利用ICR小鼠模型对PCV2感染中TLR3信号通路的研究  

Signal pathway of TLR3 induced by Procine circovirus type 2 in spleen of ICR mice

作　　者：姜雪婷 黄立平[2] 王伟[2] 危艳武[2] 刘赛宝 鲁国涛 刘长明[2] 孟庆文[2] 陈洪岩[1,2] 

机构地区：[1]东北农业大学生命科学学院,黑龙江哈尔滨150030 [2]中国农业科学院哈尔滨兽医研究所兽医生物技术国家重点实验室,黑龙江哈尔滨150069

出　　处：《中国预防兽医学报》2017年第10期820-825,共6页Chinese Journal of Preventive Veterinary Medicine

基　　金：兽医生物技术国家重点实验室开放基金课题(SLLVBF201511);兽医生物技术国家重点实验室基本科研业务费(SKLVBP2015010);地方科技攻关计划课题(PC13S16);地方科技攻关计划课题(2014QA3BN002)

摘　　要：为探究猪圆环病毒2型(PCV2)感染对TLR3信号通路及炎性细胞因子的影响,本研究将30只6周龄ICR雌鼠随机分成两组(感染组和对照组),腹腔接种PCV2b/YJ株,在接种后第7 d、14 d、21 d、28 d和35 d采集小鼠外周血及脾组织。以临床观察、脾组织PCV2基因拷贝、小鼠血清抗体效价、IL-10和TNF-α的mRNA水平等指标评估感染模型;荧光定量PCR检测小鼠脾组织TLR3、TRIF、IFN-β、Mx1的mRNA水平,western blot检测TLR3蛋白表达水平。结果显示:PCV2感染期间感染组小鼠无可见的临床症状,第7 d至35 d感染组小鼠脾组织PCV2基因拷贝数呈逐渐降低趋势,PCV2的IPMA血清抗体在感染后第7 d转阳、35 d达到最高,IL-10 mRNA在感染后第14 d起升高、维持高水平;TNF-αmRNA在感染后第21 d和28 d升高。在感染后第7 d和14 d感染组小鼠TLR3、TRIF mRNA和TLR3蛋白表达水平显著升高;IFN-βmRNA在感染后第7 d具有显著升高过程;Mx1 mRNA在感染后第14 d时有上调过程。本实验在建立PCV2b/YJ亚临床感染ICR小鼠模型的基础上,体内实验表明PCV2感染小鼠激活了TLR3信号通路。本研究为利用敲除小鼠模型阐明TLR3参与PCV2感染引发的免疫应答机制奠定了基础。To investigate the effect of porcine circovirus type 2 （PCV2） infection on TLR3 signaling pathways and inflammatory cytokines, 30 ICR mice were divided into two groups randomly （experiment group and control group）, experiment group was inoculated with PCV2 via the intraperitoneal route, and peripheral blood and spleen of the mice were collected at 7, 14, 21, 28 and 35 days post infection （dpi）. The infection model was assessed by clinical signs, DNA copies of the PCV2 in spleen, antibody titers in serum, and the mRNA transcription of IL-10 and TNF-α in mice. The mRNA transcript levels of TLR3, TRIF, IFN-β and Mxl in spleen of the mice were detected by quantitative real-time RT-PCR, and the protein expression of TLR3 in mice was measured by western blot. Results showed that no obvious clinical signs compatible with PCV2 were observed on ICR mice. The copy number of PCV2 gene in spleen tissue of 7dpi to 35dpi tended to decrease gradually. Antibody of mice against PCV2 was monitored by IPMA method at 7dpi and reached the peak at 35dpi. The mRNA levels of IL-10 in mice increased at 14dpi and maintained a high level. The mRNA levels of TNF-α in mice increased at 21dpi and 28dpi. The mRNA of TLR3, TRIF and the protein of TLR3 in mice significantly increased at 7dpi and 14dpi. The mRNA levels of IFN-β in mice significantly increased at 7dpi, and Mxl slightly increased at 14dpi. In conclusion, on the basis of establishing ICR mice model infected by PCV2, the experimental results indicated TLR3 signal pathway was activated by PCV2 infection in vivo. It laid a foundation for elucidating the mechanism of TLR3 involved in the immune response induced by PCV2 infection using the knockout mice.

关 键 词：PCV2感染 ICR小鼠 TLR3信号通路 细胞因子 

分 类 号：S852.65[农业科学—基础兽医学]