Role of fusion protein cleavage site in the virulence of Newcastle disease virus.
Role of fusion protein cleavage site in the virulence of Newcastle disease virus.
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DOI：
10.1016/j.micpath.2003.07.003
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发表时间：
2004-01
影响因子：
3.8
通讯作者：
Samal SK
中科院分区：
文献类型：
--
作者：
Panda A;Huang Z;Elankumaran S;Rockemann DD;Samal SK
新城疫病毒（NDV）是一种在家禽中具有高度传染性和重要经济意义的疾病。NDV毒力的病毒决定因素尚未完全了解。融合蛋白蛋白酶裂解位点的氨基酸序列被认为是NDV毒力的主要决定因素。在这项研究中，我们利用反向遗传学技术研究了F蛋白裂解位点序列在NDV毒力中的作用。将无毒菌株LaSota F蛋白裂解位点的G-R-Q-G-R序列突变为神经毒性菌株Beaudette C (BC) F蛋白裂解位点的R-R-Q-K-R序列。由此产生的突变LaSota V.F.病毒在细胞培养中不需要外源蛋白酶来获得感染性，这表明F蛋白是由细胞内蛋白酶切割的。通过鸡脑内致病性指数（ICPI）和静脉内致病性指数（IVPI）试验，在体内评价突变病毒和亲本病毒的毒力。结果表明，对F蛋白切割位点进行修饰后，LaSota的ICPI值从0.00急剧增加到1.12，而LaSota vf的ICPI值低于BC的1.58。有趣的是，与BC的IVPI值1.45相比，LaSota和LaSota vf病毒的IVPI值均为0.00。并对病毒的体外特性进行了研究。我们的研究结果表明，如果NDV直接进入小鸡的大脑，F蛋白的切割效率起着重要作用，但可能还有其他病毒因素可能影响外周复制、病毒血症或进入中枢神经系统。
Newcastle disease virus (NDV) causes a highly contagious and economically important disease in poultry. Viral determinants of NDV virulence are not completely understood. The amino acid sequence at the protease cleavage site of the fusion (F) protein has been postulated as a major determinant of NDV virulence. In this study, we have examined the role of F protein cleavage site sequence in NDV virulence using reverse genetics technology. The sequence G-R-Q-G-R present at the cleavage site of the F protein of avirulent strain LaSota was mutated to R-R-Q-K-R, which is present in the F cleavage site of neurovirulent strain Beaudette C (BC). The resultant mutated LaSota V.F. virus did not require exogenous protease for infectivity in cell culture, indicating that the F protein was cleaved by intracellular proteases. The virulence of the mutant and parental viruses was evaluated in vivo by intracerebral pathogenicity index (ICPI) and intravenous pathogenicity index (IVPI) tests in chickens. Our results showed that the modification of the F protein cleavage site resulted in a dramatic increase in virulence from an ICPI value of 0.00 for LaSota to a value of 1.12 for LaSota V.F. However, the ICPI value of LaSota V.F. was lower than that of BC, which had a value of 1.58. Interestingly, the IVPI tests showed values of 0.00 for both LaSota and LaSota V.F. viruses, compared to the IVPI value of 1.45 of BC. In vitro characteristics of the viruses were also studied. Our results demonstrate that the efficiency of cleavage of the F protein plays an important role if the NDV is delivered directly into the brains of chicks, but there could be other viral factors that probably affect peripheral replication, viremia, or entry into the central nervous system.
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DOI：
10.1016/s1357-2725(01)00127-3
发表时间：
2002-04-01
影响因子：
4
作者：
Cobaleda, C;Muñoz-Barroso, I;Villar, E
通讯作者：
Villar, E
影响因子：
5.4
作者：
Duprex, WP;Duffy, I;Rima, BK
通讯作者：
Rima, BK
影响因子：
5.4
作者：
Heise, MT;Simpson, DA;Johnston, RE
通讯作者：
Johnston, RE
影响因子：
5.4
作者：
LYCKE, E;TSIANG, H
通讯作者：
TSIANG, H
影响因子：
3.8
作者：
Krishnamurthy, S;Samal, SK
通讯作者：
Samal, SK