The knowledge gained from species comparisons can be used to develop sustainable strategies to control avian influenza in poultry
Researchers at the Roslin Institute have identified immune processes and key genes that may play a part in how various bird species respond to infection with avian influenza viruses. They hope the outcomes from their study, published in Frontiers in Cellular and Infection Microbiology, may help inform development of commercial poultry that are resistant to the disease.
Researchers examined the response to low pathogenic and highly pathogenic avian influenza viruses in six bird species – chicken and turkey, which are susceptible to the disease, duck and crow, which tolerate and spread disease, and goose and pigeon, which are known to be highly resistant. The team sought to pinpoint biological differences that affect the outcomes of infection.
In chickens and turkeys, exposure was found to lead to very high amounts of virus accumulating in several organs including the brain. It is suggested that this impact on the brain may be the cause of morbidity and mortality in these species.
Pigeons, which are resistant to infection, had low amounts of virus in their bodies and showed a low immune response following exposure to the virus suggesting that they have an inherent ability to prevent virus from entering cells or spreading.
The researchers suggest that pigeons may be protected by having high levels of interferon-stimulated genes, which are involved in immune response to infection. The study identified other genes that may have a role in resistance, including several linked to the nervous system.
Genetic differences identified may explain a variation in how ducks and crows, which typically show similar responses to infection, differ in their reaction to some strains of highly pathogenic avian influenza virus.
The results also highlighted the benefits of a fast innate immune response to infection, as delayed reactions tend to lead to worse outcomes.
Article: Morris, K.M., Mishra, A., Raut, A.A., Gaunt, E.R., Borowska, D., Kuo, R.I., Wang, B., Vijayakumar, P., Chingtham, S., Dutta, R., Baillie, K., Digard, P., Vervelde, L., Burt, D.W., Smith, J., 2023. The molecular basis of differential host responses to avian influenza viruses in avian species with differing susceptibility. Frontiers in Cellular and Infection Microbiology, 13:1067993, doi: 10.3389/fcimb.2023.1067993