Fig. 6: Murine keratinocytes express only low levels of proIL-1β

a Numbers of keratinocytes (CD45⁻ CD49f⁺) and b fibroblasts (CD45⁻ CD140a⁺) expressing proIL-1α or proIL-1β in back skin of UVB-irradiated and non-irradiated wild-type mice as determined by flow cytometric analysis. The cell count of CD49f⁺ and CD140a⁺ cells per 300 mg of back skin tissue prior to and in response to UVB irradiation was quantified. Error bars represent mean ± SD of a representative experiment with n = 5 (8 h UV) and n = 10 (24 h UVB) animals/group. Two-way ANOVA with Tukey’s multiple comparison was performed, comparing non-irradiated and irradiated skin at two time points within each group (****p < 0.0001, ***p < 0.001). c, d The contribution of different cell types to the total number of proIL-1β-producing cells is indicated. Cell populations were defined as follows: CD45⁺ CD3^hi (DETCs), CD45⁺ CD3⁺ (T cells), CD45⁺ CD11b⁺ Ly-6G⁺ (neutrophils), CD45⁺ CD11b⁺ CD64⁺ Ly-6C⁺ (inflammatory macrophages), CD45⁺ CD11b⁺ CD64^lo Ly-6C⁺ (inflammatory monocytes), CD45⁺ CD11b⁺ CD64⁻ CD11c⁺ (DCs), CD45⁺ CD11b⁺ CD64⁻ CD11c⁻ (unknown cell type), CD45⁻ CD49f⁺ (keratinocytes) and CD140a⁺ (fibroblasts). c Wild-type mice were shaved and back skin was analysed for expression of proIL-1β in the above-mentioned cell types. d Wild-type mice were shaved and irradiated with UVB (300 mJ/cm²). Back skin of mice was harvested after 24 h and the different cell types were examined for proIL-1β expression using multicolour flow cytometry analysis. Error bars represent mean ± SD of a representative experiment with n = 10 animals per group. IL interleukin, DCs dendritic cells