中国科学家基因编辑治疗艾滋病 向"治愈"又迈出一步

The 27-year-old patient's prospects were bleak. In May 2016, he found out he had AIDS. Two weeks later, he was told he had acute lymphoblastic leukemia.
这位27岁的病人前景黯淡。2016年5月，他发现自己患有艾滋病。两周后，他被告知患有急性淋巴细胞白血病。

But doctors offered the Chinese citizen a ray of hope: a bone marrow transplant to treat his cancer and an extra experimental treatment to try to rid his system of HIV, according to a new paper published in The New England Journal of Medicine.
但根据《新英格兰医学杂志》最新发表的一篇论文，医生们给这位中国公民带来了一线希望：通过骨髓移植来治疗他的癌症，并进行另外的实验性治疗，试图清除他体内的艾滋病病毒。

This involved using the gene editing tool CRISPR-Cas9 to delete a gene known as CCR5 from bone marrow stem cells taken from a donor, before transplanting them into the patient, Peking University scientists said in the study.
参与研究的北京大学科学家说，治疗手段包括使用基因编辑工具CRISPR-Cas9从捐赠者的骨髓干细胞中删除一种名为CCR5的基因，然后将干细胞移植到患者体内。

"After being edited, the cells -- and the blood cells they produce -- have the ability to resist HIV infection," lead scientist Deng Hongkui told cnn Friday.
“经过编辑后，这些细胞——以及它们产生的血液细胞——有能力抵抗艾滋病毒感染，”首席科学家邓宏魁在上周五（9月13日）告诉美国有线新闻网。

People who carry defective copies of CCR5 are highly immune to HIV, because the virus uses a protein made by this gene to gain entry into an infected person's cells. Two men, known as the Berlin patient and the London patient, became the first people in the world to be cured of HIV after receiving bone marrow transplants from donors who had the mutation naturally.
携带有发生突变的CCR5基因拷贝的人对艾滋病毒具有很高的免疫力，因为艾滋病毒利用这种基因产生的蛋白质进入感染者的细胞。“柏林患者”和“伦敦患者”在接受了来自天生携带有这种基因突变的捐赠者的骨髓移植后，成为世界上首批被治愈的艾滋病毒感染者。

The patient agreed and the experiment was carried out in the summer of 2017. It was the first time CRISPR-Cas9 was used on a HIV patient. In early 2019, a full 19 months after the treatment was administered, "the acute lymphoblastic leukemia was in complete remission and donor cells carrying the ablated CCR5 persisted," the scientists said in the paper.
在患者同意后，实验于2017年夏天进行。这是基因编辑工具CRISPR-Cas9首次用于艾滋病毒患者。2019年初，也就是接受治疗整整19个月后，“急性淋巴细胞白血病完全缓解，携带有经过编辑的CCR5基因的供体细胞持续存在，”科学家在论文中说。

But there weren't enough of them to eradicate the HIV virus in the patient's body. After transplantation, only approximately 5% to 8% of the patient's bone marrow cells carried the CCR5 edit, according to the researchers. "In the future, further improving the efficiency of gene-editing and optimizing the transplantation procedure should accelerate the transition to clinical applications," said Deng.
但这还不足以消灭病人体内的艾滋病毒。研究人员说，移植后，只有大约5%到8%的患者骨髓细胞携带这种经过编辑的基因。邓宏魁说，“在未来，进一步提高基因编辑的效率和优化移植程序等措施应该会加速向临床应用的转变。”

But he doesn't see this as a setback."The main purpose of the study was to evaluate the safety and feasibility of genetically-edited stem cell transplantation for AIDS treatment," said Deng.
但他不认为这个治疗是一次失败。“这项研究的主要目的是评估基因编辑干细胞移植治疗艾滋病的安全性和可行性，”邓宏魁说。

According to Deng, this was a success: the scientists didn't detect any gene editing-related adverse events, even if "more long-term in-depth studies are needed for off-target effects and other safety assessments," Deng said.
他认为这个试验很成功：科学家们没有发现任何与基因编辑相关的不良事件，邓宏魁说，即使“需要更长期深入的研究来进行脱靶效应和其他安全评估。”

The CCR5 gene mutation has been associated with a 21% increased risk of dying early, according to a paper published in Nature in June, though it's unclear why.
《自然》杂志今年6月发表的一篇论文称，CCR5基因突变与早逝风险增加21%有关，不过原因尚不清楚。

The team that conducted the study had previously transplanted edited CCR5 human cells into mice, making them resistant to HIV. American scientists have carried out similar experiments on humans, with some success, using an older gene editing tool called zinc finger nuclease.
进行这项研究的团队此前曾将CCR5编辑过的人类细胞移植到小鼠体内，使其对艾滋病毒具有抵抗力。美国科学家已经在人类身上进行了类似的实验，并取得了一些成功，他们使用了一种更古老的被称为锌指核酸酶技术的基因编辑工具。

China has invested heavily in gene-editing technology, making biotech one the priorities of its Five-Year Plan announced in 2016. The central government has bankrolled research into a number of world "firsts," including the first use of the gene-editing tool CRISPR-Cas9 in humans in 2016 and the first reported use of gene editing technology to modify nonviable human embryos in 2015.
中国在基因编辑技术上投入巨资，将生物技术列为2016年宣布的五年规划（十三五规划）的重点之一。中国政府资助了多项堪称世界“第一”的研究，包括2016年首次在人类身上使用基因编辑工具CRISPR-Cas9，以及2015年首次使用基因编辑技术修改无法存活的人类胚胎。

Deng Hongkui remains a strong believer in CRISPR-Cas9. He thinks it could "bring a new dawn" to blood-related diseases such as AIDS, sickle anemia, hemophilia and beta thalassemia and that, thanks to this new technology, "the goal of a functional cure for AIDS is getting closer and closer."
邓宏魁仍然是基因编辑工具CRISPR-Cas9的坚定信徒。他认为这将为血液相关疾病带来“新的曙光”，比如艾滋病、镰状细胞贫血、血友病和乙型地中海贫血。而且，由于这项新技术，“人们距离功能性治愈艾滋病的目标越来越接近”。