Fig. 2

AHR in macrophages influences breast cancer metastasis and Treg cell differentiation. a–c Wild-type (Control) and Ahr^flflLyz2^Cre+/− mice were inoculated with 4T1 cells in the mammary gland fat pad for 35 days. Tumor weight (n = 7 for each group) (a), the number of macroscopic metastases in the lungs (n = 7 for each group) (b), and picric acid-stained lungs (n = 3 for each group) (c) were assessed. d H&E staining of lung sections from Ahr^flflLyz2^Cre−/− (Control) and Ahr^flflLyz2^Cre+/− tumor-bearing mice(n ≥ 6). Scale bars, 400 µm. e Survival of 4T1 tumor-bearing wild-type (Control) and Ahr^flflLyz2^Cre+/− mice (n = 8 for each group). f Flow cytometry analysis on Treg cells in the lungs of Ahr^flflLyz2^Cre−/− (Control) and Ahr^flflLyz2^Cre+/− mice bearing tumor for 14 days (n = 3 for each group, repeated three times). g Flow cytometry analysis on the impact of AHR in macrophages on Treg cell differentiation. BMDMs from wild-type (Control) or Ahr^−/− mice were pretreated with normal medium (Control medium) or 4T1-CM for 2 days. Naïve CD4⁺ T cells were co-cultured with pretreated BMDMs for 3 days under the Treg differentiation conditions (n = 4 for each group, repeated four times). Data are analyzed by unpaired two-tailed t-test (a, b, f, g) or Mann Whitney test (d), or Log-rank (Mantel-Cox) test (e) and presented as mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, ns, no significance