Figure 5.

IL-17A induces IL-19 and IL-24 expression in human skin resident cells such as fibroblasts and keratinocytes, and IL-17A blockade reduces their expression. (A) IL-19 and IL-24 mRNA expression in fibroblasts of healthy donors (n=6) and psoriasis patients (n=4) without stimulation or stimulated with IL-1β, TNFα, IL-17A and IL-17F for 24 hours. (B) Healthy control skin fibroblasts and psoriatic fibroblasts (n=6 each) were co-cultured with unstimulated or anti-CD3/anti-CD28 stimulated memory CD4+ T cells from healthy controls for 72 hours. IL-19 and IL-24 mRNA expression in these co-cultures without treatment or treated with an anti-IL-17A antibody, anti-TNF antibody, their combination or an isotype control antibody. (C) Levels of human IL-19 and IL-8 protein in the supernatant of the above mentioned co-cultures without treatment or treated with an anti-IL-17A antibody, anti-TNF antibody, their combination or an isotype control antibody. Data are shown as means ± SEMs. *P < 0.05, **P < 0.01, and ***P < 0.001.