Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 300 West Drake Road, Fort Collins, CO 80523, USA.
Vet Microbiol. 2011 Apr 21;149(1-2):40-7. doi: 10.1016/j.vetmic.2010.10.004. Epub 2010 Oct 28.
Infection with equine herpesvirus-1 (EHV-1) causes respiratory disease, late term abortions and equine herpesvirus myeloencephalitis (EHM) and remains an important problem in horses worldwide. Despite increasing outbreaks of EHM in recent years, our understanding of EHM pathogenesis is still limited except for the knowledge that a cell-associated viremia in peripheral blood mononuclear cells (PBMCs) is a critical link between primary respiratory EHV-1 infection and secondary complications such as late-term abortion or EHM. To address this question our objective was to identify which PBMC subpopulation(s) are infected during viremia and may therefore play a role in transmitting the virus to the vascular endothelium of the spinal cord or pregnant uterus. PBMCs from 3 groups of animals were collected between days 4 and 9 following experimental infection with EHV-1 strain Findlay/OH03 or strain Ab4. PBMCs were labeled with primary antibodies selective for CD4+ or CD8+ T lymphocytes, B-lymphocytes, or monocytes and positively selected using magnetic bead separation. Cell numbers and EHV-1 genome numbers in each subpopulation were then determined using quantitative PCR for β-actin and the EHV-1 glycoprotein B, respectively. Viral genomic DNA was found in all PBMC subpopulations; the CD8+ lymphocytes were most frequently positive for viral DNA, followed by B-lymphocytes. These differences were statistically significant in horses infected with the EHV-1 strain Findlay/OH03, and ponies with Ab4. These results differ from what has been reported in in vitro studies, and indicate that different PBMC subpopulations may play different roles in EHV-1 viremia.
马疱疹病毒-1（EHV-1）感染可引起呼吸道疾病、晚期流产和马疱疹病毒脑脊髓炎（EHM），仍是全球马匹的重要问题。尽管近年来 EHM 的爆发越来越多，但除了知道外周血单核细胞（PBMC）中的细胞相关病毒血症是原发性呼吸道 EHV-1 感染与晚期流产或 EHM 等继发性并发症之间的关键环节之外，我们对 EHM 发病机制的了解仍然有限。为了解决这个问题，我们的目标是确定在病毒血症期间感染的 PBMC 亚群（多个），并可能因此在将病毒传播到脊髓或妊娠子宫的血管内皮细胞中发挥作用。在实验性感染 EHV-1 菌株 Findlay/OH03 或菌株 Ab4 后 4 至 9 天，从 3 组动物中收集 PBMC。使用针对 CD4+或 CD8+T 淋巴细胞、B 淋巴细胞或单核细胞的特异性的初级抗体标记 PBMC，并使用磁珠分离进行阳性选择。然后使用定量 PCR 分别针对β-肌动蛋白和 EHV-1 糖蛋白 B 确定每个亚群中的细胞数量和 EHV-1 基因组数量。在感染 EHV-1 菌株 Findlay/OH03 的马和 Ab4 的小马中，发现所有 PBMC 亚群中都存在病毒基因组 DNA；CD8+淋巴细胞最常对病毒 DNA 呈阳性，其次是 B 淋巴细胞。这些差异在感染 EHV-1 菌株 Findlay/OH03 的马和 Ab4 的小马中具有统计学意义。这些结果与体外研究报告的结果不同，表明不同的 PBMC 亚群在 EHV-1 病毒血症中可能发挥不同的作用。
