NGS approach to study immune response to PRRS in vitro

Porcine Reproductive and Respiratory Syndrome (PRRS) is one of the most economically important diseases caused by a plus-sense polyadenylated RNA virus (PRRSV). The mechanisms underlying the molecular processes accompanying the PRRS infection, as well as the differences of pathogenicity between different PRRSV strains, remain poorly understood. We used high-throughput deep sequencing approach to get a global view of differentially expressed genes after “in vitro” challenge of Pulmonary Alveolar Machrophages. Infections were performed using two different European type PRRSV strains: Lelystad (low virulence) and Lena (high virulence) viruses. We made a comparative analysis of gene expression profiles to assess the differences of pathogenecity between the two virus strains. Transcript expressions in Lena over-passed those in Lelystad and control, respectively. At the genes level, the main differences between the PRRS virus infection (Lelystad and Lena ) and the control case was centred mainly around “Pattern recognition receptors in recognition of viruses” and “Interferon signalling” canonical pathways. Few genes have been found to be differentially expressed between Lelystad and Lena viruses. Our systems analysis contribute to the understanding of the molecular processes underlying the PRRS virus infection and shed some lights on the differences of pathogenicity between Lena and Lelystad PRRS viruses.