Figure 7. Localized vPD1 therapy can treat metastatic melanoma.

(A–C) C57/B6 mice were injected with B16/F10 cells both SQ (4x10⁵ cells) and IV (1x10⁵ cells). On day five, animals were given either mock injection or IP injection of depleting antibodies against CD4 and either CD8 or NK1.1. Animals were then separated further and given IT injection of either saline or 1x10⁷ FFU of vPD1 into the SQ lesion on days 7, 9, and 11. This resulted in six cohorts: saline (n=7), saline + αCD4 (n=5), vPD1 (n=8), vPD1 + αCD4 (n=10), vPD1 + αCD4 + αCD8 (n=8), vPD1 + αCD4 + αNK1.1 (n=8). Antibody depletion was repeated on day 12. On day 16, mice were euthanized and the lungs examined for the presence of melanin⁺ lesions. (A) Pictures of representative lungs from the indicated cohorts. (B) Average number of melanin⁺ lesions (regardless of size) present in the lungs of each mouse. (C) Average size of each melanin⁺ lesion (regardless of number) present in the lungs of each mouse. Data represents summation of two independent experiments. Significance was determined using unpaired students T-Test (* = p<0.05 and *** =p<0.001). (D and E). C57/B6 mice were injected with B16/F10 cells both SQ (4x10⁵ cells) and IV (1x10⁵ cells). On day five, animals were given either mock injection or IP injection of a depleting antibody against CD4. Each group was then separated into two cohorts and given IT injection of either saline or 1x10⁷ FFU of vPD1 into the SQ lesion on days 7, 9, and 11. Animals were then monitored daily for body weight and euthanized when they displayed either a body weight <80% of starting weight or a BCS=2.0. (D) Average animal body weight for each group as a percentage of starting weight. (E) Overall survival of animals in each cohort. Data represents summation of two independent experiments. Significance was determined using log-rank test.