Liu Guangliang, Kahan Shannon M, Jia Yali, Karst Stephanie M
Center for Molecular and Tumor Virology, Department of Microbiology and Immunology, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130-3932, USA.
J Virol. 2009 Jul;83(13):6963-8. doi: 10.1128/JVI.00284-09. Epub 2009 Apr 29.
Human noroviruses in the Caliciviridae family are the major cause of nonbacterial epidemic gastroenteritis worldwide. Primary human norovirus infection does not elicit lasting protective immunity, a fact that could greatly affect the efficacy of vaccination strategies. Little is known regarding the pathogenesis of human noroviruses or the immune responses that control them because there has previously been no small-animal model or cell culture system of infection. Using the only available small-animal model of norovirus infection, we found that primary high-dose murine norovirus 1 (MNV-1) infection fails to afford protection against a rechallenge with a homologous virus. Thus, MNV-1 represents a valuable model with which to dissect the pathophysiological basis for the lack of lasting protection against human norovirus infection. Interestingly, the magnitude of protection afforded by a primary MNV-1 infection inversely correlates with the inoculum dose. Future studies will elucidate the mechanisms by which noroviruses avoid the induction of protective immunity and the role played by the inoculum dose in this process, ultimately translating this knowledge into successful vaccination approaches.
杯状病毒科的人类诺如病毒是全球非细菌性流行性肠胃炎的主要病因。原发性人类诺如病毒感染不会引发持久的保护性免疫，这一事实可能会极大地影响疫苗接种策略的效果。由于此前没有小动物感染模型或细胞培养系统，人们对人类诺如病毒的发病机制或控制它们的免疫反应知之甚少。利用唯一可用的诺如病毒感染小动物模型，我们发现原发性高剂量鼠诺如病毒1（MNV-1）感染无法提供针对同源病毒再次攻击的保护。因此，MNV-1是一个有价值的模型，可用于剖析缺乏针对人类诺如病毒感染的持久保护的病理生理基础。有趣的是，原发性MNV-1感染提供的保护程度与接种剂量呈负相关。未来的研究将阐明诺如病毒避免诱导保护性免疫的机制以及接种剂量在此过程中所起的作用，最终将这些知识转化为成功的疫苗接种方法。
