Date Full Report Received07/15/2011
Date Abstract Report Received07/15/2011
Funded ByNational Pork Board
Knowing the composition and structure of PRRSV is an important prerequisite for development of immunological prevention and control strategies, just as knowing what a spark plug looks like is important when you need to replace it. The surface of a PRRSV virion is covered with a small amount of envelope proteins, and a large amount of carbohydrate sugars (glycan) that are attached to the proteins. The glycan shield is the primary structure encountered by antibodies, other host defense molecules, and the surface of permissive cells. Since the interaction of a virus and the host is based on interactions of molecular structures, it is important to know what these structures are, and to determine what roles they play. Here, we used several approaches to dissect the glycan shield of PRRSV and deduce the significance for interactions with cells that are permissive for infection. The glycans are primarily on the major envelope protein, GP5, and have complex structures dominated by terminal glucosamine, lactosamine and sialic acid sugars. Proteins that bind to these specific terminal sugars reduce viral infectivity. However, it appears that the interference may be due to steric hindrance, suggesting that the sugars themselves do not have a direct role in virus-host cell interactions.