Fig. 6: IL-1R signaling in EGCs promotes SPP1⁺ TAM differentiation and tumor progression.

a–c Murine bone marrow-derived monocytes were cultured for 48 h with supernatant of primary embryonic neurosphere-derived EGCs, which were pre-incubated for 24 h with tumor microenvironment conditioned medium (TME-CM) or healthy-CM (H-CM) together with isotype IgG or anti-IL-1R (5 µg/mL each). Antibodies were removed from the CM through the application of Dynabeads™ Protein G prior to incubation with monocytes. Experimental design (a). Flow cytometry quantification of SPP1⁺ TAMs and C1Q⁺ TAMs after TME-EGCs (n = 7) (b) or H-EGCs (n = 4) (c) supernatant stimulation. d IL-6 concentration in the conditioned medium of H-EGCs and TME-EGCs pre-incubated with IgG or anti-IL-1R (n = 3 primary EGC cultures). e–g WT C57BL/6J mice were intracolonically (i.c.) injected with MC38 cells and embryonic neurosphere-derived WT EGCs or IL-1R1^−/− EGCs (1:1 ratio). Tumor growth and immune infiltration were assessed on day (d)14. Schematic representation of EGCs co-injection mouse model (e) with representative pictures (scale bar 2 mm) and quantitative comparison of tumor volume (n = 7 mice) (f). Data show absolute tumor-infiltrating TAM cell numbers per mg tumor tissue (n = 7 MC38 + WT EGCs, n = 6 MC38 + IL-1R1^−/− EGCs) (g). h–j GFAP^WtIL-1R1^fl/fl and GFAP^CreIL-1R1^fl/fl mice were i.c. injected with AKPT cells. Tumor growth and immune infiltration were assessed at d14. Schematic representation of orthotopic CRC mouse model (h) with representative pictures (scale bar 2 mm) and quantitative comparison of tumor volume (n = 12 GFAP^WtIL-1R1^fl/fl, n = 8 GFAP^CreIL-1R1^fl/fl) (i). Data show absolute tumor-infiltrating TAM cell numbers per mg tumor tissue (n = 11 GFAP^WtIL-1R1^fl/fl, n = 6 GFAP^CreIL-1R1^fl/fl) (j). Data are represented as mean ± SEM (d, f, g, i, j). Statistical analysis: paired two-tailed Wilcoxon test (b, c), two-way ANOVA test with correction for multiple comparisons (d) or unpaired two-tailed Mann-Whitney test (f, g, i, j). *p < 0.05, **p < 0.005, ***p < 0.0005, ****p < 0.00005, ns not significant. Source data and exact p values are provided as a Source Data file.