Back Helena, Ullman Karin, Leijon Mikael, Söderlund Robert, Penell Johanna, Ståhl Karl, Pringle John, Valarcher Jean-François
Department of Virology, Immunobiology and Parasitology, National Veterinary Institute, Uppsala, Sweden.
Department of Bacteriology, National Veterinary Institute, Uppsala, Sweden.
J Gen Virol. 2016 Jan;97(1):169-178. doi: 10.1099/jgv.0.000332. Epub 2015 Oct 30.
Equid herpesvirus 5 (EHV-5) is related to the human Epstein-Barr virus (human herpesvirus 4) and has frequently been observed in equine populations worldwide. EHV-5 was previously assumed to be low to non-pathogenic; however, studies have also related the virus to the severe lung disease equine multinodular pulmonary fibrosis (EMPF). Genetic information of EHV-5 is scanty: the whole genome was recently described and only limited nucleotide sequences are available. In this study, samples were taken twice 1 year apart from eight healthy horses at the same professional training yard and samples from a ninth horse that was diagnosed with EMPF with samples taken pre- and post-mortem to analyse partial glycoprotein B (gB) gene of EHV-5 by using next-generation sequencing. The analysis resulted in 27 partial gB gene sequences, 11 unique sequence types and five amino acid sequences. These sequences could be classified within four genotypes (I-IV) of the EHV-5 gB gene based on the degree of similarity of the nucleotide and amino acid sequences, and in this work horses were shown to be identified with up to three different genotypes simultaneously. The observations showed a range of interactions between EHV-5 and the host over time, where the same virus persists in some horses, whereas others have a more dynamic infection pattern including strains from different genotypes. This study provides insight into the genetic variation and dynamics of EHV-5, and highlights that further work is needed to understand the EHV-5 interaction with its host.
马疱疹病毒5型（EHV-5）与人类爱泼斯坦-巴尔病毒（人类疱疹病毒4型）相关，在世界各地的马群中经常被发现。EHV-5以前被认为致病性较低或无致病性；然而，研究也将该病毒与严重的肺部疾病——马多结节性肺纤维化（EMPF）联系起来。EHV-5的遗传信息很少：其全基因组最近才被描述，仅有有限的核苷酸序列可用。在本研究中，从同一专业训练场的八匹健康马身上相隔1年采集两次样本，并从一匹被诊断患有EMPF的第九匹马身上在生前和死后采集样本，通过新一代测序分析EHV-5的部分糖蛋白B（gB）基因。分析产生了27个部分gB基因序列、11种独特的序列类型和5种氨基酸序列。根据核苷酸和氨基酸序列的相似程度，这些序列可分为EHV-5 gB基因的四种基因型（I-IV），并且在这项研究中发现马匹可同时被鉴定出多达三种不同的基因型。观察结果显示了EHV-5与宿主之间随时间变化的一系列相互作用，其中相同的病毒在一些马体内持续存在，而其他马则具有更动态的感染模式，包括来自不同基因型的毒株。本研究深入了解了EHV-5的遗传变异和动态变化，并强调需要进一步开展工作以了解EHV-5与其宿主的相互作用。
