狂犬病病毒HEP-FluryM基因重排在小鼠致病性和保护性研究

Objective To understand the impact of M gene rearrangement on the pathogenicity and immune protection of the virus, so as to provide more suitable candidate strains for the development of rabies vaccines. Methods The viruses rHEP - Flury and the M gene rearrangement strain were intracranially inoculated into suckling mice aged 1 - 3 days, and the median lethal dose (LD_(50)) of the virus in the suckling mice was determined. The rHEP - Flury and the M gene rearrangement strain were immunized into adult mice aged 6 - 8 weeks at doses of 10~3, 10~4 and 10~5 FFU, and then the mice were intracranially infected with the standard challenge strain CVS - 24, and the survival rate of the mice was determined. At the same time, the serum antibody levels of the mice were detected by ELISA. Results After the M gene rearrangement of the rabies virus HEP - Flury, the virulence of the virus to suckling mice increased as the position of the M gene was farther away from the position of the virus promoter, that is, M2 < rHEP - Flury < M4. When the inoculation dose was 10~4 and 10~5 FFU, the M gene rearrangement had no statistically significant impact on the protection of the virus in adult mice; when the inoculation dose was 10~3 FFU, the protection of the M gene rearrangement virus to mice was significantly higher than that of rHEP - Flury. Conclusion The M gene rearrangement of the rabies virus HEP - Flury can reduce the virulence of the virus to suckling mice and improve the protection to mice, laying a foundation for the development of rabies vaccines.

目的了解M基因重排对病毒致病性和免疫保护性的影响,从而为狂犬病疫苗的开发提供更适合的候选株。方法将病毒rHEP-Flury和M基因重排株颅内接种1~3d龄的乳鼠,测定病毒在乳鼠上的半数致死量(LD_(50))。将rHEPFlury和M基因重排株以10~3、10~4和10~5 FFU免疫接种6~8周龄的成鼠,然后用标准攻毒株CVS-24进行颅内感染小鼠,测定小鼠的存活率。同时用ELISA方法检测小鼠血清抗体水平。结果狂犬病病毒HEP-Flury的M基因重排后,病毒对乳鼠的毒力随着M基因位置远离病毒启动子位置增强,即M2<rHEP-Flury<M4。当接种剂量为10~4和10~5FFU时,M基因重排对病毒在成鼠上的保护性没有统计学意义影响;当接种剂量为10~3FFU时,M基因重排病毒对小鼠的保护性明显高于rHEPFlury。结论狂犬病病毒HEP-Flury的M基因重排能够降低病毒对乳鼠的毒力,提高对小鼠的保护性,为狂犬病疫苗开发奠定基础。