Fig. 5

CAF-derived IL-1β facilitates lung metastasis. a Scheme of experiments analysed in b–e. shIl1b 4T1 mammary carcinoma cells were orthotopically co-injected with WT NMFs (Il1b^+/+) or with Il1b^−/− NMFs into the right inguinal mammary glands of Il1b^−/− female mice. b Growth curves of 4T1 tumours injected with WT NMFs (Il1b^+/+) or with Il1b^−/− NMFs. n = 10 mice per group. c Tumour weight at termination of experiment. n = 10 mice per group. d Representative H&E staining of lung sections from injected mice. Insets depict spontaneous metastases (arrows). e Quantification of metastatic lesions per lung (serial sections of whole lungs were analysed). n = 9 and 10 individual mice per group (WT and Il1b^−/−, respectively). Data are representative of three independent experiments. f–h BALB/c female mice were orthotopically injected with shIl1b 4T1 cancer cells admixed with WT NMFs (Il1b^+/+) or with Il1b^−/− NMFs. f Micro-CT intravital imaging of lungs shows spontaneous macrometastases (arrows). g H&E staining of lung tissue sections showing metastatic nodules. Insets depict enlarged fields of spontaneous metastases. h Quantification of metastatic load performed by analysing the area of metastatic foci per section of serially sectioned lungs. n = 6 individual mice per group. Representative of two independent experiments. i–l Flow cytometry analysis of MDSC infiltration into primary tumours (n = 5 or 6 individual tumours per group, WT and l1b^−/−, respectively) i, j, or lungs (n = 6 per group) k, l of 4T1-tumour bearing mice. Data presented are percentage of CD45⁺ CD11b⁺ cells, normalised to WT. Representative of three independent expirements. In b, c, e, h, i, j, k, l data are presented as mean ± s.e.m; Welch’s t-test. Source data are provided as a Source Data file