Reconstitution of an infectious human endogenous retrovirus.
Reconstitution of an infectious human endogenous retrovirus.
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DOI：
10.1371/journal.ppat.0030010
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发表时间：
2007-01
期刊：
影响因子：
6.7
通讯作者：
Bieniasz PD
中科院分区：
文献类型：
--
作者：
Lee YN;Bieniasz PD
人类基因组代表了古代逆转录病毒的化石记录，这些病毒曾经在当代人类的祖先中复制。事实上，大约8%的人类DNA由可识别的逆转录病毒序列组成。尽管偶尔有报道将人类内源性逆转录病毒（HERV）表达与人类疾病联系起来，但几乎所有HERV基因组都含有明显的失活突变，并且没有一个被认为能够复制。尽管如此，HERV的一个家族，即HERV-K（HML-2），可能在不到100万年前在人类祖先中复制。通过推导出一个共有序列，我们重建了一个前病毒克隆（HERV-KCON），它可能类似于在过去几百万年内进入人类基因组的HERV-K（HML-2）变体的祖先。我们发现HERV-KCON Gag和蛋白酶蛋白介导有效的组装和加工成逆转录病毒样颗粒。此外，插入HERV-KCON基因组并包装到HERV-K颗粒中的报告基因能够以需要逆转录的方式进行感染性转移和稳定整合。此外，我们表明HERV-KCON Env能够假型化HIV-1颗粒并介导进入人类和非人类细胞系。此外，我们发现HERV-KCON对人逆转录病毒限制性因子三联基序5α和载脂蛋白B mRNA编辑酶催化多肽样（APOBEC）3G的抑制具有抗性，但被APOBEC 3F抑制。总的来说，这种灭绝的传染性病原体以功能形式从分子化石中复活，应该能够研究这种古老人类逆转录病毒的分子病毒学和致病潜力。逆转录病毒基因组整合到宿主细胞的基因组中。如果特定逆转录病毒的靶细胞包括生殖系细胞，例如，精子或卵细胞，那么逆转录病毒基因组可以像细胞基因一样遗传。所谓的“内源性”逆转录病毒在包括人类在内的许多生物体的基因组中积累了整个进化过程。虽然现代人类所有已知的内源性逆转录病毒都不能作为逆转录病毒复制，但人类基因组代表了曾经感染我们祖先的古老逆转录病毒的化石记录。在这项研究中，现代人类DNA中“死亡”的内源性逆转录病毒基因组的集合被用来推断祖先逆转录病毒的近似序列，人类内源性逆转录病毒（HERV）-K，现在被认为已经灭绝。合成了一个假祖先HERV-K DNA序列，并用于产生可以重建HERV-K复制周期的病毒蛋白质和RNA。因此，曾经灭绝的逆转录病毒的复制和生物学现在可以在实验室中进行研究。有趣的是，重建的HERV-K复制实验，以及重建的HERV-K DNA序列与现代人类DNA中死亡的HERV-K的比较表明，HERV-K可能在人类中部分被诱导逆转录病毒DNA突变的宿主防御所消灭，并且伪祖先HERV-K的重建逆转了这些变化。
The human genome represents a fossil record of ancient retroviruses that once replicated in the ancestors of contemporary humans. Indeed, approximately 8% of human DNA is composed of sequences that are recognizably retroviral. Despite occasional reports associating human endogenous retrovirus (HERV) expression with human disease, almost all HERV genomes contain obviously inactivating mutations, and none are thought to be capable of replication. Nonetheless, one family of HERVs, namely HERV-K(HML-2), may have replicated in human ancestors less than 1 million years ago. By deriving a consensus sequence, we reconstructed a proviral clone (HERV-KCON) that likely resembles the progenitor of HERV-K(HML-2) variants that entered the human genome within the last few million years. We show that HERV-KCON Gag and protease proteins mediate efficient assembly and processing into retrovirus-like particles. Moreover, reporter genes inserted into the HERV-KCON genome and packaged into HERV-K particles are capable of infectious transfer and stable integration in a manner that requires reverse transcription. Additionally, we show that HERV-KCON Env is capable of pseudotyping HIV-1 particles and mediating entry into human and nonhuman cell lines. Furthermore, we show that HERV-KCON is resistant to inhibition by the human retrovirus restriction factors tripartite motif 5α and apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like (APOBEC) 3G but is inhibited by APOBEC 3F. Overall, the resurrection of this extinct infectious agent in a functional form from molecular fossils should enable studies of the molecular virology and pathogenic potential of this ancient human retrovirus. Retrovirus genomes integrate into the genomes of host cells. If the target cells of a particular retrovirus include germ-line cells, e.g., sperm or egg cells, then retroviral genomes can be inherited like cellular genes. So-called “endogenous” retroviruses have accumulated throughout evolution in the genomes of many organisms, including humans. While all known endogenous retroviruses of modern humans are unable to replicate as retroviruses, the human genome represents a fossil record of ancient retroviruses that once infected our ancestors. In this study, a collection of “dead” endogenous retroviral genomes in modern human DNA was used to deduce the approximate sequence of an ancestral retrovirus, human endogenous retrovirus (HERV)-K, that is now thought to be extinct. A pseudo-ancestral HERV-K DNA sequence was synthesized and used to produce viral proteins and RNA that could reconstitute the HERV-K replication cycle. Thus, the replication and biology of a once-extinct retrovirus can now be studied in the laboratory. Interestingly, reconstituted HERV-K replication experiments, and comparison of the reconstituted HERV-K DNA sequence with the dead HERV-Ks in modern human DNA, suggests that HERV-K may have been extinguished in humans in part by host defenses that induce mutation of retroviral DNA and that the reconstitution of the pseudo-ancestral HERV-K reversed these changes.
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影响因子：
64.5
作者：
Harris, RS;Bishop, KN;Malim, MH
通讯作者：
Malim, MH
DOI：
10.1073/pnas.0307800101
发表时间：
2004-04-06
影响因子：
11.1
作者：
Belshaw, R;Pereira, V;Tristem, M
通讯作者：
Tristem, M
影响因子：
56.9
作者：
Bishop, KN;Holmes, RK;Malim, MH
通讯作者：
Malim, MH
DOI：
10.1073/pnas.0307885100
发表时间：
2004-02-10
影响因子：
11.1
作者：
Hughes, JF;Coffin, JM
通讯作者：
Coffin, JM
影响因子：
5.4
作者：
Dewannieux, M;Blaise, S;Heidmann, T
通讯作者：
Heidmann, T