Figure 5.
Treatment of 4T1 tumors with M protein mutant VSV and IL-12. (a) 4T1 cells were infected with rwt and rM51R-M viruses at multiplicities of 10 and 0.1PFU per cell. Cell viability was measured at different times post-infection. Data are expressed as the cell viability of mock-infected cells. (b) 4T1 cells were injected subcutaneously in the flanks of BALB/c mice. Animals with palpable tumors were randomly separated into five experimental groups (5–10 animals per group) and were injected in the tumor with 1 × 107 PFU of rM51R-M virus at days 1, 3 and 5, 50 μg of IL-12 plasmid at days 1 and 3, or PBS alone as a negative control (mock). Tumor volume was measured daily with calipers. Results are expressed as the change in tumor volume on treatment of mice with rM51R-M virus and/or IL-12. Data represent two separate experiments and are shown as the percentage of original tumor size on day 1 (mean ± s.e.). (c) Viral antigen staining in sections of 4T1 tumors from untreated mice or mice treated with rM51R-M virus and rM51R-M + IL-12.