CYTOKINE mRNA EXPRESSION IN CHICKEN EXPERIMENTALLY INFECTED WITH DIFFERENT AVIAN REOVIRUS STRAINS

Abstract

This study was undertaken to elucidate the cytokine response in chicken infected with strains of avian reovirus (ARV) S1133 and 2408. The expression levels of cytokine mRNA in the spleen and viral S1 RNA in various tissues at 1.5 and 2.5 days post inoculation (dpi) were examined using real-time quantitative PCR. Among the cytokines examined, the mRNA expression levels of IL-6, IFN-γ, IL-10 and iNOS at 2.5 dpi were significantly upregulated and higher in chickens infected with strain 2408 than in chickens infected with strain S1133, particularly IL-6 and IFN-γ. A significantly higher levels of viral S1 RNA were detected in the examined tissues from chickens infected with strain 2408 than with strain S1133 over the experimental course, among which the foot pad and spleen were more predominant. The highest levels of IL-6 and IFN-γ mRNA expression correlated with the viral S1 RNA levels in the spleen and the marked clinical diseases and gross lesions, suggesting that IL-6 and IFN-γ may play a role in the pathogenesis of ARV infection.