Human herpesvirus-6A and-6B encode viral immunoevasins that downregulate class I MHC molecules
Human herpesvirus-6A and-6B encode viral immunoevasins that downregulate class I MHC molecules
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DOI：
10.1016/j.virol.2007.03.048
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发表时间：
2007-08-15
期刊：
影响因子：
3.7
通讯作者：
Hudson, Amy W.
中科院分区：
文献类型：
--
作者：
Glosson, Nicole L.;Hudson, Amy W.
与疱疹病毒家族的所有其他成员一样，密切相关的人类疱疹病毒-6和-7(HHV-6，7)终生存在于宿主体内。在这样做的过程中，无一例外，疱疹病毒家族的每个成员都进化出了避免被免疫系统检测的机制。特别是，人类巨细胞病毒(HCMV)、小鼠巨细胞病毒(MCMV)、人类疱疹病毒-8(HHV-8)和单纯疱疹病毒(HSV)都编码多种蛋白质，干扰正确的MHC I类抗原递呈。这些病毒从细胞表面去除MHC I类物质的机制各不相同。来自HHV-7的U21开放阅读框架通过一种未知的机制将I类MHC分子转移到内溶酶体隔室。HHV-6的两个变种HHV-6A和HHV-613都具有一个U21开放阅读框，其氨基酸序列与HHV-7的U21序列仅有30%的同源性。在这里，我们描述了HHV-6A和HHV-6B的U21基因产物的特征。像HHV-7U21一样，HHV-6U21分子都与I类MHC分子结合并转移到内溶酶体隔室，有效地将它们从细胞表面移除，并提供了一种可能的逃避免疫检测的方法。(C)2007 Elsevier Inc.保留所有权利。
Like all other members of the herpesvirus family, the closely related human herpesviruses-6 and -7 (HHV-6,7) persist in their host throughout life. In so doing, without exception, every member of the herpesvirus family has evolved mechanisms to avoid detection by the immune system. In particular, human cytomegalovirus (HCMV), mouse cytomegalovirus (MCMV), human herpesvirus-8 (HHV-8), and herpes simplex virus (HSV) all encode multiple proteins that interfere with proper MHC class I antigen presentation. The mechanisms employed by these viruses to effect removal of MHC class I from the cell surface vary. The U21 open reading frame from HHV-7 diverts class I MHC molecules to an endolysosomal compartment using an as-yet unknown mechanism. The two variants of HHV-6, HHV-6A and -613, both possess a U21 open reading frame which contain only similar to 30% amino acid identity to the U21 sequence from HHV-7. Here we describe the characterization of the U21 gene products from HHV-6A and HHV-6B. Like HHV-7 U21, both of the HHV-6 U21 molecules bind to and divert class I MHC molecules to an endolysosomal compartment, effectively removing them from the cell surface, and providing a possible means of escape from immune detection. (c) 2007 Elsevier Inc. All rights reserved.