Current knowledge on the structural proteins of porcine reproductive and respiratory syndrome (PRRS) virus: comparison of the North American and European isolates.
Current knowledge on the structural proteins of porcine reproductive and respiratory syndrome (PRRS) virus: comparison of the North American and European isolates.
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DOI：
10.1007/s007050050662
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发表时间：
2000
影响因子：
2.7
通讯作者：
Rogan D
中科院分区：
文献类型：
--
作者：
Dea S;Gagnon CA;Mardassi H;Pirzadeh B;Rogan D
猪繁殖与呼吸综合征病毒（Porcine reproductive and respiratory syndrome virus，PRRSV）属于最近认识到的动脉炎病毒科（Arteriviridae）动脉炎病毒属（Arterivirus），巢状病毒目（Nidovirales），其还包括马动脉炎病毒（EAV）、乳酸脱氢酶升高病毒（LDV）和猿猴出血热病毒（SHFV）。成熟病毒颗粒由直径为50-72 nm的包膜和约20-30 nm的等轴核心组成，其中包含约15 kb的线性正链RNA基因组。病毒体通过预先形成的核衣壳出芽到滑面内质网和/或高尔基体的内腔中而组装。成熟的病毒体然后通过胞吐作用释放。病毒基因组包含八个开放阅读框（ORF），其在细胞中转录为亚基因组mRNA的嵌套集合。ORF 1a和ORF 1b位于基因组的5′端，占病毒基因组的近75%，编码具有明显复制酶和聚合酶活性的蛋白。主要结构蛋白包括25 kDa的包膜糖蛋白（GP 5）、18-19 kDa的非糖基化膜蛋白（M）和15 kDa的核衣壳（N）蛋白，分别由ORF 5、6和7编码。N蛋白是病毒粒子中更丰富的蛋白，并且具有高度抗原性，因此使其成为检测病毒特异性抗体和诊断疾病的合适候选物。已经鉴定了N蛋白的四到五个抗原重要性结构域，这是欧洲和北美菌株的共同构象抗原位点，位于蛋白质的中心区域。在细胞和病毒体中，M和GP 5都以通过二硫键连接的异二聚体复合物的形式存在。ORF 2和4的表达产物也作为额外的次要膜相关糖蛋白掺入病毒颗粒中，称为GP 2和GP 4，其Mr分别为29和31 kDa。ORF 3产物是一种表观Mr为42 kDa的高度糖基化蛋白，鉴于其在病毒颗粒中存在的明显相互矛盾的数据，其结构性质仍在争论中。尽管如此，北美和欧洲毒株的GP 3已被证明是抗原性的，在没有明显的中和体液应答的情况下为仔猪提供针对PRRSV感染的保护。通过DNA免疫暴露于GP 5天然形式的猪产生特异性中和和保护抗体。GP 5参与抗原变异性、细胞凋亡和可能的抗体依赖性增强现象。GP 4还具有触发免疫系统产生中和抗体的抗原决定簇。每种PRRSV结构蛋白都携带共同的和类型特异性的抗原决定簇，从而能够区分欧洲和北美毒株。本文还讨论了PRRSV结构蛋白在亚单位重组型疫苗中的潜在应用。
Porcine reproductive and respiratory syndrome virus (PRRSV) belongs to the recently recognized Arteriviridae family within the genus Arterivirus, order Nidovirales, which also includes equine arteritis virus (EAV), lactate dehydrogenase-elevating virus (LDV), and simian hemorrhagic fever virus (SHFV). Mature viral particles are composed of an envelope 50–72 nm in diameter, with an isometric core about 20–30 nm enclosing a linear positive-stranded RNA genome of approximately 15 kb. The virions are assembled by the budding of preformed nucleocapsids into the lumen of the smooth endoplasmic reticulum and/or Golgi apparatus. The mature virions are then released by exocytosis. The viral genome contains eight open reading frames (ORFs) which are transcribed in cells as a nested set of subgenomic mRNAs. The ORF1a and ORF1b situated at the 5′end of the genome represent nearly 75% of the viral genome and code for proteins with apparent replicase and polymerase activities. The major structural proteins consist of a 25 kDa envelope glycoprotein (GP5), an 18–19 kDa unglycosylated membrane protein (M), and a 15 kDa nucleocapsid (N) protein, encoded by ORFs 5, 6 and 7, respectively. The N protein is the more abundant protein of the virion and is highly antigenic, which therefore makes it a suitable candidate for the detection of virus-specific antibodies and diagnosis of the disease. Four to five domains of antigenic importance have been identified for the N protein, a common conformational antigenic site for European and North American strains being localized in the central region of the protein. In cells and virions, both M and GP5 occur in heterodimeric complexes linked by disulfide bonds. The expression products of ORFs 2 and 4 are also incorporated into virus particles as additional minor membrane-associated glycoproteins designated as GP2 and GP4, with Mr of 29 and 31 kDa, respectively. The structural nature of the ORF3 product, a highly glycosylated protein with an apparent Mr of 42 kDa, is still being debated, in view of the apparently conflicting data on its presence in virus particles. Nonetheless, the GP3 of North American and European strains has been shown to be antigenic, providing protection for piglets against PRRSV infection in the absence of a noticeable neutralizing humoral response. Pigs exposed to the native form of GP5 by means of DNA immunization develop specific neutralizing and protecting antibodies. The GP5 is involved in antigenic variability, apoptosis, and possibly antibody-dependent enhancement phenomena. The GP4 also possesses antigenic determinants that trigger the immune system to produce neutralizing antibodies. Each of the PRRSV structural proteins carries common and type-specific antigenic determinants that permit the ability to differentiate between European and North American strains. The potential use of the PRRSV structural proteins in subunit recombinant-type vaccines is also discussed.
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影响因子：
1.5
作者：
BENFIELD, DA;NELSON, E;CHLADEK, D
通讯作者：
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影响因子：
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影响因子：
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作者：
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通讯作者：
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影响因子：
1.5
作者：
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