Functional Analysis of Human Cytomegalovirus UL/b′ Region Using SCID-hu Mouse Model
Functional Analysis of Human Cytomegalovirus UL/b′ Region Using SCID-hu Mouse Model
复制标题
DOI：
10.1002/jmv.24484
复制
发表时间：
2016-08-01
影响因子：
12.7
通讯作者：
Zhu, Hua
中科院分区：
文献类型：
--
作者：
Dulal, Kalpana;Cheng, Tong;Zhu, Hua
人巨细胞病毒（HCMV）减毒株Towne和AD 169与原型致病性毒株如Toledo的不同之处在于它们在UL/B '区缺失了类似于15-kb的片段。与减毒株相反，Toledo可以在SCID（SCID-hu）小鼠的人体组织植入物中复制。因此，该模型为研究病毒致病机制提供了一个独特的体内系统。在UL/B '区域中已经注释了22个ORF，包括在五聚体gH/gl复合物中编码的组织嗜性基因。为了区分五聚体gH/gl复合物与15-kb区域中其他ORF在支持病毒体内生长中的功能的作用，构建了一系列重组病毒株，并测试了它们在SCID-hu小鼠中复制的能力。修复Towne和AD 169菌株中的突变以恢复其五聚体gH/gl复合物，并且发现这些变化并不能挽救它们在SCID-hu小鼠中的复制能力。随后，在来自Toledo株的15-kb区域中产生四种缺失病毒（D1、D2、D3和D4）。结果表明，D2和D3能够在SCID-hu小鼠中生长，而D1和D4不能存活。有趣的是，植入物与D1和D4病毒的共感染可以补偿它们各自的体内生长缺陷。结果表明，拯救病毒的上皮嗜性不足以逆转AD169或Towne的减毒表型，致病基因位于D1和D4病毒缺失的片段中。(C)2016 Wiley Periodicals，Inc.
Human cytomegalovirus (HCMV) attenuated strains, Towne, and AD169, differ from prototypic pathogenic strains, such as Toledo, in that they are missing a similar to 15-kb segment in the UL/b' region. In contrast to the attenuated strains, Toledo can replicate in human tissue implants in SCID (SCID-hu) mice. Thus, this model provides a unique in vivo system to study the mechanism of viral pathogenesis. Twenty-two ORFs have been annotated in the UL/b' region, including tissue-tropic genes encoded in a pentameric gH/gl complex. To differentiate the role of the pentameric gH/gl complex versus the functions of other ORFs in the 15-kb region in supporting viral growth in vivo, a series of recombinant viral strains were constructed and their ability to replicate in SCID-hu mice was tested. The mutations in the Towne and AD169 strains were repaired to restore their pentameric gH/gl complex and it was found that these changes did not rescue their inability to replicate in the SCID-hu mice. Subsequently four deletion viruses (D1, D2, D3, and D4) in the 15-kb region from the Toledo strain were created. It was demonstrated that D2 and D3 were able to grow in SCID-hu mice, while D1 and D4 were not viable. Interestingly, co-infection of the implant with the D1 and D4 viruses could compensate their respective growth defect in vivo. The results demonstrated that rescuing viral epithelial tropism is not sufficient to revert the attenuation phenotype of AD169 or Towne, and pathogenic genes are located in the segments missing in D1 and D4 viruses. (C) 2016 Wiley Periodicals, Inc.