Molecular analysis of chicken interferon-alpha inducible protein 6 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 IFI6 (ch IFI6 ) was identified and studied for its molecular features and transcriptional regulation in chicken cells and tissues, i.e., lungs, spleens, and tracheas from highly pathogenic avian influenza virus (HPAIV)-infected chickens. The ch IFI6 -coding sequences contained 1638 nucleotides encoding 107 amino acids in three exons, whereas the duck IFI6 -coding sequences contained 495 nucleotides encoding 107 amino acids. IFI6 proteins from chickens, ducks, and quail contain an IF6/IF27-like superfamily domain. Expression of ch IFI6 was higher in HPAIV-infected White Leghorn chicken lungs, spleens, and tracheas than in mock-infected controls. TLR3 signals regulate the transcription of ch IFI6 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 IFI6 . Further research is needed to unravel the molecular mechanisms underlying IFI6 transcription, as well as the involvement of ch IFI6 in the pathogenesis of HPAIV in chickens.