Absence of host innate immune responses in SARS-CoV-infected ferrets upon subsequent challenge

To further investigate the underlying mechanisms of severe acute respiratory syndrome (SARS) pathogenesis and evaluate the therapeutic efficacy of potential drugs and vaccines it is necessary to use an animal model that is highly representative of the human condition in terms of respiratory anatomy, physiology and clinical sequelae. The ferret, Mustela putorius furo, supports SARS-CoV replication and displays many of the symptoms and pathological features seen in SARS-CoV-infected humans. We have recently established a SARS-CoV infection-challenge ferret platform for use in evaluating potential therapeutics to treat SARS. The main objective of the current study was to extend our previous results and identify early host immune responses upon infection and determine immune correlates of protection upon challenge with SARS-CoV in ferrets. Keywords: time course This study is a simple time course (58 day) examination of host responses in 35 SARS-CoV (TOR2) infected ferrets with the addition of a challenge inoculation of SARS CoV (TOR2) at day 29 post infection. Three mock-infected ferrets are included as negative controls. Due to the unavailability of ferret microarrays, Affymetrix Canine 2.0 oligonucleotide arrays were chosen following sequence analysis of our ferret cDNA library (~5000 clones) and demonstration of high levels of homology (>80%) between dog and ferret.为深入探究严重急性呼吸综合征（severe acute respiratory syndrome, SARS）的致病机制，并评估潜在药物与疫苗的治疗效果，亟需建立一种在呼吸系统解剖结构、生理特征及临床后遗症方面高度模拟人类疾病状态的动物模型。雪貂（Mustela putorius furo）可支持严重急性呼吸综合征冠状病毒（SARS-CoV）的复制，并呈现出SARS-CoV感染人类时的多数症状与病理特征。本团队近期已构建用于评估SARS潜在治疗手段的SARS-CoV感染-攻击雪貂模型平台。本研究的核心目标在于拓展前期研究成果，明确雪貂感染SARS-CoV后的早期宿主免疫应答，并解析攻击感染后宿主的免疫保护相关关联因素。 关键词：时间进程（time course） 本研究为一项为期58天的简单时间进程实验，对35只经SARS-CoV（TOR2株）感染的雪貂的宿主应答进行检测，并于感染后第29天对其进行SARS-CoV（TOR2株）攻击接种。同时设置3只模拟感染雪貂作为阴性对照。 由于暂无商用雪貂基因芯片，本研究通过对自建雪貂cDNA文库（约5000个克隆）进行序列分析，并验证犬与雪貂基因间存在>80%的同源性后，选用Affymetrix犬源2.0寡核苷酸芯片开展后续实验。