Molecular Characterization, Expression and Functional Analysis of Chicken STING

Abstract

Innate immunity is an essential line of defense against pathogen invasion which is gained at birth, and the mechanism involved is mainly to identify pathogen-associated molecular patterns through pattern recognition receptors. <i>STING</i> (stimulator of interferon genes) is a signal junction molecule that hosts the perception of viral nucleic acids and produces type I interferon response, which plays a crucial role in innate immunity. However, relatively few studies have investigated the molecular characterization, tissue distribution, and potential function of <i>STING</i> in chickens. In this study, we cloned the full-length cDNA of chicken <i>STING</i> that is composed of 1341 bp. Sequence analyses revealed that <i>STING</i> contains a 1140-bp open-reading frame that probably encodes a 379-amino acid protein. Multiple sequence alignments showed that the similarity of the chicken <i>STING</i> gene to other birds is higher than that of mammals. Real-time polymerase chain reaction (PCR) assays revealed that <i>STING</i> is highly expressed in the spleen, thymus and bursa of fabricious in chickens. Furthermore, we observed that <i>STING</i> expression was significantly upregulated both in vitro and in vivo following infection with Newcastle disease virus (NDV). <i>STING</i> expression was also significantly upregulated in chicken embryo fibroblasts upon stimulation with poly(I:C) or poly(dA:dT). Taken together, these findings suggest that <i>STING</i> plays an important role in antiviral signaling pathways in chickens.