sizes are indicated in the figure. (C) Kaplan-Meier survival curves of mice bearing GL261 tumors. rAds were intratumorally injected (1 × 108 IFU; 5 μL) on days 7, 9, and 11 after tumor cell implantation (n = 10, Ad5/35-Δ24; n = 9, Ad5/35-Δ24_DBP-p2A-mOX40L; n = 8, Ad storage buffer). Several long-term survivors (>100 days) in the rAd-treated groups are shown. Log rank test: Ad5/35-Δ24 versus Ad buffer, p = 0.8337; Ad5/35-Δ24_DBP-p2A-mOX40L versus Ad buffer, p = 0.3574). (D) GL261 rechallenge experiment with tumor cells implanted into the contralateral hemisphere of the long-term survivors (n = 2, Ad5/35-Δ24; n = 3, Ad5/35-Δ24_DBP-p2A-mOX40L) and naive mice (n = 10). Log rank test: Ad5/35-Δ24 versus Ad buffer, p = 0.2863; Ad5/35-Δ24_DBP-p2A-mOX40L versus Ad buffer, p = 0.0066).