The comparative infectivity, replication, reproduction, and cytolytic efficacy of the fiber-modified replication-competent recombinant adenoviruses in human glioma cell lines
(A and B) Comparative dose-dependent cytotoxicity. Cells (5 × 103/well) were infected in suspension with a serial 3-fold dilution of the indicated fiber-modified (A) and fiber-modified luciferase-expressing (B) rAds starting from 20,000 vp/cell (T98G cells), 6,666 vp/cell (LN18 and LN229), or 2,222 vp/cell (DBTRG) and analyzed 5 or 7 (T98G cells) days post-infection by resazurin/Alamar Blue cell viability assays. Replication-defective Ad5ΔE1A was used as a negative control. Normalized data are presented as the mean ± SD of at least two independent experiments in technical triplicates. (C) Comparative dose-dependent infectivity. Cells (2.5 × 104/well) were infected in suspension with a serial 3-fold dilution of the indicated luciferase-expressing rAds starting from 2,222 vp/cell or 741 vp/cell (LN229). Luminescence (relative light units [RLU]) was analyzed 24 h post-infection. Only ≥2-fold differences in the mean RLU values relative to Ad5-Δ24-RGD_E1B-p2A-Fluc are designated. The mean ± SD of two independent experiments in four technical replicates is shown. (D) Ad DNA copy number quantification by qPCR. Cells (5 × 105/well) were infected in suspension with 100 vp/cell and collected 24 and 48 h post-infection. Normalized data are shown as the mean ± SD of at least two independent experiments. PCR runs were conducted in four technical replicates. Only ≥1.5-fold differences in the mean DNA copy numbers relative to Ad5-Δ24-RGD are designated. (E) Total virus production (both culture cell extracts and supernatants including viral inoculum) was determined 24 and 48 h post-infection using anti-Ad staining. Cells (2.5 × 105/well) were infected in suspension at an MOI of 50 IFU/cell. The mean ± SD of two independent experiments is shown. Only ≥2-fold differences in the mean total virus production values (IFU/mL) relative to Ad5-Δ24-RGD are designated. See also Figure S4.