A NOVEL VARIANT OF AVIAN INFECTIOUS-BRONCHITIS VIRUS RESULTING FROM RECOMBINATION AMONG 3 DIFFERENT STRAINS
A NOVEL VARIANT OF AVIAN INFECTIOUS-BRONCHITIS VIRUS RESULTING FROM RECOMBINATION AMONG 3 DIFFERENT STRAINS
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DOI：
10.1007/bf01309861
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发表时间：
1995-01-01
影响因子：
2.7
通讯作者：
NAQI, SA
中科院分区：
文献类型：
--
作者：
JIA, W;KARACA, K;NAQI, SA
分离并鉴定了禽传染性支气管炎病毒（IBV）（一种冠状病毒）的抗原变体。这种菌株 CU-T2 具有许多不寻常的特征，这些特征以前从未在 IBV 中观察到过。 CU-T2 的 S1 糖蛋白携带阿肯色州 (Ark) 和马萨诸塞州 (Mass) 两种 IBV 血清型的病毒中和和血清型特异性表位。序列分析显示，该病毒最初是 Ark 血清型，通过突变获得了 Mass 特异性表位。这提供了证据，表明点突变可能导致现场产生 IBV 抗原变异体。进一步观察到，CU-T2的S2糖蛋白基因和N蛋白基因中发生了涉及三种不同IBV毒株的两次独立的重组事件，表明IBV的基因组RNA重组可能在自然界的多个基因中发生。尤其重要的是，Holland 52（疫苗株）的序列取代了CU-T2的一半N基因。这证明疫苗株之间的重组有助于在现场产生 IBV 变种。根据这些观察结果，预测每种 IBV 野外分离株都可能具有独特的遗传性质。因此，最近报道的几种基于斑点杂交、限制性片段长度多态性（RFLP）和聚合酶链式反应（PCR）的IBV诊断和血清分型方法可能无法揭示IBV分离株的真实抗原和/或遗传性质，并且实际上可能产生误导性信息。
An antigenic variant of avian infectious bronchitis virus (IBV), a coronavirus, was isolated and characterized. This strain, CU-T2, possesses a number of unusual features, which have not been previously observed in IBV. The S1 glycoprotein of CU-T2 carries virus-neutralizing and serotype-specific epitopes of two IBV serotypes, Arkansas (Ark) and Massachusetts (Mass). Sequence analysis revealed that the virus, originally an Ark serotype, has acquired the Mass-specific epitope by mutation(s). This provides evidence that point mutations may lead to generation of IBV antigenic variants in the field. It was further observed that two independent recombination events involving three different IBV strains had occurred in the S2 glycoprotein gene and N protein gene of CU-T2, indicating that genomic RNA recombination in IBV may occur in multiple genes in nature. It was especially significant that a sequence of Holland 52 (a vaccine strain) had replaced half of the N gene of CU-T2. This proves that recombination among vaccine strains is contributing to the generation of IBV variants in the field. Based on these observations it is predicted that every IBV field isolate could have unique genetic nature. Therefore, several recently reported diagnostic and serotyping methods of IBV which are based on dot-blot hybridization, restriction fragment length polymorphism (RFLP), and polymerase chain reaction (PCR), may not reveal the true antigenic and/or genetic nature of IBV isolates, and may in fact yield misleading information.