1株抗肿瘤新城疫病毒的毒力分析

Virulence Analysis of an Anti-tumor Newcastle Disease Virus Strain

[目的]分析1株抗肿瘤新城疫病毒(NDV)的毒力。[方法]通过传统毒力的测定方法,测定此株NDV的最小致死量的平均死亡时间(MDT)、脑内致病指数(ICPI)及静脉致病指数(IVPI)。通过RT-PCR扩增此株病毒基因组的多个片段,相邻扩增片段之间有部分核酸序列重叠且覆盖完整的融合蛋白(F)基因和血凝素神经氨酸酶(HN)基因的区域,并进行测序。[结果]此株NDV的MDT为105.6h,ICPI约为0.26,IVPI为0。测序结果表明,此株病毒是1株新的NDV,其F蛋白剪切位点为112RRQRRF117。[结论]此株NDV为弱毒株,其F蛋白剪切位点与强毒株一致。除F蛋白剪切位点外,NDV的毒力必然与其他因素相关。

[ Objective ] To analyze the virulence of an anti-tumor newcastle disease virus （NDV） strain. [ Method ] Its mean death time of chicken embryos（MDT）, intraccrebral pathogenicity index （1CPI） in one-day-old chicks and intravenous pathogenicity index（1VPl） in 6-week-old chickens were determined by traditional assay method of virulence. The multiple fragments of the virus genome were amplified by RT-PCR and there were some overlapping nucleic acid sequences between these fragments covering the complete fusion protein （F） gene and the hemaggluti- nin neuraminidase （ HN）, these fragments were sequenced. [ Result ] This NDV strain＇ s MDT was 105.6 h, its ICPI was approximately 0.26 and its 1VP1 was 0. Sequencing indicated that the virus was new and its cleavage site of F protein was H2RRQRRFH7. ~Conclusion]This NDV strain was low virulent strain and its cleavage site of F protein was the same as the virulent strain, indicating that the NDV virulence inevitably was associated with other factors except the cleavage site of F protein.