Figure 1.

Transfer of tumor-specific CD4⁺ T cells potently restricts lung metastasis from melanoma. 0.5 × 10⁶ B16-GP cells were injected intravenously into C57BL/6J mice (CD45.2⁺) through tail vein to develop the lung metastasis. On Day 7, tumor-bearing mice were administered with CTX (200mg/kg) intraperitoneally and transferred with 2 × 10⁶ CD45.1⁺activated tumor-specific CD4⁺ T cells or PBS (control) intravenously 12 hours later (Day 8). (A, B) Image of lung samples harvested from metastasis model in which C57BL/6J mice (n=6/group) were treated with PBS or 2 × 10⁶ SMARTA cells in total (once or in three divided doses for 3 consecutive days) and sacrificed seven days post-transfer (A), with the numbers of metastatic foci calculated (B). (C, D) Image of lung samples harvested from the lung metastasis model in which the C57BL/6J mice (n=5/group) with established B16-GP lung metastasis were treated with PBS, activated SMARTA or OT-II cells, and B16-GP bearing Cd8 ^-/- mice (n=5/group) were treated with either activated SMARTA cells or PBS (C). Mice were sacrificed on Day 18 post transfer. The statistical analysis of the numbers of metastatic foci in the lung tissues (D). (E) Survival curve of tumor-bearing mice (n=10/group) treated with activated SMARTA cells or control PBS. Statistical differences are calculated by one-way ANOVA (B, D, number of metastasis) and Log-rank test (E, survival curve). ns, not significant, *p < 0.05, ***p < 0.001, ****p < 0.0001. Data are presented as mean ± SEM.