pH-independent entry and sequential endosomal sorting are major determinants of hepadnaviral infection in primary hepatocytes
pH-independent entry and sequential endosomal sorting are major determinants of hepadnaviral infection in primary hepatocytes
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DOI：
10.1002/hep.21297
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发表时间：
2006-09-01
期刊：
影响因子：
13.5
通讯作者：
Sirma, Hueseyin
中科院分区：
文献类型：
--
作者：
Funk, Anneke;Mhamdi, Mouna;Sirma, Hueseyin
B型肝炎病毒的进入和细胞内转运有几个不寻常的，很大程度上未知的方面。本研究利用鸭B肝炎病毒（DHBV）感染原代肝细胞模型，探讨病毒进入肝细胞的方式。内化后，病毒颗粒富集在内体区室中，如生化和超微结构分析所示。含病毒囊泡具有早期核内体标记。动力学分析表明，时间依赖性的部分易位的病毒DNA从内体进入胞质溶胶。这通过用巴弗洛霉素A1抑制液泡ATP酶（vATP酶）活性而强烈降低，并导致感染失败和cccDNA形成的预防。vATP酶的失活诱导进入的病毒颗粒在内体中的积累和稳定，推测是通过阻断内体载体囊泡介导的货物运输和分选。虽然单独中和内膜细胞器可以稳定传入的病毒颗粒，但不能抑制病毒感染。与此一致，不能人工诱导质膜上的pH依赖性异位病毒融合。这为pH中性易位机制提供了进一步的证据。内体膜电位所需的病毒感染，因为共同治疗的细胞与莫能菌素部分克服了巴弗洛霉素A1的抑制作用。总之，B型肝炎病毒感染是由一种新的细胞进入机制介导的，其特征不同于所有其他已知病毒。本文的补充材料可以在肝脏学网站上找到（http.// interscience.wiley.com/jpages/0270-9139/suppmat/index.html).
Entry and intracellular transport of hepatitis B viruses have several unusual, largely unknown aspects. In this study, we explored the mode of virus entry using the duck hepatitis B virus (DHBV) and the primary hepatocyte infection model. Upon internalization, viral particles were enriched in an endosomal compartment, as revealed by biochemical and ultrastructural analysis. Virus-containing vesicles harbored early endosome markers. Kinetic analysis revealed time-dependent partial translocation of viral DNA from endosomes into the cytosol. This was strongly reduced by inhibition of vacuolar ATPase; (vATPase) activity with bafilomycin A1 and resulted in abortive infection and prevention of cccDNA formation. Inactivation of vATPase induced accumulation and stabilization of incoming viral particles in endosomes, presumably by blocking endosomal carrier vesicle-mediated cargo transport and sorting. Although neutralization of the endomembrane organelles alone led to stabilization of incoming viral particles, it did not inhibit virus infection. In line with this, a pH-dependent ectopic virus fusion at the plasma membrane could not be artificially induced. This provided further evidence for a pH-neutral translocation mechanism. Endosomal membrane potential was required for viral infection because cotreatment of cells with monensin partially overcame the inhibitory effect of bafilomycin A1. In conclusion, hepatitis B viral infection is mediated by a novel cellular entry mechanism with features different from that of all other known viruses. Supplementary material for this article can be found on the HEPATOLOGY website (http.//interscience.wiley.com/jpages/0270-9139/suppmat/index.html).