Smith Jeffrey S, Xu Zhili, Tian Jie, Stevenson Susan C, Byrnes Andrew P
Division of Cellular and Gene Therapies, Food and Drug Administration Center for Biologics Evaluation and Research, Bethesda, MD 20892, USA.
Hum Gene Ther. 2008 May;19(5):547-54. doi: 10.1089/hum.2008.004.
When adenovirus (Ad) vectors are injected intravenously they are rapidly taken up by Kupffer cells (KCs) in the liver. This results in massive KC necrosis within minutes, followed by a more gradual disappearance of KCs from the liver. It is not known how KCs recognize Ad, or why Ad kills KCs. We used a variety of mutated and fiber-pseudotyped Ad vectors to evaluate how capsid proteins influence Ad uptake by KCs and to define the viral proteins that are involved in the destruction of KCs. We found that depletion of KCs from the liver was partially dependent on interactions between Ad and integrins, but was independent of the coxsackievirus and Ad receptor. The Ad5 fiber shaft was proven to be a particularly important contributory factor, because vectors with the shorter Ad35 shaft were not as effective at depleting KCs. In contrast, the fiber head played no discernible role. Variations in the ability of Ad vectors to deplete KCs could not be explained by differences in the amount of Ad that reached KCs, because all mutant Ads were accumulated by KCs at similar levels. Interestingly, we found that the Ad mutant ts1 did not cause KC death; this virus is known to bind and enter cells normally, but the capsid is unable to disassemble or lyse membranes. We conclude that Ad vectors kill KCs at a postbinding step and that this cell death can be mitigated if downstream events in viral entry are blocked.
当腺病毒（Ad）载体经静脉注射时，它们会迅速被肝脏中的库普弗细胞（KC）摄取。这会在数分钟内导致大量KC坏死，随后肝脏中的KC会逐渐消失。目前尚不清楚KC如何识别Ad，也不清楚Ad为何会杀死KC。我们使用了多种突变型和纤维假型Ad载体，以评估衣壳蛋白如何影响KC对Ad的摄取，并确定参与破坏KC的病毒蛋白。我们发现，肝脏中KC的耗竭部分依赖于Ad与整合素之间的相互作用，但与柯萨奇病毒和Ad受体无关。事实证明，Ad5纤维杆是一个特别重要的促成因素，因为具有较短Ad35杆的载体在耗尽KC方面效果不佳。相比之下，纤维头没有明显作用。Ad载体耗尽KC能力的差异无法用到达KC的Ad量的差异来解释，因为所有突变型Ad被KC积累的水平相似。有趣的是，我们发现Ad突变体ts1不会导致KC死亡；已知这种病毒能正常结合并进入细胞，但衣壳无法解体或裂解细胞膜。我们得出结论，Ad载体在结合后步骤杀死KC，如果病毒进入的下游事件被阻断，这种细胞死亡可以得到缓解。
