2. Figure Legend
Supplementary Fig. 1 IL-35 recombinant protein affects the production of IL-6 and CXCL8 in M5-stimulated HaCaT cells . HaCaT cells were seeded in 6-well plates and cultured for 12 h. After 12 h of culture, different concentrations of IL-35 (0, 50, 100, or 200 ng/mL) were added to the cells, which were further stimulated with M5 (10 ng/mL). The secretion of CXCL8 and IL-6 was detected by ELISA. (A) Expression of CXCL8 and (B) IL-6. *p < 0.05, **p < 0.01, ***p < 0.001. This experiment was repeated three times.
Supplementary Fig. 2. IL-35 recombinant protein alleviated pathological characteristics of psoriatic lesions in K14-VEGF-A-Tg mice. (A) Schedule of the therapeutic delivery of IL-35. (B) The phenotype of the mouse ear after therapy (n = 5). (C) Individual psoriasis area and severity index (PASI) scores of erythema, scaling, and thickness as well as cumulative PASI scores. (D) Hematoxylin and eosin (H&E) staining of the murine ear skin (original magnification × 200 and 400×, the 400× image is the enlarged image in the box in the 200× image). (E) Pathological score of ear sections using the Baker scoring system. Columns represent the mean, and bars represent the standard deviation (SD). ***p < 0.001. This experiment stands for an independent experiment.
Supplementary Fig. 3 Populations of myeloid-derived progenitor cells (MDSCs) were significantly increased in mice with imiquimod (IMQ)-induced psoriasis. (A) Experimental procedures and establishment of IMQ-induced psoriasis in mice. (B) Images of murine back-skin specimens. (C) Psoriasis area and severity index (PASI) score evaluation of erythema, scaling, and thickness, and cumulative scores for different groups in the mouse model of IMQ-induced psoriasis. (D) Detection of MDSCs in the spleen and skin tissues via flow cytometry and subsequent quantification analyses. **p < 0.01, ***p < 0.001.
Supplementary Fig. 4 Effect of IL-35 on the expansion of myeloid-derived progenitor cells (MDSCs) induced by granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-6 in vitro. (A-E) Bone marrow cells pre-treated with different concentrations of IL-35 (100, 200, and 400 ng/mL) or vehicle and were cultured with murine GM-CSF (40 ng/mL) and IL-6 (40 ng/mL). After four days, the numbers of CD11b+Gr-1+MDSCs (A, B), CD11b+Ly6G+Ly6Clowgranulocytic MDSCs (G-MDSCs) (C, D), and CD11b+Ly6G-Ly6ChighM-MDSCs (C, E) were analysed via fluorescence-activated cell sorting (FACS). Data are representative of three biological replicates, each using three technical replicates. ns, no significance.