摘要
目的对狂犬病病毒CTN-181弱毒株经豚鼠颌下腺传代和空斑纯化而获得的3株弱毒株病毒（CTN-1-3,CTN-1-16和CTN-1-19）进行全面的致病性、免疫性研究和遗传稳定性研究。方法分别对3株病毒用10、14和21日龄小鼠脑内接种,观察小鼠的发病死亡情况进行致病性研究;分别对3株病毒用3周龄小鼠进行肌内免疫和口腔免疫,测定小鼠中和抗体阳转率和中和抗体水平;将3株病毒在乳鼠脑内连续传代或豚鼠颌下腺传代,传代后病毒以小鼠脑内接种观察有无致病性进行遗传稳定性研究。结果在致病性方面：3株病毒均对3周龄小白鼠脑内接种无致病性,其中CTN-1-3和CTN-1-19对14日龄乳鼠约半数存活,而CTN-1-16株则大部分死亡。对10日龄乳鼠只有CTN-1-3株不完全致死。在免疫性方面：3株病毒以≥5.5lg PFU病毒肌内免疫或≥6.5lg PFU口腔免疫的3周龄小鼠,30d后的中和抗体阳转率均为100%,GMT分别为7.0～16.1IU/ml和7.9～39.5IU/ml。在遗传稳定性方面,3株病毒经1～3日龄乳鼠脑内连续传5代或豚鼠颌下腺传1代,传代增殖后的病毒滴度虽高达6.5或8.0lg PFU/ml,对小鼠脑内接种仍保留无致病力的弱毒特性。结论结果表明3株病毒的毒力已高度减弱,免疫效力良好,诱生的抗体水平很高,遗传稳定性十分稳定,是研发兽用狂犬病口服活疫苗和狂犬病暴露后人体免疫用减毒活疫苗的良好候选株。
Objective To study the pathogenicity, immunogenicJty and neuroattenuation stability of three attenuated rabies virus strains （CTN-1-3, CTN-1-16 and CTN-1-19）, isolated by plaque cloning from the submandibular gland of CTN-181 attenuated virus infected guinea pigs. Methods Pathogenicity was performed by intracerebral （ic） inoculation of different ages of mice （10 d, 14 d and 21 d） with different doses of virus of the CTN-1-3 , CTN-I-16 and CTN-I-19 strains, respectively. Immunogenicity was conducted in mice inocula ted orally （o. i. ） or intramuscularly （i. m. ） with the three attenuated viruses, respectively. After 14 days, ic challenged the mice with rabies fixed virus CVS strain. All mice were observed for the mortality rate of rabies at 14 days. Meanwhile on day 14 and day 30 post-vaccination, the serum of each mouse was collected and tested for the presence of virus neutralizing antibodies （VNA） with the rapid fluorescent focus inhibition test （RF- FIT） . To detect the neuroattenuation stability, the three virus strains were passaged in suckling mice brain for five consecutive passages or in submandibular gland of guinea pigs for one passage. Viruses recovered from the brains and glands were tested for the neurovirulence by ic inoculation in mice. Results All of the three virus strains were completely nonpathogenic to 21-day-old mice. The CTN-1-3 and CTN-1-19 were only partially lethal to 14 day-old mice at virus titers of 〉3. 48-3. 98 lg PFU. All mice seroconversed on day 30 postimmunization either by intramuscular route inoculation （i. m. infected with ≥5.5 lg PFU virus） or oral route （o. i. ,infected with 96.5 lg PFU virus） and the neutralizing antibody titers were as high as 7.0-16.1 IU/ml （i. m. ） and 7.9 to 39.5 IU/ml （o. i. ） . After passaging those viruses in suckling mice brains for five consecutive passages or in submandibular glands of guinea pigs for one passage, no virulence reversion was detected. Conclusions The lack or low pathogenicity in young or suckling mice together with excellent immunogenicity and neuroattenuation stability indicate that the three newly selected CTN attenuated virus strains are promising live vaccine candidates for wild animal prophylactic vaccination and even post-exposure prophylaxis of rabies for humans.
作者
邹剑
石磊泰
俞永新
李玉华
ZOU Jian SHI Lei-tai YU Yong-xin LI Yu-hua(Sichuan Institute for Food and Drug Control, Chengdu, Sichuan 610097, China)
出处
《中国病毒病杂志》
CAS
2016年第2期134-139,共6页
Chinese Journal of Viral Diseases
关键词
狂犬病减毒克隆株
致病力
免疫原性
遗传稳定性
Attenuated rabies virus clones
Pathogenicity
Immunogenicity
Neuroattenuation stability
