Ovine herpesvirus 2 replicates initially in the lung of experimentally infected sheep
Ovine herpesvirus 2 replicates initially in the lung of experimentally infected sheep
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DOI：
10.1099/vir.0.2008/000554-0
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发表时间：
2008-07-01
影响因子：
3.8
通讯作者：
Taus, Naomi S.
中科院分区：
文献类型：
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作者：
Li, Hong;Cunha, Cristina W.;Taus, Naomi S.
绵羊疱疹病毒2型（OvHV-2）是γ疱疹病毒亚科的一种鼻病毒，是引起绵羊相关恶性卡他热（SA-MCF）的病原体。由于不能在体外繁殖病毒，因此很难研究OvHV-2的复制。从自然感染绵羊的鼻分泌物中收集OvHV-2的羊在脱落事件的结果在幼稚羊的感染，提供了一个很好的系统，研究OvHV-2在自然宿主中的初始复制的气雾剂接种绵羊。在这项研究中，我们表明，OvHV-2通过鼻途径雾化导致感染的所有羔羊，但没有感染建立在任何羔羊静脉或腹腔注射后。在雾化的羔羊中，虽然最初在任何其他组织中未检测到OvHV-2 DNA，但在感染后3天（p.i.），在感染后5天增加到约900个拷贝/50 ng DNA，注射后7天达到峰值水平（类似于7500份），然后在感染后9天下降到平均800份。OvHV-2开放阅读框25（编码衣壳蛋白）的转录物（病毒复制的指标）仅在肺组织中检测到，并且与肺中的OvHV-2 DNA水平呈正相关。此外，所选免疫应答基因在感染后5天和7天也在肺中高度表达。这些数据表明，肺是OvHV-2在绵羊初始感染过程中的主要复制位点，并表明病毒复制迅速受到宿主防御机制的控制。
Ovine herpesvirus 2 (OvHV-2), a rhadinovirus in the subfamily Gammaherpesvirinae, is the causative agent of sheep-associated malignant catarrhal fever (SA-MCF), a frequently fatal lymphoproliferative disease primarily of ruminants worldwide. Inability to propagate the virus in vitro has made it difficult to study OvHV-2 replication. Aerosol inoculation of sheep with OvHV-2 from nasal secretions collected from naturally infected sheep during shedding episodes results in infection of naive sheep, providing an excellent system to study OvHV-2 initial replication in the natural host. In this study, we showed that OvHV-2 delivered through the nasal route by nebulization resulted in infection in all lambs, but no infection was established in any lambs after intravenous or intraperitoneal injection. In nebulized lambs, while it was not detected initially in any other tissues, OvHV-2 DNA became detectable in the lung at 3 days post-infection (p.i.), increased to about 900 copies per 50 ng DNA at 5 days p.i., reached peak levels (similar to 7500 copies) at 7 days p.i., and then declined to an average of 800 copies at 9 days p.i. Transcripts of OvHV-2 open reading frame 25 (coding for the capsid protein), an indicator of virus replication, were only detected in lung tissues, and were positively correlated with OvHV-2 DNA levels in the lungs. In addition, selected immune response genes were also highly expressed in the lung at 5 and 7 days p.i. The data indicate that lung is the primary replication site for OvHV-2 during initial infection in sheep and suggest that viral replication is promptly controlled by a host defence mechanism.