LAUSR

ABSTRACT Interleukin (IL)‐11 plays an important role in the immune system. However, IL‐11 has not yet been characterized in avian species, including chickens. This study is the first to clone and functionally characterize chicken IL‐11 (chIL‐11). Multiple alignments and phylogenetic tree comparisons of chIL‐11 with IL‐11 proteins from other species revealed high levels of conservation and a close relationship between chicken and Japanese quail IL‐11. Our results demonstrate that chIL‐11 was a functional ligand of IL‐11RA and IL‐6ST in chicken HD11 and OU2 cell lines, as well as activated and regulated JAK‐STAT, NF‐&kgr;B, PI3K/AKT, and MAPK signaling pathways in chicken cell lines. In addition, chIL‐11 inhibited nitric oxide production, affected proliferation of both tested cell lines, inhibited Type 1 and 17 T helper (Th) cytokine and IL‐26, IL‐12, and IL‐17A‐induced interferon‐&ggr; production, and enhanced Th2 cytokine (IL‐4 and IL‐10) production. Taken together, functional analysis of chIL‐11 revealed it bound to IL‐11RA and IL‐6ST and activated the JAK‐STAT, NF‐&kgr;B, and MAPK signaling pathways, which resulted in modulation of Th1/Th17 and Th2 cytokine production in chicken HD11 and OU2 cell lines. Overall, this indicates chIL‐11 has a role in both the innate and adaptive immune system. HighlightsCloning and sequence analysis of chicken interleukin 11 (chIL‐11).chIL‐11 has an anti‐inflammatory related to IL‐11RA and IL‐6ST receptor expression.chIL‐11 activated and regulated JAK‐STAT, NF‐&kgr;B, PI3K/AKT, and MAPK signaling pathways.chIL‐11 inhibited nitric oxide production, affected proliferation of both tested cell lines.chIL‐11 inhibited Th1, Th17 cytokine and enhanced Th2 cytokine production.