Location: Virus and Prion ResearchTitle: Effects of adenoviral delivered interferon-alpha on porcine reproductive and respiratory syndrome virus infection in swine
Submitted to: North American Porcine Reproductive and Respiratory Syndrome (NA-PRRS) Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 10/13/2015
Publication Date: N/A
Technical Abstract: Type I interferons, such as interferon (IFN) alpha, contribute to innate antiviral immunity by promoting production of antiviral mediators and also play a role in the adaptive immune response. Porcine reproductive and respiratory syndrome (PRRS) has been shown to induce a meager IFN-alpha response. We administered porcine IFN-alpha using a replication-defective adenovirus vector and challenged with a moderately virulent PRRSV. There was a better clinical outcome in pigs treated with IFN-alpha, including lower febrile responses and decreased percentage of lung involvement. Viremia was delayed and there was a decrease in viral load in the sera of pigs treated with IFN-alpha. In addition, there was an increase in the number of virus-specific IFN-gamma secreting cells, as well as an altered cytokine profile in the lung 14 days post-infection, indicating that the presence of IFN-alpha at the time of infection can alter innate and adaptive immune responses to PRRSV. In a subsequent experiment we further explored the use of IFN-alpha as an adjuvant given with attenuated PRRSV virus vaccine and found that it was able to totally abolish replication of the vaccine virus resulting in no seroconversion. Current studies are examining its use as a metaphylactic treatment for an outbreak of PRRSV to both treat and prevent spread of the virus. The use of immunomodulators is a promising area for therapeutic, prophylactic, and metaphylactic use to prevent and combat infectious disease.