PCV2人工感染对猪肺泡巨噬细胞干扰素信号通路的调控研究

Regulation of Interferon Signaling Pathway in Alveolar Macrophages of Piglets Infected with Procine Circovirus Type 2

通过建立PCV2亚临床感染模型,探究感染仔猪肺泡巨噬细胞中干扰素的变化及其调控,为PCV2复制和发病机制研究提供补充。30日龄猪圆环病毒2型(PCV2)和猪繁殖与呼吸综合征病毒(PRRSV)抗原和抗体均为阴性的仔猪15头,随机分成PCV2阴性对照0d组、PCV2感染14d组和PCV2感染28d组。感染后荧光定量PCR方法检测肺泡巨噬细胞中干扰素、模式识别受体和模式识别受体接头分子mRNA水平。结果显示,IFN-β和IFN-γmRNA转录水平在14和28d均显著高于对照组(P<0.05);模式识别受体RIG-1、MDA-5、TLR4和TLR9mRNA转录水平在14和28d显著升高(P<0.05);DAI mRNA转录水平在14d显著升高(P<0.05),但28d迅速下降;TLR3、TLR7和TLR8mRNA转录水平无明显变化。接头分子MAVS、MyD88、IRF3和IRF7mRNA转录水平在14和28d均显著高于对照组(P<0.05)。以上结果表明,PCV2亚临床感染仔猪后导致肺泡巨噬细胞内IFN-β和IFN-γ的表达量上调,其上调和PCV2激活的TLR4/TLR9/MyD88和RIG-1/MDA-5/DAI/MAVS/IRF3信号通路有关。

To understand the mechanism of PCV2 replication and pathogenesis,change and regulation of interferon in alveolar macrophages of piglets subclinically infected with procine circovirus type 2（PCV2）were studied.Fifteen 30-day-old piglets were selected as experiment animals,which were free of PCV2 and porcine reproductive and respiratory syndrome virus（PRRSV）antibody and antigen.The piglets were divided into three groups：control group（0dpi）,PCV2 infection group（14dpi）and PCV2 infection group（28dpi）.After infection,the mRNA transcription of interferon,pattern recognition receptors（PRRs）and pathogen associated molecular proteins（PAMPs）in AMs were detected by real-time PCR.The results showed that the mRNA levels of IFN-βand IFN-γwere significantly higher at 14 dpi and 28dpi（P〈0.05）;the mRNA expression of RIG-1,MDA-5,TLR4 and TLR9were significantly increased at 14 dpi and 28dpi（P〈0.05）;the mRNA level of DAI was significantly elevated at 14dpi（P〈0.05）,and then decreased at 28dpi;while there were no significant change in mRNA expression of TLR3,TLR7 and TLR8.Com-pared with control,the mRNA transcription of MAVS,MyD88,IRF3 and IRF7were significantly increased at 14 dpi and 28dpi（P〈0.05）.These results demonstrate that the up-regulations of IFN-βand IFN-γin alveolar macrophages of PCV2 subclinical infection are relative to TLR4/TLR9/MyD88 and RIG-1/MDA-5/DAI/MAVS/IRF3 signaling pathways.