Osteopontin regulates interleukin-17 production in hepatitis

► IL-17 and OPN levels were significantly increased in hepatitis (humans and mice). ► OPN markedly induced IL-17 expression by leukocytes (from humans and mice). ► β3 integrin was critically involved in the induction of IL-17 production by OPN. ► OPN-induced IL-17 expression was mediated through the p38, JNK, and NF-κB pathways.