Fig 1.
Expression of PD-L1/PD-1 in an M05 melanoma model.
(A) Expression of PD-L1 on M05 tumor cells after (left) no treatment or (right) IL PV-10 injection as measured by flow cytometry. Gray histogram: isotype control. (B) Expression of PD-1 on total CD3+ and CD3+CD8+ tumor infiltrating lymphocytes (TIL) isolated from untreated or IL PV-10 treated M05 tumors.
Fig 2.
Combination therapy with IL PV-10 and anti-PD-1 results in delayed tumor growth.
Mice received 3x105 M05 tumor cells SC on a single flank on Day 0. On Day 7, mice received either 50 μl PV-10 or PBS IL, and mice received anti-PD-1 antibody IP twice per week beginning on Day 8. Tumors were measured until the endpoint was reached.
Fig 3.
Increased M05-specific T cell activity after IL PV-10 injection and PD-1 blockade.
Mice received 3x105 M05 tumor cells SC on a single flank on Day 0. On Day 7, mice received 50 μl PV-10 or PBS IL, and mice received anti-PD-1 antibody IP twice per week beginning on Day 8. Spleens were harvested on Day 21–24. (A) Splenocytes were co-cultured with M05 cells for 48 hours and supernatants were collected. IFN-gamma was measured by ELISA. (B) CD8+ and OVA-tetramer positive T cells were measured by flow cytometry.
Fig 4.
Effect of combination therapy with IL PV-10 and PD-1 blockade is mediated by CD8+ T cells.
Mice received 3x105 M05 tumor cells SC on a single flank on Day 0, and were given 300 μg IP NrIgG control antibodies, 2.43 antibody to deplete CD8+ T cells, GK1.5 antibody to deplete CD4+ T cells, or PC61 antibody to deplete CD25+ Tregs. Antibodies were given twice per week until the completion of the experiment. On Day 7, mice received 50 μl PV-10 or PBS IL, and mice received anti-PD-1 antibody IP twice per week beginning on Day 8.
Fig 5.
IL therapy with PV-10 in combination with anti-PD-1 antibodies leads to delayed growth of bystander M05 tumors.
Mice received 3x105 M05 tumor cells SC on bilateral flanks on Day 0. On Day 7, right flank tumors were injected with 50 μl PV-10 or PBS IL. Mice received 300 μg anti-PD-1 and NrIgG antibodies beginning on Day 8 and continuing 2x/week until mice had reached endpoint. Tumor growth was measured in (left panel) tumors treated with IL PBS or PV-10 and (right panel) untreated, bystander tumors. Each line represents the growth of tumor in a single mouse (n = 5–6 mice per treatment group).
Fig 6.
IL therapy with PV-10 in combination with anti-PD-L1 antibodies leads to delayed growth of treated and bystander B16 tumors.
Mice received 1x105 B16 tumor cells SC on bilateral flanks on Day 0. On Day 7, right flank tumors were injected with 50 μl PV-10 or PBS IL. Mice received 300 μg anti-PD-L1 or NrIgG antibodies beginning on Day 8 and continuing 2x/week until mice had reached endpoint. Combination of PV-10 and anti-PD-L1 led to a delayed tumor growth in A) B16 tumors treated with IL PV-10 and B) untreated B16 bystander tumors.
Fig 7.
Increased T cell infiltration into Bystander M05 Tumor after IL PV-10 injection and anti-PD-L1 antibody treatment.
Mice received 3x105 M05 tumor cells SC on a both flanks on Day 0. On Day 7, mice received 50 μl PV-10 or PBS IL, and mice received anti-PD-L1 or IgG antibody IP twice per week beginning on Day 8. Mice were euthanized on Day 21, tumors were harvested and TILs were isolated from tumors. Infiltrating (A) CD4+ and (B) CD8+ T cells were measured by flow cytometry.