As a critical adapter protein in Toll-like receptor (TLR)/Interleukin (IL)-1R signaling pathway, Myeloid differentiation protein 88 (MyD88) (plays an important role in immune responses and host defense against pathogens. This study was designed to provide a foundation and an important reagent for the mechanistic study of MyD88 and its role TLR/IL-1R signaling pathways in porcine immunity. Lentivirus-mediated RNAi was used to generate a porcine PK15 cell line with a silenced MyD88 gene and qPCR and Western blotting were used to detect changes in the expression of critical genes in the TLR4 signaling pathway. ELISA was used to measure the levels of seven proinflammatory cytokines-IL-1β, TNF-α, IL-6, IL-8, IL-12, MIP-1α, and MIP-1β-in cell culture supernatants after MyD88 silencing. We successfully obtained a PK15 cell line with 61% MyD88 mRNA transcript down-regulated. In PK15 cells with MyD88 silencing, the transcript levels of TLR4 and IL-1β were significantly reduced, while there were no significant changes in the expression levels of CD14 , IFN-α , or TNF-α . The ELISA results showed that the levels of most cytokines were not significantly changed apart from IL-8 without stimulation, which was significantly up-regulated. When cells were induced by LPS (0.1 μg/mL) for 6 h, the global level of seven proinflammatory cytokines up-regulated and the level of IL-1β, TNF-α, IL-6, IL-8 and IL-12 of Blank and NC group up-regulated more significantly than RNAi group ( P <0.05), which revealed that the MyD88 silencing could reduce the TLR4 signal transduction which inhibited the release of proinflammatory cytokines and finally leaded to immunosuppression.
- gene silencing
- TLR/IL-1R pathway
- proinflammatory cytokines
- ©2016 The Author(s)
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