Molecular analysis of chicken IFI6 gene and transcriptional regulation

Interferon-alpha inducible protein 6 (IFI6) is an interferon-stimulated gene (ISG), belonging to the FAM14 family of proteins and is localized in the mitochondrial membrane, where it plays a role in apoptosis. Transcriptional regulation of this gene is poorly understood in the context of inflammation  by intracellular nucleic acid-sensing receptors and pathological conditions caused by viral infection. In this study, chicken <italic>IFI6</italic> (ch<italic>IFI6</italic>) was identified and studied for its molecular features and transcriptional regulation in chicken cells and tissues, that is, lungs, spleens, and tracheas from highly pathogenic avian influenza virus (HPAIV)-infected chickens. The ch<italic>IFI6</italic>-coding sequences contained 1638 nucleotides encoding 107 amino acids in three exons, whereas the duck <italic>IFI6</italic>-coding sequences contained 495 nucleotides encoding 107 amino acids. IFI6 proteins in chickens and ducks contain an interferon-alpha inducible protein IF6/IF27-like superfamily domain. Expression of ch<italic>IFI6</italic> was higher in HPAIV-infected White Leghorn chicken lungs, spleens, and tracheas than in mock-infected controls. TLR3 signals regulate the transcription of ch<italic>IFI6</italic> in chicken DF-1 cells via the NF-κB and JNK signaling pathways, indicating that multiple signaling pathways differentially contribute to the transcription of ch<italic>IFI6</italic>. Further research is needed to unravel the molecular mechanisms underlying <italic>IFI6</italic> transcription, as well as the involvement of chIFI6 in the pathogenesis of HPAIV in chickens.