Infectious Spleen and Kidney Necrosis Virus (a Fish Iridovirus) Enters Mandarin Fish Fry Cells via Caveola-Dependent Endocytosis
Infectious Spleen and Kidney Necrosis Virus (a Fish Iridovirus) Enters Mandarin Fish Fry Cells via Caveola-Dependent Endocytosis
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DOI：
10.1128/jvi.06947-11
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发表时间：
2012-03-01
影响因子：
5.4
通讯作者：
He, Jian-Guo
中科院分区：
文献类型：
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作者：
Guo, Chang-Jun;Wu, Yan-Yan;He, Jian-Guo
传染性脾肾坏死病毒（ISKNV）是虹彩病毒科巨细胞病毒属的模式种。巨细胞病毒与50多种鱼类感染有关，目前威胁着水产养殖业，给中国、日本和东南亚造成了巨大的经济损失。然而，巨细胞病毒的细胞进入机制在很大程度上仍然未知。本研究利用鳜鱼鱼苗（MFF-1）细胞研究了ISKNV的主要内化机制。 ISKNV 感染的进展缓慢，并且当用网格蛋白依赖性内吞作用抑制剂氯化铵 (NH4Cl)、氯喹、蔗糖和氯丙嗪处理细胞时，感染不会受到抑制。甲基-β-环糊精消耗细胞胆固醇可显着抑制 ISKNV 感染；然而，补充胆固醇后感染又会恢复。 Caveolin-L 相关信号传导事件的抑制剂，包括佛波醇 12-肉豆蔻酸酯 13-乙酸酯 (PMA)、金雀异黄酮和渥曼青霉素，会损害 ISKNV 进入 MFF-1 细胞。此外，ISKNV 的进入依赖于动力和微管细胞骨架。 ISKNV 和 Caveolin-1 的共分数分析表明，ISKNV 在病毒感染过程中与 Caveolin-1 共存。这些结果表明，ISKNV 进入 MFF-1 细胞是通过经典的小窝介导的内吞作用进行的，并且依赖于微管，微管充当运动小泡可通过小窝-小泡体-内质网 (ER) 途径移动的轨道。作为鱼类虹彩病毒，ISKNV进入MFF-1细胞与青蛙病毒3号在28℃进入哺乳动物细胞（BHK-21）的网格蛋白介导的内吞作用不同，后者已被公认为虹彩病毒的模型。因此，我们的工作可能有助于进一步了解虹彩病毒感染的初始步骤。
Infectious spleen and kidney necrosis virus (ISKNV) is the type species of the genus Megalocytivirus from the family Iridoviridae. Megalocytiviruses have been implicated in more than 50 fish species infections and currently threaten the aquaculture industry, causing great economic losses in China, Japan, and Southeast Asia. However, the cellular entry mechanisms of megalocytiviruses remain largely uncharacterized. In this study, the main internalization mechanism of ISKNV was investigated by using mandarin fish fry (MFF-1) cells. The progression of ISKNV infection is slow, and infection is not inhibited when the cells are treated with ammonium chloride (NH4Cl), chloroquine, sucrose, and chlorpromazine, which are inhibitors of clathrin-dependent endocytosis. The depletion of cellular cholesterol by methyl-beta-cyclodextrin results in the significant inhibition of ISKNV infection; however, the infection is resumed with cholesterol replenishment. Inhibitors of caveolin-l-involved signaling events, including phorbol 12-myristate 13-acetate (PMA), genistein, and wortmannin, impair ISKNV entry into MFF-1 cells. Moreover, ISKNV entry is dependent on dynamin and the microtubule cytoskeleton. Cofraction analysis of ISKNV and caveolin-1 showed that ISKNV colocates with caveolin-1 during virus infection. These results indicate that ISKNV entry into MFF-1 cells proceeds via classical caveola-mediated endocytosis and is dependent on the microtubules that serve as tracks along which motile cavicles may move via a caveola-caveosome-endoplasmic reticulum (ER) pathway. As a fish iridovirus, ISKNV entry into MFF-1 cells is different from the clathrin-mediated endocytosis of frog virus 3 entry into mammalian cells (BHK-21) at 28 degrees C, which has been recognized as a model for iridoviruses. Thus, our work may help further the understanding of the initial steps of iridovirus infection.