1. Department of Animal Sciences, Washington State University, Pullman, WA 99164-6351, USA
2. Ministry of Education's Key Laboratory for Agricultural Animal Genetics, Breeding and Reproduction, and Ministry of Agriculture's Key Laboratory for Swine Genetics and Breeding, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, PR China
3. Animal Parasitic Diseases Laboratory, ANRI, ARS, USDA, BARC-East, Beltsville, MD 20705, USA
Secretion of interferons (IFNs) from virus-infected cells is a hallmark of host antiviral immunity and in fact, IFNs exert their antiviral activities through the induction of antiviral proteins. The IFN-induced protein with tetratricopeptide repeats (IFITs) family is among hundreds of IFN-stimulated genes. This family contains a cluster of duplicated loci. Most mammals have IFIT1, IFIT2, IFIT3 and IFIT5; however, bird, marsupial, frog and fish have only IFIT5. Regardless of species, IFIT5 is always adjacent to SLC16A12. IFIT family genes are predominantly induced by type I and type III interferons and are regulated by the pattern recognition and the JAK-STAT signaling pathway. IFIT family proteins are involved in many processes in response to viral infection. However, some viruses can escape the antiviral functions of the IFIT family by suppressing IFIT family genes expression or methylation of 5' cap of viral molecules. In addition, the variants of IFIT family genes could significantly influence the outcome of hepatitis C virus (HCV) therapy. We believe that our current review provides a comprehensive picture for the community to understand the structure and function of IFIT family genes in response to pathogens in human, as well as in animals.
Keywords: IFIT family, evolution, antiviral activities, regulation and signaling, therapy of infectious diseases.