Porcine arterivirus entry in macrophages: heparan sulfate-mediated attachment, sialoadhesin-mediated internalization, and a cell-specific factor mediating virus disassembly and genome release.

摘要

1. INTRODUCTION Porcine reproductive and respiratory syndrome (PRRS) was first described as a new disease in pig herds in North America late in the 1980s and beginning of the 1990s in Europe and is characterized by respiratory disease in young piglets and late-term reproductive failure. The causative agent of the disease was identified in Europe in 1991 and in the US in 1992 as a virus, PRRS virus (PRRSV). PRRSV is classified with equine arteritis virus (EAV), lactate dehydrogenase-elevating virus (LDV), and simian hemdrrhagic fever virus (SHFV) in the family Arteriviridae, which is grouped with the Coronaviridae and the Roniviridae in the order Nidovirales.The virus is an enveloped particle with a diameter of 50 to 65 nm and contains a polyadenylated, positive-strand RNA genome. The genome is about 15 kDa and encodes 9 open reading frames: ORFla and lb code for nonstructural proteins, ORF2a, 2b, 3, 4, 5 and 6 code for structural membrane proteins, and ORF7 codes for the nucleocapsid protein (N).