Cytokine responses in pigs after natural infection with classical swine fever virus

Classical swine fever (CSF) is a highly contagious viral infection that affects domestic and wild pig population. The classical swine fever virus (CSFV) targets immune cells which perturb the immune functions causing immunopathological disorders such as immunosuppression, leukopenia and haemorrhage. In the present study, ELISA and quantitative real-time reverse transcription PCR (qRT-PCR) analysis was employed to determine cytokine profiles in pigs naturally infected with CSFV using whole blood assay (WBA) under field conditions. Significantly higher TNF-α, IL-10, and IL-6 expression levels were found in unvaccinated pigs infected with CSFV (group B) compared to vaccinated pigs that recovered after CSF (group A), the difference being statistically significant (p = 0.001). However, the expression of IFN-γ was significantly higher in group A compared to group B (p = 0.001). The findings of this field-supported study will help us to understand the immune biology of CSFV infection in infected pigs. The WBA technique can be used as a reliable, fast and feasible in vitro method to assess porcine cellular immune responses as it imitates the porcine blood conditions. Such studies could be of some value in determining the immune status of the ailing animals infected with CSFV. Keywords: classical swine fever virus; immune response; field conditions; interleukin; IFN-γ; TNF-α.