Increased pathogenicity of European porcine reproductive and respiratory syndrome virus is associated with enhanced adaptive responses and viral clearance
Increased pathogenicity of European porcine reproductive and respiratory syndrome virus is associated with enhanced adaptive responses and viral clearance
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DOI：
10.1016/j.vetmic.2012.11.024
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发表时间：
2013-04-12
影响因子：
3.3
通讯作者：
Frossard, J. P.
中科院分区：
文献类型：
--
作者：
Morgan, S. B.;Graham, S. P.;Frossard, J. P.
猪繁殖与呼吸综合征（PRRS）是全世界猪的经济上最重要的疾病之一。自 1987 年首次出现以来，PARS 病毒 (PRRSV) 已变得特别分化，在欧洲和亚洲都出现了高致病性毒株。然而，PRRSV发病机制的潜在机制仍不清楚。本研究旨在确定欧洲 PRRSV 1 亚型和 3 亚型毒株 (PRRSV-I) 之间发病机制的差异，并比较针对这些毒株的免疫反应。仔猪感染了 3 种 PRRSV-I 株：莱利斯塔德病毒、英国野外株 215-06 和白俄罗斯的 SU1-bel。在感染后 3 天和 7 天 (dpi) 进行尸检，每组中剩余一半的动物接种奥耶斯基氏病 (ADV) 疫苗，以调查 PRRSV 感染可能导致的免疫抑制。与 1 亚型菌株相比，3 亚型 SU1-bel 菌株表现出更强的临床症状和肺部大体病理学评分。这种差异似乎并不是由较高的病毒复制引起的，因为 SU1-bel 组中的病毒血症和支气管肺泡灌洗液 (BALF) 中的病毒载量较低。 SU1-bel感染诱导增强的适应性免疫反应，具有更强的干扰素(IFN)-γ反应和更早的PRRSV特异性抗体反应。 PRRSV 感染并不影响 ADV 疫苗接种的反应。我们的结果表明，SU1-bel毒株临床和病理效应的增加更可能是由炎症免疫反应增强而不是病毒复制水平升高引起的。皇冠版权所有 (C) 2012 由 Elsevier B.V. 出版。保留所有权利。
Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically important diseases of swine worldwide. Since its first emergence in 1987 the PARS virus (PRRSV) has become particularly divergent with highly pathogenic strains appearing in both Europe and Asia. However, the underlying mechanisms of PRRSV pathogenesis are still unclear. This study sets out to determine the differences in pathogenesis between subtype 1 and 3 strains of European PRRSV (PRRSV-I), and compare the immune responses mounted against these strains. Piglets were infected with 3 strains of PRRSV-I: Lelystad virus, 215-06 a British field strain and SU1-bel from Belarus. Post-mortem examinations were performed at 3 and 7 days post-infection (dpi), and half of the remaining animals in each group were inoculated with an Aujeszky's disease (ADV) vaccine to investigate possible immune suppression resulting from PRRSV infection. The subtype 3 SU1-bel strain displayed greater clinical signs and lung gross pathology scores compared with the subtype 1 strains. This difference did not appear to be caused by higher virus replication, as viraemia and viral load in broncho-alveolar lavage fluid (BALF) were lower in the SU1 -bel group. Infection with SU1 -bel induced an enhanced adaptive immune response with greater interferon (IFN)-gamma responses and an earlier PRRSV-specific antibody response. Infection with PRRSV did not affect the response to vaccination against ADV. Our results indicate that the increased clinical and pathological effect of the SU1 -bel strain is more likely to be caused by an enhanced inflammatory immune response rather than higher levels of virus replication. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.