Equine herpesvirus type 1 (EHV-1) causes encephalomyelopathy and abortion, for which cell-associated viremia and subsequent virus transfer to and replication in endothelial cells (EC) are responsible and prerequisites. Viral and cellular molecules responsible for efficient cell-to-cell spread of EHV-1 between peripheral blood mononuclear cells (PBMC) and EC remain unclear. We have generated EHV-1 mutants lacking ORF1, ORF2, and ORF17 genes, either individually or in combination. Mutant viruses were analyzed for their replication properties in cultured equine dermal cells, PBMC infection efficiency, virus-induced changes in the PBMC proteome, and cytokine and chemokine expression profiles. ORF1, ORF2, and ORF17 are not essential for virus replication, but ORF17 deletion resulted in a significant reduction in plaque size. Deletion of ORF2 and ORF17 gene significantly reduced cell-to-cell virus transfer from virus-infected PBMC to EC. EHV-1 infection of PBMC resulted in upregulation of several pathways such as Ras signaling, oxidative phosphorylation, platelet activation and leukocyte transendothelial migration. In contrast, chemokine signaling, RNA degradation and apoptotic pathways were downregulated. Deletion of ORF1, ORF2 and ORF17 modulated chemokine signaling and MAPK pathways in infected PBMC, which may explain the impairment of virus spread between PBMC and EC. The proteomic results were further confirmed by chemokine assays, which showed that virus infection dramatically reduced the cytokine/chemokine release in infected PBMC. This study uncovers cellular proteins and pathways influenced by EHV-1 after PBMC infection and provide an important resource for EHV-1 pathogenesis. EHV-1-immunomodulatory genes could be potential targets for the development of live attenuated vaccines or therapeutics against virus infection.

中文翻译：

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1型马疱疹病毒可调节单核细胞的细胞因子和趋化因子谱，以有效地传播至靶器官。

1型马疱疹病毒（EHV-1）引起脑脊髓病和流产，为此，与细胞相关的病毒血症以及随后的病毒转移和在内皮细胞（EC）中的复制是负责任的前提。尚不清楚导致EHV-1在外周血单核细胞（PBMC）和EC之间有效的细胞间传播的病毒和细胞分子。我们已经生成了缺少ORF1，ORF2和ORF17基因的EHV-1突变体，这些突变体单独或组合存在。分析突变病毒在培养的马真皮细胞中的复制特性，PBMC感染效率，PBMC蛋白质组中病毒诱导的变化以及细胞因子和趋化因子表达谱。ORF1，ORF2和ORF17对于病毒复制不是必需的，但是ORF17缺失导致噬菌斑大小显着减少。ORF2和ORF17基因的删除大大减少了从病毒感染的PBMC到EC的细胞间病毒转移。PBMC的EHV-1感染导致多种途径的上调，例如Ras信号传导，氧化磷酸化，血小板活化和白细胞跨内皮迁移。相反，趋化因子信号转导，RNA降解和凋亡途径被下调。删除ORF1，ORF2和ORF17在受感染的PBMC中调节趋化因子信号转导和MAPK途径，这可能解释了PBMC和EC之间病毒传播的损害。蛋白质组学结果通过趋化因子测定进一步证实，该结果表明病毒感染显着降低了感染的PBMC中的细胞因子/趋化因子释放。该研究揭示了PBMC感染后受EHV-1影响的细胞蛋白和途径，为EHV-1的发病机理提供了重要的资源。EHV-1-免疫调节基因可能是减毒活疫苗或抗病毒感染治疗剂开发的潜在目标。