Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/26/2005
Publication Date: 12/1/2005
Citation: Miller, L.C., Chitko McKown, C.G., Laegreid, W.W. 2005. Type I interferon responses to porcine reproductive and respiratory syndrome virus infection [abstract]. International PRRS Symposium. Poster No. 45.
Technical Abstract: Porcine reproductive and respiratory syndrome virus (PRRSV) causes highly significant losses to the swine industry worldwide. Productive infection occurs almost exclusively in cells of the monocyte-macrophage lineage both in vitro and in vivo, predominantly in alveolar macrophages of the lung. Thus, innate immune responses of the alveolar macrophages comprise the initial defense against PRRSV. Previously, we have demonstrated that PRRSV infection does not result in induction of type I interferons (IFN-alpha and -beta) by MARC-145 cells as would be expected with most RNA viruses. The results are significant because both IFN-alpha and IFN-beta are members of the innate immune system which is typically viewed as the first responder of the immune system. Activation of this response signals other branches of the immune system to become activated and mount a protective response. The fact that PRRSV is capable of suppressing the activation of this response may explain the general delayed immune response to PRRSV infection. Further studies on the dynamics of this process, time and dose kinetics and analysis of other genes in the type I interferon pathway are ongoing in primary porcine macrophages. Elucidation of the mechanism of PRRSV suppression of the type I interferon response may provide targets for novel vaccination approaches to control this important disease.