猪流感病毒A/swine/Guangdong/2/2012(H1N1)毒株攻毒BALB/c小鼠细胞因子动态变化的研究

为了测定H1N1亚型猪流感病毒(swine influenza virus,SIV)对小鼠的致病性,本试验对A/swine/Guangdong/2/2012(H1N1)株SIV HA基因进行克隆及遗传分析,并将SIV尿囊液经鼻腔感染6周龄BALB/c小鼠,观察感染后小鼠的一般状况、器官系数和组织病理学变化,在病毒感染后第1、3和7天使用荧光定量PCR测定小鼠肺脏、脾脏、脑组织中7种细胞因子mRNA的表达量,研究其对小鼠的致病特性。结果显示,该病毒属于经典SIV,病毒经鼻腔感染后可引起小鼠活动减少、采食量降低,但无咳嗽和死亡;病理组织学变化为肺间隔较正常组织明显增厚,毛细血管明显扩张充血,周围肺泡腔呈代偿性肺气肿;小鼠肺脏、脾脏组织样本中IFN-α、IFN-β、IP-10、IL-1β、TNF-α、IRF-3和IL-10 mRNA含量在感染后第3天均显著升高(P<0.05),而脑组织样本中IL-1β和IL-10在小鼠攻毒后第3和7天均显著上调(P<0.05)。

Dynamic Study of Cytokines in BALB/c Mice Infected with Swine Influenza Virus A/swine/Guangdong/2/2012 (H1N1) Strain

To determine the pathogenicity of the H1N1 swine influenza virus (SIV) to mouse, the HA gene of A/swine/Guangdong/2/2012(H1N1) SIV was cloned,and then genetic analysis was made. The allantoic fluid containing SIV was given to BALB/c mouse that was 6 to 8 months old by nasal infection. General condition, viscera index and histopathological changes of mice were observed and the expression level of 7 kinds of cytokines in the lung, spleen and brain of mice were determined by fluorescence quantitative PCR method at 1,3 and 7 d after infection to determine the pathogenicity. The results revealed that the virus in this study was found to be classical SIV for that it could cause the decline of the activity and feed intake in mice,but no cough and death were showed. Obvious increase was showed in lung interval than the normal tissue. Expansion of congestion was showed in blood capillary, compensatory emphysema could be seen in the surrounding alveolar cavity as well. In the third day after infection,the content of mRNA of cytokines IFN-α,IFN-β,IP-10,IL-1β,TNF-α,IRF-3 and IL-10 showed obvious rising trends while cytokines IL-1β and IL-10 in brain showed the same trend at the third and seventh day after infection.