Downregulation of common cytokine receptor gamma chain inhibits inflammatory responses in macrophages stimulated with Riemerella anatipestifer

Abstract

Th17-cell-mediated inflammation is affected by the soluble form of common cytokine receptor gamma chain (gamma(c)). We previously suggested that inflammatory cytokines including interleukin (IL)-17A are associated with Riemerella anatipestifer infection, which a harmful bacterial pathogen in ducks. Here, the expression profiles of membrane-associated gamma(c) (du gamma(c)-a) and soluble gamma(c) (du gamma(c)-b) in R. anatipestifer-stimulated splenic lymphocytes and macrophages, and in the spleens and livers of R. anatipestifer-infected ducks, were investigated. In vitro and in vivo results indicated that the expression levels of both forms of gamma(c) were increased, showing that marked increases were detected in the expression of the du gamma(c)-b form rather than the du gamma(c)-a form. Treatment with gamma(c)-specific siRNA downregulated mRNA expression of Th17-related cytokines, including IL -17A and IL-17F, in duck splenic macrophages stimulated with R. anatipestifer, whereas the expressions of interferon (IFN)-gamma and IL-2 were enhanced. The results showed that the upregulation of gamma(c), especially the du gamma(c)-b form, was associated with expression of Th17-related cytokines during R. anatipestifer infection. (C) 2017 Elsevier Ltd. All rights reserved.