Gene Expresssion of Cytokine and Toll-like Receptor Signaling molecule mRNA in Peripheral Blood Mononuclear Cells (PBMCs) from Pigs Co-infected with Porcine Reproductive and Respiratory Syndrome Virus and Porcine Circovirus

Abstract

      Field and experimental studies have shown that co-infection of PRRSV and PCV2 in pigs were quite common and thus the interactions between both viruses in the host might be critical to the pathogenesis of the disease. The exact interaction mechanisms are unknown and remained to be elucidated. In this study, the expression of cytokine mRNA as well as Toll like receptor signaling molecules associated with innate immunity in peripheral blood mononuclear cells (PBMCs) from pigs infected with PRRSV and/or PCV2 were investigated. Cytokine mRNA and TLR signaling molecule expression were determined by quantitative real-time polymerase chain reaction. Co-infection of pigs with PRRSV and PCV2 led to up-regulated expression of IL-1β and IL-10 mRNA and down-regulated expression of TNF-α and IL-6, IFN-α and IFN-β in PBMCs of pigs co-infected with PRRSV and PCV2. An increased expression of CD14 mRNA was noticed in pigs co-infected with PRRSV and PCV2. A down-regulated expression of IRF-1 and IRF-3 mRNA might also suppress the expression of IFNs that leads to the enhanced replication of PCV2 in pigs co-infected with PRRSV and PCV2.