Role of uteroglobin-binding protein in antiflammin-1 promoting IL-10 expression and secretion in RAW264.7 cells induced by endotoxin

The present study investigated the effect of antiflammin-1 (AF-1) on LPS-induced IL-10 secretion from RAW264.7 cells through uteroglobin-binding protein (UGBP). Cultured RAW264.7 cells, a murine monocyte-macrophage cell line, were divided as following: control group, LPS group (1 μg/mL LPS), AF-1 group (100 μmol/LAF-1), LPS+AF-1 group (2 h of 100 μmol/LAF-1 pretreatment before LPS addition), and LPS+AF-1+anti-UGBP group (30 min of anti-UGBP antibody pretreatment before successive treatments with AF-1 and LPS). IL-10 concentration in the supernatants was detected by ELISA assay, and the level of IL-10 mRNA expression in macrophage was detected by using RT-PCR method. The results showed that AF-1 significantly increased LPS-induced IL-10 secretion in RAW264.7 cells in a dose dependent way, and up-regulated its mRNA level. Anti-UGBP antibody pretreatment attenuated the augmented effect of AF-1 on LPS-induced IL-10 secretion and gene expression. These results suggest that AF-1 promotes LPS-induced IL-10 secretion from macrophages, and this effect is mediated by UGBP.