猪繁殖与呼吸综合征病毒和猪圆环病毒2型共感染对外周血单个核细胞凋亡细胞因子mRNA表达的影响

Effects of porcine reproductive and respiratory syndrome virus and porcine circovirus type 2 co-infection on apoptogenic cytokine mRNA expression in peripheral blood mononuclear cells of piglets

将猪繁殖与呼吸综合征病毒(Porcine reproductine and respiratory syndrome virus,PRRSV)和猪圆环病毒2型(Porcine circovirus type 2,PCV2)单感染和共感染6周龄健康仔猪,采用real-ti me PCR技术对外周血单个核细胞(PBMC)中的病毒载量以及Fas、FasL、TNFR1和TNF-α等凋亡细胞因子mRNA表达水平进行检测,采用流式细胞术对PBMC的凋亡比率进行检测。结果显示,PRRSV/PCV2共感染组PBMC中PRRSV和PCV2载量、PB-MC凋亡比率均显著高于PRRSV感染组或PCV2感染组。所有病毒感染组的Fas、FasL、TNFR1和TNF-α的mRNA表达水平均显著上调,并且PRRSV/PCV2共感染组的表达水平均显著高于单感染组。结果表明,Fas/FasL、TNFR1/TNF-α表达水平的显著上调可能在PRRSV和PCV2协同诱导凋亡机制中扮演重要角色。

Six-week-old healthy piglets were experimentally inoculated with porcine reproductive and respiratory syndrome virus （PRRSV） or porcine circovirus type 2 （PCV2） alone or in combination （PRRSV and PCV2）. The viral loads and the levels of mRNA expression for apoptogenic cytokines,i, e. Fas,FasL,TNFR1 and TNF-α,in peripheral blood mononuclear cells （PBMC） were measured by real-time PCR. The percentages of apoptosis of PBMC were detected by flow cytometry. The results showed that the ：piglets co-infected with PRRSV and PCV2 exhibited significantly higher amounts of both PRRSV and PCV2 in PBMC,and significantly higher percentages of apoptosis of PBMC,in comparison to the piglets infected with either virus alone. All virus-infected groups showed significant upregulation of gene expression of Fas,FasL,TNFR1 and TNF-α in PBMC compared to the control group. Furthermore, the PRRSV and PCV2 co-infected group showed significantly increased levels of mRNA expression of Fas, FasL, TNFR1 and TNF-α,in comparison to the PRRSV- or PCV2 group. These results suggest tlaat the markedly increased expression of Fas,FasL,TNFR1 and TNF-α may play an important role in the synergistic induction of a＇poptosis by PRRSV and PCV2 co-infection.