Avian infectious bronchitis virus enters cells via the endocytic pathway.
Avian infectious bronchitis virus enters cells via the endocytic pathway.
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DOI：
10.1007/978-0-387-33012-9_54
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发表时间：
2006
影响因子：
--
通讯作者：
Whittaker GR
中科院分区：
文献类型：
--
作者：
Chu VC;McElroy LJ;Ferguson AD;Bauman BE;Whittaker GR
禽传染性支气管炎病毒（IBV）是一种III组冠状病毒，对家禽业具有重大经济影响。受感染的蛋鸡通常由于卵巢和输卵管功能受损而导致产蛋量大幅下降。感染IBV的鸡的临床表现包括呼吸道、肾脏和生殖系统疾病，并且通常伴有继发性感染，如气囊炎和输卵管输卵管炎。[1]尽管自20世纪30年代以来，病因、发病机制和诊断方法就已被描述，但病毒进入的分子机制仍然难以捉摸。病毒利用各种机制进入其宿主细胞。包膜病毒需要脱落病毒包膜，以便将其基因组释放到靶细胞中并开始进一步复制。2去包被的过程通常遵循两种不同的机制：内体中的pH依赖性融合或细胞表面的pH非依赖性融合。许多包膜病毒（如流感病毒）利用各种内吞途径深入细胞质，以便顺利绕过细胞周边附近的皮质细胞骨架。4内吞途径还为pH依赖性膜融合提供合适的酸性环境，以将病毒基因组递送到细胞中。5，6相反，副粘病毒（例如仙台病毒）通过与质膜的pH非依赖性融合进入靶细胞。7对于冠状病毒，关于内体和低pH激活的作用，已经报道了对比结果，因此，关于进入机制没有普遍共识。8- 11 IBV感染的细胞的主要特征是形成大的合胞体，其已成为支持在病毒进入期间在中性pH下与细胞质膜融合的关键证据。[12]在该模型中，pH中性合胞体形成被认为是冠状病毒在进入过程中融合的代表性模型。然而，Patterson等人的电子显微镜清楚地显示IBV通过“病毒丛”通过细胞吞噬进入绒毛尿囊膜（CAM）和鸡肾细胞，
Avian infectious bronchitis virus (IBV) is a group III coronavirus that has a major economic impact in the poultry industry. Infected layers often have a large drop in egg production due to impaired ovary and oviduct functions. Clinical manifestations of IBV-infected chickens include respiratory, renal, and reproductive diseases and are often coupled with secondary infections such as airsaculitis and oviduct salpingitis. 1 Although the etiology, pathogenesis, and diagnosis have been described since the 1930s, the molecular mechanism of viral entry remains elusive. Viruses utilize various mechanisms to gain entry into their host cells. Enveloped viruses need to shed the viral envelope in order to release their genomes into target cells and initiate further replication. 2 The process of uncoating typically follows two distinct mechanisms: pH-dependent fusion in the endosome or pH-independent fusion at the cell surface. 3 Many enveloped viruses (eg, influenza viruses) utilize various endocytic pathways to travel deep into the cell cytoplasm in order to smoothly bypass the cortical cytoskeleton near the cell periphery. 4 The endocytic pathway also provides a suitable acidic environment for the pH-dependent membrane fusion to deliver the viral genome into the cell. 5, 6 In contrast, paramyxoviruses (eg, Sendai viruses) are well established to enter target cells via pH-independent fusion with the plasma membrane. 7 For coronaviruses, contrasting results have been reported regarding the role of endosomes and low pH activation, and consequently, there is no general consensus regarding the entry mechanism. 8-11A major characteristic of IBV infected cells is the formation of large syncytia, which has become a key piece of evidence supporting fusion with the cell plasma membrane at neutral pH during viral entry. 12 In this model, pH-neutral syncytia formation is thought to be a representative model of coronavirus fusion during entry. However, electron microscopy from Patterson et al. clearly shows IBV entering chorioallantoic membrane (CAM) and chick kidney cells via “viroplexis” through cellular engulfment into