Porcine reproductive and respiratory syndrome (PRRS): an immune dysregulatory pandemic

Abstract

Porcine reproductive and respiratory disease syndrome (PRRS) is a viral pandemic that especially affects neonates within the "critical window" of immunological development. PRRS was recognized in 1987 and within a few years became pandemic causing an estimated yearly $600,000 economic loss in the USA with comparative losses in most other countries. The causative agent is a single-stranded, positive-sense enveloped arterivirus (PRRSV) that infects macrophages and plasmacytoid dendritic cells. Despite the discovery of PRRSV in 1991 and the publication of >2,000 articles, the control of PRRS is problematic. Despite the large volume of literature on this disease, the cellular and molecular mechanisms describing how PRRSV dysregulates the host immune system are poorly understood. We know that PRRSV suppresses innate immunity and causes abnormal B cell proliferation and repertoire development, often lymphopenia and thymic atrophy. The PRRSV genome is highly diverse, rapidly evolving but amenable to the generation of many mutants and chimeric viruses for experimental studies. PRRSV only replicates in swine which adds to the experimental difficulty since no inbred well-defined animal models are available. In this article, we summarize current knowledge and apply it toward developing a series of provocative and testable hypotheses to explain how PRRSV immunomodulates the porcine immune system with the goal of adding new perspectives on this disease.

Mechanisms of Adaptive Immunity to Porcine Reproductive and Respiratory Syndrome Virus

“…PRRSV modulation of intracellular antiviral defense mechanisms has been reviewed extensively [79]. The effects of PRRSV infection on adaptive immune response, i.e., antigen-specific T cell, B cell, and antibody responses, are less well characterized.…”

Proteomic Analysis of the Secretome of Porcine Alveolar Macrophages Infected with Porcine Reproductive and Respiratory Syndrome Virus

“…PRRSV infection suppresses the host immune response . For example, PRRSV inhibits synthesis of type I interferon (IFN) in pigs.…”

A multiplex real-time PCR panel assay for simultaneous detection and differentiation of 12 common swine viruses

“…In the system of intensive swine production, syndromic diseases including respiratory, enteric, vesicular, and reproductive diseases are often causing different levels of morbidity and mortality, leading to significant economic losses (Butler et al, 2014;Garner et al, 2002;Jung and Saif, 2015;Kleiboeker, 2002;Ma et al, 2015). Within a given syndromic disease, clinical signs caused by different pathogens can be very similar.…”