猪繁殖与呼吸综合征病毒CD163受体功能域鉴定

Identification of the CD163 receptor domains related to porcine reproductive and respiratory syndrome virus infection

猪繁殖与呼吸综合征是危害养猪业重要传染病之一,CD163是猪繁殖与呼吸综合征病毒(PRRSV)感染易感细胞受体。研究表明CD163受体的前2个SRCR区域与PRRSV感染无关。为确定PRRSV感染细胞过程中CD163受体关键SRCR区域,构建表达野生型CD163受体和缺失不同个数SRCR区域的CD163受体突变体质粒。将质粒转染BHK-21细胞24 h后,XH-GD株PRRSV感染细胞,进行间接免疫荧光(IFA)观察。结果显示,CD163前4个SRCR重复区缺失不影响PRRSV感染,SRCR5是PRRSV感染细胞所必须。为进一步研究CD163受体在PRRSV感染Marc-145细胞过程中的作用及与其他受体之间相互关系提供试验基础。

Porcine reproductive and respiratory syndrome virus （PRRSV） had been acknowledged as one of the most important agents affecting swine industry. The scavenger receptor CD163 was one of the important entry mediators for PRRSV infection. To identify which SRCRs in CD163 were involved in this function, CD163 or Dx CD163 deletion mutants were cloned to eukaryotic expression vector pcDNA3.1-Myc-His, then the pcDNA3.1-Dx CD163 （x=0-8） plasmid were transfected into BHK-21 cells using Lipofectamine 2000. The plasmid transfected cells at 24 h post-transfection were infected with XH-GD strain of PRRSV. After 1 h adsorption period, inocula were removed and cells were washed with PBS. After an additional incubation for 24 h at 37 ℃, cell monolayers were observed and analysed by IFA. The result showed that the first four SRCR repeats of CD163 were not required for PRRSV receptor activity, and SRCR5 was essential for PRRSV infection. The results lay foundation for analyzing the function of CD163 as PRRSV receptor in cultured cell.