HCMV Induces Macropinocytosis for Host Cell Entry in Fibroblasts
HCMV Induces Macropinocytosis for Host Cell Entry in Fibroblasts
复制标题
DOI：
10.1111/tra.12355
复制
发表时间：
2016-04-01
期刊：
影响因子：
4.5
通讯作者：
Krzyzaniak, Magdalena Anna
中科院分区：
文献类型：
--
作者：
Hetzenecker, Stefanie;Helenius, Ari;Krzyzaniak, Magdalena Anna
人巨细胞病毒（HCMV）是广泛存在于人群中的重要病原体。虽然这种-疱疹病毒在内皮细胞、上皮细胞和树突状细胞中的感染依赖于内吞作用，但它进入成纤维细胞被认为是通过病毒包膜与质膜的直接融合发生的。为了描述原代人成纤维细胞进入的各个步骤，我们采用了定量分析以及电子、荧光和活细胞显微镜，并结合了各种抑制化合物。我们的研究结果表明，虽然感染侵入与pH和网格蛋白无关，但它需要多种与内吞相关的因素和过程。发现病毒粒子迅速内化到含有内化液体和内核体标记物的大液泡中。内化过程的特征符合巨红细胞增多症的主要标准。此外，我们发现，在加入成纤维细胞后不久，病毒迅速触发宿主细胞中圆形背褶的形成，随后产生大的巨红细胞液泡。这种特殊形式的巨噬细胞增多症已被观察到，特别是在原代细胞中，但以前没有报道过对病毒刺激的反应。
Human cytomegalovirus (HCMV) is an important and widespread pathogen in the human population. While infection by this -herpesvirus in endothelial, epithelial and dendritic cells depends on endocytosis, its entry into fibroblasts is thought to occur by direct fusion of the viral envelope with the plasma membrane. To characterize individual steps during entry in primary human fibroblasts, we employed quantitative assays as well as electron, fluorescence and live cell microscopy in combination with a variety of inhibitory compounds. Our results showed that while infectious entry was pH- and clathrin-independent, it required multiple, endocytosis-related factors and processes. The virions were found to undergo rapid internalization into large vacuoles containing internalized fluid and endosome markers. The characteristics of the internalization process fulfilled major criteria for macropinocytosis. Moreover, we found that soon after addition to fibroblasts the virus rapidly triggered the formation of circular dorsal ruffles in the host cell followed by the generation of large macropinocytic vacuoles. This distinctive form of macropinocytosis has been observed especially in primary cells but has not previously been reported in response to virus stimulation.