白開水
就為了能自由地說點真話
2015年11月9號，包括石正英在內的15位科學家聯合發表了一篇名為《類似薩斯病毒的一種蝙蝠冠狀病毒顯示出可能感染人類的能力》。在這篇論文中，作者揭示了一種人造病毒可以感染人類的能力，隨後招致了來自各界的爭論，其中一篇是美國科學家巴特勒的文章
《人造蝙蝠病毒引發有關風險研究的爭論 》。這篇文章警告這種實驗的危險性，以及人造病毒可能會帶來人類災難。
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
與SARS相關的實驗室製造的冠狀病毒可以感染人類細胞。
這個辯論是關於一項創造新型蝙蝠冠狀病毒（與導致SARS的病毒有關）的混合版本病毒的實驗引發了關於可能的大規模感染流行性病毒的工程實驗是否值得去冒險。
在11月9日發表於《自然醫學》（Nature Medicine1）上的一篇文章中，科學家研究了一種名為SHC014的病毒，該病毒在中國的馬蹄蝠中發現。 研究人員創造了一種由SHC014的表麵蛋白和SARS病毒的骨架組成的嵌合病毒，SARS病毒的骨架已經適應於在小鼠中生長並模仿人類疾病。 嵌合體病毒感染了人類氣呼吸道細胞-證明SHC014的表麵蛋白具有與呼吸道細胞上的關鍵受體結合並感染它們的必要結構。 它也引起小鼠產生疾病，但沒有殺死它們。
盡管從蝙蝠分離出的幾乎所有冠狀病毒都不能與人類關鍵的受體結合，但SHC014並不是第一個可以結合的病毒。 2013年，研究人員首次在分離自同一蝙蝠種群的不同冠狀病毒中報告了這種能力。
研究人員說，這一發現加劇了人們的懷疑，即能夠直接感染人類的蝙蝠冠狀病毒（而不是首先需要在中間動物宿主中進化）。
但是其他病毒學家質疑從實驗中收集的信息是否可以證明潛在的風險。 盡管很難評估任何風險的程度，但巴黎巴斯德研究所的病毒學家西蒙·韋恩·霍布森（Simon Wain-Hobson）指出，研究人員創造了一種新型病毒，該病毒在人細胞中“生長良好”。 他說：“如果病毒逃脫了，沒有人能夠預測其發展軌跡。
創建一個奇美拉（希臘神話中會噴火的怪獸，是獅子、蟒蛇和山羊的結合體，這裏指雜交後產生的新物種）
該論點實質上是關於是否允許進行實驗室研究，以增加危險病原體的毒性，造成傳播容易或擴大宿主範圍的辯論的重演，這就是所謂的“功能獲得性”研究。 2014年10月，美國政府暫停了對引起SARS，流感和MERS（中東呼吸綜合症，一種由病毒偶發性地從駱駝向人傳播的致命疾病）的病毒研究的聯邦資助。
北方大學傳染病研究人員拉爾夫·巴裏克（Ralph Baric）說，因為該研究已經在美國暫停執行令之前就已經進行了，所以美國國立衛生研究院（NIH）允許該研究在機構審查期間繼續進行。 該研究的合著者，位於教堂山的卡羅萊納州。 他說，美國國立衛生研究院最終得出的結論是，這項工作的風險並不高，因此可以繼續下去。
但是Wain-Hobson不讚成這項研究，因為他說，它提供的益處很小，並且幾乎沒有揭示蝙蝠中野生SHC014病毒對人類構成的風險。
研究中的其他實驗表明，野生蝙蝠中的病毒需要進化以對人類構成任何威脅-盡管不能排除，但這種變化可能永遠不會發生。 Baric和他的團隊從其基因組序列重建了野生病毒，發現該病毒在人類細胞培養物中生長緩慢，並且在小鼠中未引起任何重大疾病。
“這項工作的唯一影響是在實驗室中創造了一種新的非自然風險，”新澤西州皮斯卡塔韋的羅格斯大學分子生物學家和生物防禦專家理查德·埃布賴特（Richard Ebright）表示同意。 Ebright和Wain-Hobson都是對功能獲得研究的長期批評家。
該研究的作者在他們的論文中也承認，資助者將來可能會三思而後行。 他們寫道：“科學審查小組可能認為類似的研究目的在於：基於難以進行的高風險循環株創造一種嵌合病毒，”他補充說，需要就“這些類型的嵌合病毒研究是否值得進一步調查以及所涉及的固有風險”進行討論。
有用的研究
但是巴裏奇和其他人說，這項研究確實有好處。 2013年論文的共同作者彼得·達薩克（Peter Daszak）說，研究發現“將這種病毒從候選的新興病原體轉移到明顯的危險中”。 Daszak是總部位於紐約市的國際科學家網絡EcoHealth Alliance的總裁，該網絡從全球新興疾病熱點中的動物和人類中采集病毒。
Daszak同意，在人類細胞培養和動物模型中測試雜交病毒的研究相對於野生病毒的威脅來說隻能說有限。 但是他認為，它們可以幫助指出應該優先考慮哪些病原體，以引起進一步的研究關注。
Baric說，沒有這個（嵌合）實驗，SHC014病毒仍將被視為不是威脅。 以前，科學家在分子模型和其他研究的基礎上認為，它不應該感染人類細胞。但是 他說，最新的工作表明該病毒已經克服了關鍵的障礙，例如能夠鎖存在人類受體上並有效感染人類呼吸道細胞。 “我想你不能忽略這一點。”他計劃對這種病毒在非人類靈長類動物中進行進一步的研究，這可能會產生與人類更相關的數據。
原文和鏈接如下：
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.
來源：《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
