| Porcine reproductive and respiratory syndrome (PRRS) is characterized by reproductive failure in late-term gestation in sows and respiratory disease in piglets, and PRRSV is its causative agent. PRRS has caused huge losses in swine industry since its world-wide spread in the 1990's.In vivo, PRRSV infects subpopulations of differentiated macrophages, with alveolar macrophages being the major target cells during acute infection. Virus entry operates through a mechanism of receptor-mediated endocytosis, which involves several receptors or coreceptors, including sialoadhesin (Sn), heparin sulfate, CD163 on PAM.To further study the detailed function of cell receptors for PRRSV and the pathogenesis of PRRSV infection, the genes of two key cell receptors in PRRSV infection, CD163 and Sn, were cloned and inserted into two eukaryotic expression vectors pcDNA3.1 and PIREShyg3.0, respectively. After transient transfection of the recombinant pcDNA3.1-CD163 and PIREShyg3.0-Sn into cells, indirect fluorescence assay and virus infection assay were employed to identify the functions of CD163 and Sn during PRRSV infection.The results showed that: Sn and CD163 can mediate endocytosis of PRRSV. After transient transfection Sn or CD163 to PK-15 cell line, it can be infected with PRRSV.This study gives some tentative indications on the molecular mechanism of PRRSV infection on PAM, and may provide certain basis for the study of PRRSV pathogenesis, and the development of novel vaccines, adjuvants and anti-viral drugs. |
