Interleukin-10 inhibits tumor necrosis factor-α production in lipopolysaccharide-stimulated RAW 264.7 cells through reduced MyD88 expression

The mechanism of interleukin (IL)-10-mediated inhibition of tumor necrosis factor (TNF)-alpha production was studied by lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. IL-10 inhibited TNF-alpha production transiently at an early stage after LPS stimulation. IL-10 inhibited the activation of nuclear factor (NF)-kappaB, p38 and stress-activated protein kinase (SAPK) in LPS-stimulated RAW 264.7 cells. Although the level of MyD88 protein increased in response to LPS, IL-10 prevented the LPS-induced MyD88 augmentation. There was no significant difference in the MyD88 mRNA expression between the cells pretreated with or without IL-10 in response to LPS. Therefore, IL-10 was suggested to inhibit LPS-induced TNF-alpha production via reduced MyD88 expression.