VOA慢速英语2012 Technology Report - New Research Hopes to Speed Development of HIV Vaccine

 

Technology Report - New Research Hopes to Speed Development of HIV Vaccine¹

This is the VOA Special English Technology Report.

A team of scientists in the United States has created a new type of mouse that has an immune system similar to that of humans. The scientists hope their research with these mice will speed up development of a vaccine to prevent human immunodeficiency virus, or HIV.

Scientists from the Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard are carrying out the new research.

Earlier research has shown that certain individuals with HIV have immune systems that do better at controlling the AIDS virus. These individuals are commonly known as “elite controllers.” They often live longer with the virus and have fewer problems early on.

Todd Allen is one of the lead writers of the new study, which was published in Science Translational Medicine.

TODD ALLEN: “Some people are able to control HIV very well, to very low copies. And what we know is that they express a certain type of host genetics that dictate³ that they target very critical regions of the virus.”

By using the new experimental mice, the researchers hope to learn what it is about the immune systems of these “elite controllers” that causes them to deal with the HIV virus better than others.

The “humanized” mice were created using stem cells and tissues from human donors⁴. Some of this tissue was taken from liver and thymus tissue. The thymus is a large gland⁵ at the bottom of the throat. It trains T-lymphocytes, or T-cells to attack unwelcome microbes, thereby⁶ protecting the body from infection.

When the scientists infected the so-called “humanized” mice with the HIV virus, the T-cell reaction in the mice was the exact same as that of humans.

Earlier research using rhesus monkeys helped scientists understand how the virus attacks cells. These monkeys were seen as good replacements⁷ for humans because they could be easily infected with a primate⁸ version of HIV, known as SIV.

However, genetic² differences in the two versions of the virus and the immune systems suggested that the monkeys were not the best candidates for HIV research.

Todd Allen says the experiments with the new “humanized” mouse more correctly reflected what happens in humans with the AIDs virus.

TODD ALLEN: “So it allows us to take all the discoveries we’ve had in studying individuals infected with HIV in the different immune responses and host genetics that correlate with a better outcome, and translate that now into an animal model where we can actually further manipulate that to understand exactly how these individuals are doing that.”

Mr. Allen and the other researchers hope further studies with the “humanized” mouse will lead to an HIV vaccine.

And that's the VOA Special English Technology Report, Jessica Berman and June Simms, contributing. I'm Steve Ember.

1 vaccine   

n.牛痘苗，疫苗；adj.牛痘的，疫苗的

参考例句：

• The polio vaccine has saved millions of lives.脊髓灰质炎疫苗挽救了数以百万计的生命。
• She takes a vaccine against influenza every fall.她每年秋季接种流感疫苗。

2 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

3 dictate   

v.口授；(使)听写；指令，指示，命令

参考例句：

• It took him a long time to dictate this letter.口述这封信花了他很长时间。
• What right have you to dictate to others?你有什么资格向别人发号施令？

4 donors   

n.捐赠者( donor的名词复数 )；献血者；捐血者；器官捐献者

参考例句：

• Please email us to be removed from our active list of blood donors. 假如你想把自己的名字从献血联系人名单中删去，请给我们发电子邮件。
• About half this amount comes from individual donors and bequests. 这笔钱大约有一半来自个人捐赠及遗赠。 来自《简明英汉词典》

5 gland   

n.腺体，(机)密封压盖，填料盖

参考例句：

• This is a snake's poison gland.这就是蛇的毒腺。
• Her mother has an underactive adrenal gland.她的母亲肾上腺机能不全。

6 thereby   

adv.因此，从而

参考例句：

• I have never been to that city,,ereby I don't know much about it.我从未去过那座城市，因此对它不怎么熟悉。
• He became a British citizen,thereby gaining the right to vote.他成了英国公民，因而得到了投票权。

7 replacements   

n.代替( replacement的名词复数 )；替换的人[物]；替代品；归还

参考例句：

• They infiltrated behind the lines so as to annoy the emery replacements. 他们渗透敌后以便骚扰敌军的调度。 来自辞典例句
• For oil replacements, cheap suddenly looks less of a problem. 对于石油的替代品来说，价格变得无足轻重了。 来自互联网

8 primate   

n.灵长类（目）动物，首席主教；adj.首要的

参考例句：

• 14 percent of primate species are highly endangered.14%的灵长类物种处于高度濒危状态。
• The woolly spider monkey is the largest primate in the Americas.绒毛蛛猴是美洲最大的灵长类动物。