Fig. 6. Mono-7D6-Fab promotes therapeutic antitumor T cell responses against pre-established melanoma lung metastases.

(A and B) B6 mice were intravenously injected with B16-F10 melanoma cells. Three days later, OT-I or Pmel-1 CTLs were adoptively transferred into tumor-bearing recipients. Subsequently, mice were injected with either control Ms IgG Fab or Mono-7D6-Fab. In addition, all mice were treated with 120,000 U of human IL-2 on day 3, followed by 60,000 U of human IL-2 on each of days 4 and 5. Mice were sacrificed after 28 days. (A) Lung photographs from one independent experiment. (B) Quantification of melanoma found in lungs. Dots represent individual mice with data pooled from two independent experiments (mean ± SEM; *P < 0.05, ***P < 0.0005, two-tailed unpaired Student’s t test). (C and D) Total CD8⁺ T cell counts positive for staining with K^d/hgp100 dextramer found in pooled (C) mediastinal lymph nodes or (D) lungs of mice adoptively transferred with Pmel-1 CTLs from (A) and (B) (mean ± SEM from triplicate samples; **P < 0.005, ***P < 0.0005, two-tailed unpaired Student’s t test). (E) Three days after B16-F10 injection, Pmel-1 CTLs were adoptively transferred into B6 recipients, together with Ms IgG Fab or Mono-7D6-Fab treatment [as described in (A) and (B)]. Survival was monitored (n = 10, **P < 0.005, Mantel-Cox log-rank test). (F and G) B6 mice were intravenously injected with B16-F10 melanoma cells. Three days later, mice were intraperitoneally injected with anti–CTLA-4 and anti-PD1, or control antibodies. In addition, on day 3, mice were intravenously injected with either Mono-7D6-Fab or control Ms IgG Fab. Subsequently, on days 5, 7, and 9, mice were re-treated with anti–CTLA-4 and anti-PD1 (or control) antibodies. After 24 days, the lungs were collected. (F) Lung photographs from one independent experiment. (G) Quantification of melanoma found in lungs. Dots represent individual mice (mean ± SEM; *P < 0.05, **P < 0.005, ***P < 0.0005, two-tailed unpaired Student’s t test).