Molecular cloning of chicken interleukin-17B, which induces proinflammatory cytokines through activation of the NF-κB signaling pathway

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Interleukin (IL)-17B is a little known member of the IL-17 cytokine family, which plays an important role in immunity by regulating the expression of proinflammatory cytokines. In this study, we determined the coding sequence and biological functions of a novel chicken IL-17B (chIL-17B). The full-length chIL-17B coding sequence includes 567 nucleotides encoding 188 amino acids, which was identified in small intestinal epithelial cells. The chIL-17B protein shares 96.48% amino acid sequence identity with turkey, 92.57% with duck, and 44.92–64.06% with mammalian IL-17B proteins. ChIL-17B shares three exons and two introns with mammals, turkey, and duck. Moreover, IL-17B mRNA was more highly expressed than IL-17A mRNA in several organs of chickens infected with <I>Salmonella</I> and was upregulated in chicken cell lines following LPS stimulation. In addition, in chicken cell lines, chIL-17B induced the mRNA expression of several proinflammatory cytokines, including IL-1β, IL-6, LITAF, and INF-γ, but not IL-17A, and activated MyD88, TAK1, NF-κB1, and SOCS1, which are associated with the NF-κB signaling pathway. Taken together, chicken interleukin-17B plays a critical role in host defense against the bacterial pathogens, and regulates proinflammatory cytokines by activating the NF-κB signaling pathway.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel chicken interleukin-17B (chIL-17B) was cloned. </LI> <LI> Chicken IL-17B expression was upregulated in response to bacterial infection. </LI> <LI> Chicken IL-17B functions through the NF-κB signaling pathway. </LI> <LI> ChIL-17B overexpression activates proinflammatory cytokines in HD11, OU2, and CU91 cells. </LI> </UL> </P>