白开水
就为了能自由地说点真话
2015年11月9号，包括石正英在内的15位科学家联合发表了一篇名为《类似萨斯病毒的一种蝙蝠冠状病毒显示出可能感染人类的能力》。在这篇论文中，作者揭示了一种人造病毒可以感染人类的能力，随后招致了来自各界的争论，其中一篇是美国科学家巴特勒的文章
《人造蝙蝠病毒引发有关风险研究的争论 》。这篇文章警告这种实验的危险性，以及人造病毒可能会带来人类灾难。
Engineered bat virus stirs debate over risky research
Lab-made coronavirus related to SARS can infect human cells.
作者：Declan Butler 2015 NOV 12
与SARS相关的实验室制造的冠状病毒可以感染人类细胞。
这个辩论是关于一项创造新型蝙蝠冠状病毒（与导致SARS的病毒有关）的混合版本病毒的实验引发了关于可能的大规模感染流行性病毒的工程实验是否值得去冒险。
在11月9日发表于《自然医学》（Nature Medicine1）上的一篇文章中，科学家研究了一种名为SHC014的病毒，该病毒在中国的马蹄蝠中发现。 研究人员创造了一种由SHC014的表面蛋白和SARS病毒的骨架组成的嵌合病毒，SARS病毒的骨架已经适应于在小鼠中生长并模仿人类疾病。 嵌合体病毒感染了人类气呼吸道细胞-证明SHC014的表面蛋白具有与呼吸道细胞上的关键受体结合并感染它们的必要结构。 它也引起小鼠产生疾病，但没有杀死它们。
尽管从蝙蝠分离出的几乎所有冠状病毒都不能与人类关键的受体结合，但SHC014并不是第一个可以结合的病毒。 2013年，研究人员首次在分离自同一蝙蝠种群的不同冠状病毒中报告了这种能力。
研究人员说，这一发现加剧了人们的怀疑，即能够直接感染人类的蝙蝠冠状病毒（而不是首先需要在中间动物宿主中进化）。
但是其他病毒学家质疑从实验中收集的信息是否可以证明潜在的风险。 尽管很难评估任何风险的程度，但巴黎巴斯德研究所的病毒学家西蒙·韦恩·霍布森（Simon Wain-Hobson）指出，研究人员创造了一种新型病毒，该病毒在人细胞中“生长良好”。 他说：“如果病毒逃脱了，没有人能够预测其发展轨迹。
创建一个奇美拉（希腊神话中会喷火的怪兽，是狮子、蟒蛇和山羊的结合体，这里指杂交后产生的新物种）
该论点实质上是关于是否允许进行实验室研究，以增加危险病原体的毒性，造成传播容易或扩大宿主范围的辩论的重演，这就是所谓的“功能获得性”研究。 2014年10月，美国政府暂停了对引起SARS，流感和MERS（中东呼吸综合症，一种由病毒偶发性地从骆驼向人传播的致命疾病）的病毒研究的联邦资助。
北方大学传染病研究人员拉尔夫·巴里克（Ralph Baric）说，因为该研究已经在美国暂停执行令之前就已经进行了，所以美国国立卫生研究院（NIH）允许该研究在机构审查期间继续进行。 该研究的合著者，位于教堂山的卡罗莱纳州。 他说，美国国立卫生研究院最终得出的结论是，这项工作的风险并不高，因此可以继续下去。
但是Wain-Hobson不赞成这项研究，因为他说，它提供的益处很小，并且几乎没有揭示蝙蝠中野生SHC014病毒对人类构成的风险。
研究中的其他实验表明，野生蝙蝠中的病毒需要进化以对人类构成任何威胁-尽管不能排除，但这种变化可能永远不会发生。 Baric和他的团队从其基因组序列重建了野生病毒，发现该病毒在人类细胞培养物中生长缓慢，并且在小鼠中未引起任何重大疾病。
“这项工作的唯一影响是在实验室中创造了一种新的非自然风险，”新泽西州皮斯卡塔韦的罗格斯大学分子生物学家和生物防御专家理查德·埃布赖特（Richard Ebright）表示同意。 Ebright和Wain-Hobson都是对功能获得研究的长期批评家。
该研究的作者在他们的论文中也承认，资助者将来可能会三思而后行。 他们写道：“科学审查小组可能认为类似的研究目的在于：基于难以进行的高风险循环株创造一种嵌合病毒，”他补充说，需要就“这些类型的嵌合病毒研究是否值得进一步调查以及所涉及的固有风险”进行讨论。
有用的研究
但是巴里奇和其他人说，这项研究确实有好处。 2013年论文的共同作者彼得·达萨克（Peter Daszak）说，研究发现“将这种病毒从候选的新兴病原体转移到明显的危险中”。 Daszak是总部位于纽约市的国际科学家网络EcoHealth Alliance的总裁，该网络从全球新兴疾病热点中的动物和人类中采集病毒。
Daszak同意，在人类细胞培养和动物模型中测试杂交病毒的研究相对于野生病毒的威胁来说只能说有限。 但是他认为，它们可以帮助指出应该优先考虑哪些病原体，以引起进一步的研究关注。
Baric说，没有这个（嵌合）实验，SHC014病毒仍将被视为不是威胁。 以前，科学家在分子模型和其他研究的基础上认为，它不应该感染人类细胞。但是 他说，最新的工作表明该病毒已经克服了关键的障碍，例如能够锁存在人类受体上并有效感染人类呼吸道细胞。 “我想你不能忽略这一点。”他计划对这种病毒在非人类灵长类动物中进行进一步的研究，这可能会产生与人类更相关的数据。
原文和链接如下：
Engineered bat virus stirs debate over risky research
Lab-made coronavirus related to SARS can infect human cells.
12 November 2015
An experiment that created a hybrid version of a bat coronavirus — one related to the virus that causes SARS (severe acute respiratory syndrome) — has triggered renewed debate over whether engineering lab variants of viruses with possible pandemic potential is worth the risks.
In an article published in Nature Medicine1 on 9 November, scientists investigated a virus called SHC014, which is found in horseshoe bats in China. The researchers created a chimaeric virus, made up of a surface protein of SHC014 and the backbone of a SARS virus that had been adapted to grow in mice and to mimic human disease. The chimaera infected human airway cells — proving that the surface protein of SHC014 has the necessary structure to bind to a key receptor on the cells and to infect them. It also caused disease in mice, but did not kill them.
Although almost all coronaviruses isolated from bats have not been able to bind to the key human receptor, SHC014 is not the first that can do so. In 2013, researchers reported this ability for the first time in a different coronavirus isolated from the same bat population2.
The findings reinforce suspicions that bat coronaviruses capable of directly infecting humans (rather than first needing to evolve in an intermediate animal host) may be more common than previously thought, the researchers say.
But other virologists question whether the information gleaned from the experiment justifies the potential risk. Although the extent of any risk is difficult to assess, Simon Wain-Hobson, a virologist at the Pasteur Institute in Paris, points out that the researchers have created a novel virus that “grows remarkably well” in human cells. “If the virus escaped, nobody could predict the trajectory,” he says.
Creation of a chimaera
The argument is essentially a rerun of the debate over whether to allow lab research that increases the virulence, ease of spread or host range of dangerous pathogens — what is known as ‘gain-of-function’ research. In October 2014, the US government imposed a moratorium on federal funding of such research on the viruses that cause SARS, influenza and MERS (Middle East respiratory syndrome, a deadly disease caused by a virus that sporadically jumps from camels to people).
The latest study was already under way before the US moratorium began, and the US National Institutes of Health (NIH) allowed it to proceed while it was under review by the agency, says Ralph Baric, an infectious-disease researcher at the University of North Carolina at Chapel Hill, a co-author of the study. The NIH eventually concluded that the work was not so risky as to fall under the moratorium, he says.
But Wain-Hobson disapproves of the study because, he says, it provides little benefit, and reveals little about the risk that the wild SHC014 virus in bats poses to humans.
Other experiments in the study show that the virus in wild bats would need to evolve to pose any threat to humans — a change that may never happen, although it cannot be ruled out. Baric and his team reconstructed the wild virus from its genome sequence and found that it grew poorly in human cell cultures and caused no significant disease in mice.
“The only impact of this work is the creation, in a lab, of a new, non-natural risk,” agrees Richard Ebright, a molecular biologist and biodefence expert at Rutgers University in Piscataway, New Jersey. Both Ebright and Wain-Hobson are long-standing critics of gain-of-function research.
In their paper, the study authors also concede that funders may think twice about allowing such experiments in the future. "Scientific review panels may deem similar studies building chimeric viruses based on circulating strains too risky to pursue," they write, adding that discussion is needed as to "whether these types of chimeric virus studies warrant further investigation versus the inherent risks involved”.
Useful research
But Baric and others say the research did have benefits. The study findings “move this virus from a candidate emerging pathogen to a clear and present danger”, says Peter Daszak, who co-authored the 2013 paper. Daszak is president of the EcoHealth Alliance, an international network of scientists, headquartered in New York City, that samples viruses from animals and people in emerging-diseases hotspots across the globe.
Studies testing hybrid viruses in human cell culture and animal models are limited in what they can say about the threat posed by a wild virus, Daszak agrees. But he argues that they can help indicate which pathogens should be prioritized for further research attention.
Without the experiments, says Baric, the SHC014 virus would still be seen as not a threat. Previously, scientists had believed, on the basis of molecular modelling and other studies, that it should not be able to infect human cells. The latest work shows that the virus has already overcome critical barriers, such as being able to latch onto human receptors and efficiently infect human airway cells, he says. “I don't think you can ignore that.” He plans to do further studies with the virus in non-human primates, which may yield data more relevant to humans.
来源：《自然周刊》 https://www.nature.com/news/engineered-bat-virus-stirs-debate-over-risky-research-1.18787?fbclid=IwAR3DUjcRIlGF5_d6XOS4mm_ZlzWUwgGaHZZPYVp3_UaznsQWsftDU5EVQDY#/ref-link-2
