Five cloned piglets, genetically modified so that their organs are much less likely to be rejected by a human donor recipient, have been born in the US.
More than 62,000 people in the US alone are waiting to receive donated hearts, lungs, livers, kidneys and pancreases. The number of human donors falls far short of demand. Pig organs are of a similar size to human organs, and some scientists hope they might be used to help meet the shortfall. But previous attempts to transplant unaltered pig tissue into humans have failed, due to immune rejection of the tissue.
在美國已誕生了5只基因改良的克隆小豬,這使得它們的器官在植入人體時產生排異反應的可能性大為縮小。
僅僅在美國就有6.2萬多人在等待被捐獻出的心臟、肺、肝臟、腎臟和胰臟,器官捐獻者的人數(shù)遠遠滿足不了要求。豬的器官大小與人的器官相似,一些科學家希望它們可用于彌補器官短缺問題。但是,由于種間組織免疫系統(tǒng)的相互排異反應,從前那些用未經改良的豬器官做的移植試驗都失敗了。
The five piglets, born on Christmas Day, lack a gene for an enzyme that adds a sugar to the surface of pig cells. The sugar would trigger a patient's immune system into launching an immediate attack.
"This advance provides a near-time solution for overcoming the shortage of human organs for transplants, as well as insulin-producing cells to cure diabetes," says David Ayares, vice president of research at PPL Therapeutics, US division, where the pigs were created. " This is the key gene for overcoming the early stage of rejection."
圣誕節(jié)出生的這5只小豬,缺少一種使豬的細胞表面加上某種糖類物質的酶的基因。正是這種糖引發(fā)病人的免疫系統(tǒng)立即產生免疫排異反應。
培育出這些小豬的PPL醫(yī)療公司美國分部的研究項目副總裁大衛(wèi)·阿亞里斯說:"這項科研進展及時解決了目前所面臨的人體器官移植來源短缺問題,以及治療糖尿病所需的生產胰島素的細胞。這是個解決早期排異反應的關鍵基因。"
However, scientists warn that much more work is necessary before organs from copies of the pigs could be transplanted into humans. Human genes will need to be added, to prevent rejection of the organ in the long-term. There are also conerns that pig viruses could infect organ recipients.
Cloning techniques were vital to the production of the pigs. Genes can only be knocked out in a single cell. Cloning of these single cells then allowed the creation of a whole animal in which the gene was knocked out in every cell. But the PPL researchers have succeeded in knocking out only one copy of the gene for the enzyme, called alpha 1，3 galactosyl transferase. The team will now attempt to knock out both copies of the gene.
但是,科學家們提醒說,在由克隆豬所提供的器官能夠順利植入人體以前,還有很多必需的工作要做?？赡軙枰偌由先梭w的基因以使這些器官能夠長期免于排異反應。豬的病毒對接受器官的人的感染,也是個值得關注的問題。
克隆技術是培育這些豬的關鍵?；虻娜コ挥性趩蝹€細胞中才能進行?？寺∵@些單細胞然后再將其培育成一只完整的動物,這樣動物身上的每個細胞中的這種基因就都被去除了。但是,PPL醫(yī)療公司的研究人員只是成功地去除了產生這種叫α1,3半乳糖轉移酶的基因的一個副本。他們在試圖將這個基因的兩個副本都去除。
"There will also be other genes we will incorporate into our program," Ayares says. "We don't think that one gene is going to produce an organ that's going to be the end-all for transplantation. We're going to have to add two to three human genes as well."
The team will also conduct tests to investigate whether so-called porcine endogenous retroviruses (PERVS)from the pigs could infect human cells in culture. But Ayares hopes that organs created from PPL pigs could be transplanted into patients within five years.
"But although a lot of the stem cell work is very exciting, we're still very far off being able to grow an organ in a culture dish," says Julia Greenstein of Immerge Bio Therapeutics in Charlestown, US, who is working on creating similar knock-out pigs with researchers at the University of Missouri.
阿亞里斯說:"我們的項目也會包括其他基因,我們覺得掌握一個基因培育的器官并不能徹底解決器官移植面臨的所有問題。我們得再加入兩到三個人類基因的研究。"
該小組還將通過實驗驗證是否豬身上的內生性逆轉濾過性病毒(一種致癌病毒)會在移植培育過程中感染到人身上。但阿亞里斯希望在5年內PPL醫(yī)療公司培育的器官能夠被移植到人身上。
就職美國查爾斯城浸沒生物醫(yī)療公司的朱利婭·格林斯坦,正在密蘇里大學和同事們從事著類似的研究，即培育去除某種基因的小豬。她說:"盡管干細胞研究的許多工作令人非常激動,但在培養(yǎng)器中成功地培育出器官還為時過早。
More than 62,000 people in the US alone are waiting to receive donated hearts, lungs, livers, kidneys and pancreases. The number of human donors falls far short of demand. Pig organs are of a similar size to human organs, and some scientists hope they might be used to help meet the shortfall. But previous attempts to transplant unaltered pig tissue into humans have failed, due to immune rejection of the tissue.
在美國已誕生了5只基因改良的克隆小豬,這使得它們的器官在植入人體時產生排異反應的可能性大為縮小。
僅僅在美國就有6.2萬多人在等待被捐獻出的心臟、肺、肝臟、腎臟和胰臟,器官捐獻者的人數(shù)遠遠滿足不了要求。豬的器官大小與人的器官相似,一些科學家希望它們可用于彌補器官短缺問題。但是,由于種間組織免疫系統(tǒng)的相互排異反應,從前那些用未經改良的豬器官做的移植試驗都失敗了。
The five piglets, born on Christmas Day, lack a gene for an enzyme that adds a sugar to the surface of pig cells. The sugar would trigger a patient's immune system into launching an immediate attack.
"This advance provides a near-time solution for overcoming the shortage of human organs for transplants, as well as insulin-producing cells to cure diabetes," says David Ayares, vice president of research at PPL Therapeutics, US division, where the pigs were created. " This is the key gene for overcoming the early stage of rejection."
圣誕節(jié)出生的這5只小豬,缺少一種使豬的細胞表面加上某種糖類物質的酶的基因。正是這種糖引發(fā)病人的免疫系統(tǒng)立即產生免疫排異反應。
培育出這些小豬的PPL醫(yī)療公司美國分部的研究項目副總裁大衛(wèi)·阿亞里斯說:"這項科研進展及時解決了目前所面臨的人體器官移植來源短缺問題,以及治療糖尿病所需的生產胰島素的細胞。這是個解決早期排異反應的關鍵基因。"
However, scientists warn that much more work is necessary before organs from copies of the pigs could be transplanted into humans. Human genes will need to be added, to prevent rejection of the organ in the long-term. There are also conerns that pig viruses could infect organ recipients.
Cloning techniques were vital to the production of the pigs. Genes can only be knocked out in a single cell. Cloning of these single cells then allowed the creation of a whole animal in which the gene was knocked out in every cell. But the PPL researchers have succeeded in knocking out only one copy of the gene for the enzyme, called alpha 1，3 galactosyl transferase. The team will now attempt to knock out both copies of the gene.
但是,科學家們提醒說,在由克隆豬所提供的器官能夠順利植入人體以前,還有很多必需的工作要做?？赡軙枰偌由先梭w的基因以使這些器官能夠長期免于排異反應。豬的病毒對接受器官的人的感染,也是個值得關注的問題。
克隆技術是培育這些豬的關鍵?；虻娜コ挥性趩蝹€細胞中才能進行?？寺∵@些單細胞然后再將其培育成一只完整的動物,這樣動物身上的每個細胞中的這種基因就都被去除了。但是,PPL醫(yī)療公司的研究人員只是成功地去除了產生這種叫α1,3半乳糖轉移酶的基因的一個副本。他們在試圖將這個基因的兩個副本都去除。
"There will also be other genes we will incorporate into our program," Ayares says. "We don't think that one gene is going to produce an organ that's going to be the end-all for transplantation. We're going to have to add two to three human genes as well."
The team will also conduct tests to investigate whether so-called porcine endogenous retroviruses (PERVS)from the pigs could infect human cells in culture. But Ayares hopes that organs created from PPL pigs could be transplanted into patients within five years.
"But although a lot of the stem cell work is very exciting, we're still very far off being able to grow an organ in a culture dish," says Julia Greenstein of Immerge Bio Therapeutics in Charlestown, US, who is working on creating similar knock-out pigs with researchers at the University of Missouri.
阿亞里斯說:"我們的項目也會包括其他基因,我們覺得掌握一個基因培育的器官并不能徹底解決器官移植面臨的所有問題。我們得再加入兩到三個人類基因的研究。"
該小組還將通過實驗驗證是否豬身上的內生性逆轉濾過性病毒(一種致癌病毒)會在移植培育過程中感染到人身上。但阿亞里斯希望在5年內PPL醫(yī)療公司培育的器官能夠被移植到人身上。
就職美國查爾斯城浸沒生物醫(yī)療公司的朱利婭·格林斯坦,正在密蘇里大學和同事們從事著類似的研究，即培育去除某種基因的小豬。她說:"盡管干細胞研究的許多工作令人非常激動,但在培養(yǎng)器中成功地培育出器官還為時過早。