Characterization of chicken interleukin-9 receptor alpha chain

Interleukin-9 receptor alpha chain (IL-9Ra) is the ligand-binding subunit of IL-9R that plays roles in IL-9-mediated allergy, inflammation, infection, and tumor immunity. While mammalian IL-9Ras have been extensively investigated, avian IL-9Ra has not yet been identified and characterized. In this study, we cloned chicken IL-9Ra (chIL-9Ra) and performed a phylogenetic analysis, analyzed its tissue distribution, characterized the expression form of natural chIL-9Ra. Phylogenetic analysis showed that chIL-9Ra has less than 25% amino acid homology with mammalian IL-9Ras. The chIL-9Ra mRNA was abundantly detected only in heart and mitogen-activated peripheral blood mononuclear cells. Furthermore, 4 monoclonal antibod-ies (mAbs) against chIL-9Ra were generated using pro-karyotic recombinant chIL-9Ra (rchIL-9Ra). Using anti-chIL-9Ra mAbs, natural chIL-9Ra expressed on the splenocytes of chickens was observed by indirect immunofluorescence assay (IFA), and its molecular weight of 51 kDa was identified by Western blotting. Overall, our study reveals for the first time the presence of IL-9Ra in birds, and provides immunological tools for further investigating the roles of chIL-9 in diseases and immunity.

Automated summary

This study discovered the presence of interleukin-9 receptor alpha chain (IL-9Ra) in birds, which plays important roles in allergy, inflammation, infection, and tumor immunity. The chicken IL-9Ra (chIL-9Ra) was cloned and its tissue distribution and expression form were characterized. Monoclonal antibodies against chIL-9Ra were generated and used to detect its expression on chicken splenocytes. This study provides important immunological tools for further investigation of the roles of chIL-9 in diseases and immunity.