Baigent Susan J, Petherbridge Lawrence J, Smith Lorraine P, Zhao Yuguang, Chesters Peter M, Nair Venugopal K
Institute for Animal Health, Compton Laboratory, Compton, Newbury, Berkshire RG20 7NN, UK.
J Gen Virol. 2006 Apr;87(Pt 4):769-776. doi: 10.1099/vir.0.81498-0.
Herpesvirus of turkey (HVT) is an alphaherpesvirus that is widely used as a live vaccine against Marek's disease because of its antigenic relationship with Marek's disease virus (MDV). In spite of a similar genome structure, HVT has several unique genes, the functions of which are not completely understood. As a first step in carrying out detailed analysis of the functions of the HVT genes, a full-length infectious bacterial artificial chromosome (BAC) clone of HVT was constructed. DNA from two independent BAC clones, upon transfection into chicken embryo fibroblasts, produced plaques similar to those produced by the wild-type virus. Viruses derived from the BAC clones were stable during in vitro passage, but showed differences in in vitro growth kinetics compared with the wild-type virus. Using a one-step mutagenesis protocol to delete the essential glycoprotein B gene from the HVT genome, followed by construction of the revertant virus, BAC clones of HVT were shown to be amenable to standard mutagenesis techniques. In spite of the difference in in vitro growth, viruses from both clones induced 100 % protection against infection by the virulent MDV strain RB-1B, indicating that the BAC-derived viruses could be used as vaccines with efficacies similar to that of the parental virus. The construction of HVT BAC is a major step in understanding the functions of HVT genes by exploiting the power of BAC technology. Furthermore, the availability of the BAC clones enables use of HVT as a vector for expressing foreign genes.
火鸡疱疹病毒（HVT）是一种α疱疹病毒，由于其与马立克氏病病毒（MDV）的抗原关系，被广泛用作预防马立克氏病的活疫苗。尽管基因组结构相似，但HVT有几个独特的基因，其功能尚未完全了解。作为对HVT基因功能进行详细分析的第一步，构建了HVT的全长感染性细菌人工染色体（BAC）克隆。来自两个独立BAC克隆的DNA转染鸡胚成纤维细胞后，产生的噬斑与野生型病毒产生的噬斑相似。源自BAC克隆的病毒在体外传代过程中是稳定的，但与野生型病毒相比，其体外生长动力学存在差异。使用一步诱变方案从HVT基因组中删除必需的糖蛋白B基因，随后构建回复病毒，结果表明HVT的BAC克隆适用于标准诱变技术。尽管体外生长存在差异，但两个克隆的病毒均能诱导对强毒MDV株RB-1B感染的100%保护，这表明BAC衍生的病毒可作为疫苗使用，其效力与亲本病毒相似。构建HVT BAC是利用BAC技术的力量来理解HVT基因功能的重要一步。此外，BAC克隆的可用性使得HVT能够用作表达外源基因的载体。
