Fig. 6: IL1R1 ablation or inhibition in vivo reduces tumor growth and regulates immune cells in the TME.

a Generation of ColVI^cre+IL1R1^fl/fl mice. b Experimental design of both in vivo assays. Upper diagram: MC38 cells were injected into both flanks of ColVI^cre+IL1R1^fl/fl mice and ColVI^cre-IL1R1^fl/fl control littermates and tumor growth was measured over time. Lower diagram: CT26 cells were injected into both flanks of BALB/c mice. Mice were treated with Anakinra (10 mg/kg) on days 3, 7, 11, 15 and 23 after tumor cell implantation and tumor growth followed over time. c IL1R1 expression in colon fibroblasts from ColVI^cre+IL1R1^fl/fl and ColVI^cre-IL1R1^fl/fl mice as measured by FACS, n = 3 mice per condition. d–f. Tumor volumes (cm³) measured over time and shown as mean ± SEM from one representative experiment (n = 4 mice in the ColVI^cre+IL1R1^fl/fl and n = 5 mice in the ColVI^cre-IL1R1^fl/fl condition, respectively) out of three independent experiments in d, tumor volumes at experimental endpoint pooled from three independent experiments and normalized to the control, with n = 11 mice per condition in e, Th17 cells (CD4⁺ RORγT⁺ IL-17⁺ cells, shown as % of live cells) in tumors as assessed by FACS in one representative experiment of three, with n = 4 mice per condition in f in ColVI^cre+IL1R1^fl/fl and ColVI^cre-IL1R1^fl/fl mice subcutaneously implanted with MC38 cells. g Th17 cell differentiation (CD4⁺ RORγT⁺ IL17⁺ cells, shown as % of live cells) upon co-culture with fibroblasts from ColVI^cre+IL1R1^fl/fl (KO) or ColVI^cre-IL1R1^fl/fl (WT) mice (n = 6 per condition), as assessed by FACS. h PD-L1 expression in tumors assessed by IF in one representative experiment of three, with n = 7 tumors per condition in ColVI^cre+IL1R1^fl/fl and ColVI^cre-IL1R1^fl/fl mice subcutaneously implanted with MC38 cells. i–k Tumor volumes (cm³) measured over time and shown as mean ± SEM with n = 8 mice treated with Anakinra or n = 7 mice treated with the vehicle control out of two independent experiments in i, tumor volumes at experimental endpoint pooled from two independent experiments in j, IL-17-producing cells (shown as % of live cells) isolated from tumors at experimental endpoint as assessed by flow cytometry in k in mice treated with Anakinra or the vehicle control. Two independent experiments are pooled in j-k to show a total of n = 7 mice treated with Anakinra or n = 6 mice treated with the vehicle control. Volumes of tumors from both flanks were averaged for each mouse in panels d, e, i and j. Th17 and IL-17⁺ cells from both flanks were averaged for each mouse in f and k. l Th17 scores in TCGA patients. Patients were split into IL1R1^hi (upper quartile) and IL1R1^lo (lower quartile), either in all CMS or in CMS4 only. Repeated measures ANOVA in d and h. Two-sided unpaired t-tests in e–g, i–l; ***p < 0.001. Red or black horizontal lines in e–h and j–k represent the median.