Interferon-inducible transmembrane (IFITM) proteins are host cell derived restriction factors. These proteins act as the cells first line of defense against invading viral pathogens. Mammalian IFITM proteins have been shown to confer antiviral resistance when challenged with a variety of both enveloped and non-enveloped viruses. For the first time, we are able to demonstrate the anti-viral role that chicken (chIFITM ) proteins play in restricting avian viruses in the host cell.
We are able to report detailed characterisation of new cell lines that allow for the high-throughput assessment of chIFITM-mediated restriction of a diverse range of avian virus. We have successfully generated stably overexpressing immortalized chick embryonic cells that express chIFITM1, 2, 3. We have also generated a Crispr edited DF-1 cell line that lacks the entire chIFITM locus (chIFITM1, 2, 3 and 5). Challenge of these cell lines with a diverse range of avian viruses including influenza A virus (IAV), infectious bronchitis virus (IBV) and Mareks disease virus (MDV) has enabled assessment of chIFITM mediated-restriction of viral replication in vitro. In addition to assessing chIFITM-mediated viral restriction in vitro, we have also characterised IFTM loci from a diverse range of chicken breeds, including indigenous breeds known to be naturally resistant to viral infection. We hypothesize that strong immune pressure in these breeds has driven mutation within the chIFITM locus; accounting for their resistance to viral pathogens.
It is estimated that poultry will be the major global source of meat by 2018 and will account for 46% of meat consumed by 2022. However, infectious diseases are a continuous threat to poultry industry. With over 60 billion chickens produced annually, it is vital that the poultry industry is protected so that food security is maintained.