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标题: 重点关注：科学家于血液中发现新病毒，类似于丙型肝炎 [打印本页]

作者: rentianyixu 时间: 2015-9-26 22:20
标题: 重点关注：科学家于血液中发现新病毒，类似于丙型肝炎
重点关注：科学家于血液中发现新病毒，类似于丙型肝炎

哥伦比亚大学病毒学教授Amit Kapoor领导的研究团队开发出一种新型且复杂的测序技术，能应用于DNA和RNA片段。

　　以1974年至1980年间接受过输血，且在输血前和输血后都留存有血液样本为研究对象，运用“深度测序”技术，研究团队捕获到已知病毒的核酸序列，并同时在两个输血后血液样本中发现一种新病毒。

　　新病毒类似于丙型肝炎

　　该病毒，属于人类pegivirus病毒属，故将其命名为人类hepegivirus 1(HHpgV-1)病毒。虽然丙型肝炎病毒会导致严重的肝功能损伤，但是HHpgV-1却是无害的，研究显示甚至是有益的。

　　Kapoor表示，许多人清楚人类能够与很多细菌共存，但是他们没有意识到这同样适用于一些病毒。相关研究成果于9月22日发表在《mBio》。

　　Kapoor和他的研究团队扩大样本量，但是没有再发现HHpgV-1序列。

　　随后，研究人员继续对一批不同的存储血液样本(来自于106位有输血史的血友病患者)分析，在超过两份血液样本中发现了HHpgV-1序列。但是没有证据表明该序列与疾病有关联。

　　研究人员无法从存储血液中分离出病毒，也没有办法用细胞培养该病毒，但是它又确实存在。

　　阿尔伯达大学的病毒学家Michael Houghton表示，尽管污染经常颠覆新病毒的发现，但是HHpgV-1序列看起来很真实。新病毒的发现虽然存在很多未知，但是它的发现本身就阐明了深度测序技术用于检测新病毒的强大功能。

　　新病毒是否与疾病相关?有待研究

　　旧金山血液系统研究所创办人之一、美国政府血液安全咨询组前成员、实验病理学家Michael Busch表示，血液存储中心对HHpgV-1病毒采取行动还为时尚早。他指出，很多血液制品，例如血浆，经过过滤和失活过程，可能会消除HHpgV-1。

　　研究表明，感染艾滋病病毒的人能够从hepegivirus病毒感染中受益，hepegivirus病毒由一部分HHpgV-1序列组成。他表示：“有明确证据表明，它减少了艾滋病毒的发病机制。”

　　Kapoor表示，现在面临的主要挑战是开发一种抗体，能够在大群体样本中检测是否感染有HHpgV-1。

　　基于该抗体，研究人员才能够将存在HHpgV-1抗体的健康人群与对照组比较，最终获得HHpgV-1是否与疾病相关联的有力证据。

　　Busch表示，几乎每年，科学家们都会发现一种新病毒，其中有一些病毒通过血液传播。

　　研究人员开始关注：这些不同的新型变异病毒来自哪里?它们是最近才出现还是已经与人类共存了很长时间?

来源：医学论坛网

作者: rentianyixu 时间: 2015-9-26 22:21
MBio. 2015 Sep 22;6(5). pii: e01466-15. doi: 10.1128/mBio.01466-15.
Virome Analysis of Transfusion Recipients Reveals a Novel Human Virus That Shares Genomic Features with Hepaciviruses and Pegiviruses.
Abstract
To investigate the transmission of novel infectious agents by blood transfusion, we studied changes in the virome composition of blood transfusion recipients pre- and posttransfusion. Using this approach, we detected and genetically characterized a novel human virus, human hepegivirus 1 (HHpgV-1), that shares features with hepatitis C virus (HCV) and human pegivirus (HPgV; formerly called GB virus C or hepatitis G virus). HCV and HPgV belong to the genera Hepacivirus and Pegivirus of the family Flaviviridae. HHpgV-1 was found in serum samples from two blood transfusion recipients and two hemophilia patients who had received plasma-derived clotting factor concentrates. In the former, the virus was detected only in the posttransfusion samples, indicating blood-borne transmission. Both hemophiliacs were persistently viremic over periods of at least 201 and 1,981 days. The 5' untranslated region (UTR) of HHpgV-1 contained a type IV internal ribosome entry site (IRES), structurally similar to although highly divergent in sequence from that of HCV and other hepaciviruses. However, phylogenetic analysis of nonstructural genes (NS3 and NS5B) showed that HHpgV-1 forms a branch within the pegivirus clade distinct from HPgV and homologs infecting other mammalian species. In common with some pegivirus variants infecting rodents and bats, the HHpgV-1 genome encodes a short, highly basic protein upstream of E1, potentially possessing a core-like function in packaging RNA during assembly. Identification of this new human virus, HHpgV-1, expands our knowledge of the range of genome configurations of these viruses and may lead to a reevaluation of the original criteria by which the genera Hepacivirus and Pegivirus are defined.
IMPORTANCE:
More than 30 million blood components are transfused annually in the United States alone. Surveillance for infectious agents in the blood supply is key to ensuring the safety of this critical resource for medicine and public health. Here, we report the identification of a new and highly diverse HCV/GB virus (GBV)-like virus from human serum samples. This new virus, human hepegivirus 1 (HHpgV-1), was found in serum samples from blood transfusion recipients, indicating its potential for transmission via transfusion products. We also found persistent long-term HHpgV-1 viremia in two hemophilia patients. HHpgV-1 is unique because it shares genetic similarity with both highly pathogenic HCV and the apparently nonpathogenic HPgV (GBV-C). Our results add to the list of human viruses and provide data to develop reagents to study virus transmission and disease association and for interrupting virus transmission and new human infections.

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