流感病毒PR8F的拯救及其对BALB／c小鼠的致病力

Rescue of influenza virus PR8F and pathogenesis in BALB/c mice

为了研究H1N1流感病毒对BALB/c小鼠的致病相关分子机制、传播机制以及开发新型疫苗,将本实验室保存的A/PR/8/34株的8个质粒参照Paulina构建的流感病毒8质粒突变系统做定点突变,利用反向遗传操作技术,成功拯救出H1N1流感病毒突变株PR8F。将PR8F株以106 TCID50/100μL的剂量滴鼻感染BALB/c小鼠,观察小鼠临床表现及体质量变化。解剖攻毒后不同时间小鼠并观察体内主要脏器的病理特征,提取各脏器RNA,通过实时荧光定量PCR方法,检测PR8F株在小鼠体内不同脏器中的病毒残留量和在BALB/c小鼠肺脏中的扩增效率。结果表明,H1N1流感病毒突变株PR8F感染小鼠4~7d后全部致死;PR8F株在小鼠体内各脏器中的病毒残留量有很大差异,肺脏中最多,且病毒在肺脏内呈指数形式扩增。本试验建立了H1N1流感病毒PR8F株对BALB/c小鼠的感染模型,为H1N1流感病毒致病机制和传播机制的研究奠定基础。

To explore the pathogenesis and transmission mechanism of influenza virus PR8F in the BALB/c mice so as to serve the development of new vaccines, the 8 plasmids （A/PR/8/34,stored in our lab） were point specifically mutated according to the eight-plasmid mutation system of influenza virus founded by Paulina. A mutation PR8F of HIN1 influenza virus were rescued by re- verse genetics. Mice were inoculated with mutation PRSF of influenza virus at dose of 10^6 TCID50/ 100μL by the nasal cavity. The clinical manifestation and body weight changes were monitored. All the mice died at 4-7 days post inoculation. The main organs were obtained and pathological sections were observed. Viral RNA was extracted and then detected by qPCR for the virus residue of mutation PR8F in the organs and its amplification efficiency in lung. The result indicated that the mutation PRSF had a 100% mortality rate in mice;there were significant differences in the amount of viral residues in different mice organs. The virus retained the most in lung and copied in exponential form. The mouse infection model of influenza virus （H1N1） mutation has been successfully established which can lay a foundation for the study of the pathogenesis and transmission mechanism of HIN1 influenza virus.