Moore Ian N, Lamirande Elaine W, Paskel Myeisha, Donahue Danielle, Kenney Heather, Qin Jing, Subbarao Kanta
Laboratory of Infectious Diseases, NIAID, NIH, Bethesda, Maryland, USA.
Mouse Imaging Facility, NINDS, NIH, Bethesda, Maryland, USA.
J Virol. 2014 Dec;88(23):13879-91. doi: 10.1128/JVI.02341-14. Epub 2014 Sep 3.
Ferrets are a valuable model for influenza virus pathogenesis, virus transmission, and antiviral therapy studies. However, the contributions of the volume of inoculum administered and the ferret's respiratory tract anatomy to disease outcome have not been explored. We noted variations in clinical disease outcomes and the volume of inoculum administered and investigated these differences by administering two influenza viruses (A/California/07/2009 [H1N1 pandemic] and A/Minnesota/11/2010 [H3N2 variant]) to ferrets intranasally at a dose of 10(6) 50% tissue culture infective doses in a range of inoculum volumes (0.2, 0.5, or 1.0 ml) and followed viral replication, clinical disease, and pathology over 6 days. Clinical illness and respiratory tract pathology were the most severe and most consistent when the viruses were administered in a volume of 1.0 ml. Using a modified micro-computed tomography imaging method and examining gross specimens, we found that the right main-stem bronchus was consistently larger in diameter than the left main-stem bronchus, though the latter was longer and straighter. These anatomic features likely influence the distribution of the inoculum in the lower respiratory tract. A 1.0-ml volume of inoculum is optimal for delivery of virus to the lower respiratory tract of ferrets, particularly when evaluation of clinical disease is desired. Furthermore, we highlight important anatomical features of the ferret lung that influence the kinetics of viral replication, clinical disease severity, and lung pathology.
Ferrets are a valuable model for influenza virus pathogenesis, virus transmission, and antiviral therapy studies. Clinical disease in ferrets is an important parameter in evaluating the virulence of novel influenza viruses, and findings are extrapolated to virulence in humans. Therefore, it is highly desirable that the data from different laboratories be accurate and reproducible. We have found that, even when the same virus was administered at similar doses, different investigators reported a range of clinical disease outcomes, from asymptomatic infection to severe weight loss, ocular and nasal discharge, sneezing, and lethargy. We found that a wide range of inoculum volumes was used to experimentally infect ferrets, and we sought to determine whether the variations in disease outcome were the result of the volume of inoculum administered. These data highlight some less explored features of the model, methods of experimental infection, and clinical disease outcomes in a research setting.
雪貂是流感病毒发病机制、病毒传播及抗病毒治疗研究的重要模型。然而，接种物体积及雪貂呼吸道解剖结构对疾病结果的影响尚未得到探究。我们注意到临床疾病结果及接种物体积存在差异，并通过向雪貂鼻腔内接种两种流感病毒（A/加利福尼亚/07/2009 [H1N1大流行株] 和A/明尼苏达/11/2010 [H3N2变异株]）进行研究，接种剂量为10(6) 50%组织培养感染剂量，接种物体积范围为0.2、0.5或1.0毫升，随后在6天内跟踪病毒复制、临床疾病及病理学情况。当以1.0毫升的体积接种病毒时，临床疾病及呼吸道病理学表现最为严重且最为一致。使用改良的微型计算机断层扫描成像方法并检查大体标本，我们发现右主支气管直径始终大于左主支气管，尽管左主支气管更长且更直。这些解剖学特征可能影响接种物在下呼吸道的分布。1.0毫升的接种物体积最适合将病毒递送至雪貂的下呼吸道，尤其是在需要评估临床疾病时。此外，我们强调了雪貂肺部影响病毒复制动力学、临床疾病严重程度及肺部病理学的重要解剖学特征。
雪貂是流感病毒发病机制、病毒传播及抗病毒治疗研究的重要模型。雪貂的临床疾病是评估新型流感病毒毒力的重要参数，研究结果可外推至人类的毒力情况。因此，非常希望不同实验室的数据准确且可重复。我们发现，即使以相似剂量接种相同病毒，不同研究者报告的临床疾病结果也存在差异，从无症状感染到严重体重减轻、眼鼻分泌物、打喷嚏及嗜睡等情况都有。我们发现用于实验感染雪貂的接种物体积范围很广，我们试图确定疾病结果的差异是否是接种物体积所致。这些数据突出了该模型、实验感染方法及研究环境中临床疾病结果一些较少被探究的特征。
