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为什么有些人对艾滋病有天生的免疫力?

刘君 发表于 2008/12/6 16:24 854次点击 | 收藏

为什么有些人对艾滋病有天生的免疫力?

2008-12-05 16:25:14 来源: 网易探索(广州) 
  •   为什么有些人对艾滋病有天生的免疫力?医学专家发现他们体内有一种免疫细胞CD8+T淋巴细胞,而且这种细胞的作用方式使人具有特别强的免疫能力。

新的艾滋病治疗方式?在显微镜下CD8+T淋巴细胞包含有穿孔素和颗粒酶。看上去荧光闪闪,绿色的是穿孔素,白色的是颗粒酶B,红色的是艾滋病病毒的杀手T细胞

网易探索讯 据国外媒体报道有些人对艾滋病有一种天生的免疫能力,他们能够控制艾滋病病毒侵入自己身体,医学专家发现他们体内有一种免疫细胞CD8+T淋巴细胞,而且这种细胞的作用方式使人具有特别强的免疫能力。这一新的医学突破为艾滋病的防治指明了方向。

这项新的研究发表在权威杂志《免疫》上,分析了一些对艾滋病具有免疫能力的人的体内机制,解释了他们为什么能够控制病毒,以及如何消灭体内受艾滋病感染的细胞。美国马里兰州贝塞斯达的国立卫生研究院免疫学家、艾滋病毒疫苗研究者马克-康诺斯(MarkConnors)说:“这一发现是这一领域的一大突破。

天生的艾滋病杀手

康诺斯说:“有些人(小于0.5%)第一次感染艾滋病后几十年都不犯病,因为他们控制了病毒的扩散,同时让病毒死于无形之中。曾经有研究表明这种控制能力与体内的一种免疫细胞——CD8+T淋巴细胞有关,这种免疫细胞能发现并消灭被病毒感染的细胞。但当时无法解释究竟为什么会这样。

现在康诺斯和他的研究团队发现有较多CD8+T细胞的人通过将毒液输送到受感染的细胞,从而控制艾滋病的发作。为了获得这一发现,科学家们制订了一系列敏感的测试,分析存在的这些T细胞,以及它们消灭感染艾滋病毒的能力。他们发现CD8+T细胞在受感染的人身上生长得非常迅速,从而比一般人更能控制艾滋病。

但他们同时还发现不仅仅是CD8+T淋巴细胞数量增多的问题,还与这些细胞的作用方式紧密相关,因为它们能够生长和提供一对特别的分子“穿孔素”和“颗粒酶B”。穿孔素,顾名思义,就是能够在靶细胞膜上穿孔的物质。细胞被穿孔了,颗粒酶B就能够进入并破坏受感染的细胞。

挑战长期持有的模式

研究结果对长期持有的模式进行了挑战。康诺斯称,以前大家认为,我们的免疫记忆细胞,比如CD8+T细胞,它们的作用就像是“一个装满子弹的枪,根据需要选择子弹杀死病毒。”康纳斯认为,在现实中,这些“记忆细胞”需要重新刺激,在反复接触病毒后需要重新刺激才能够保护我们。

美国马里兰州巴尔的摩市约翰霍普金斯大学医学科学家乔尔-布兰森(JoelBlankson)说:“这项研究成果对发展疫苗意义重大,研究成果为我们评估疫苗疗效提供了新的重要的参数。”他虽然并没有参与其中的工作,但又补充说这项研究“也是一个重要的概念证明,因为它表明,只要艾滋病毒特效杀手T淋巴细胞得到正确的刺激,就可以诱导它发挥作用,从而有效地杀死受艾滋病毒感染的细胞。”

治疗性疫苗

这意味着我们未来能够生产出一种能够对抗艾滋病感染的治疗性疫苗,而不是单纯的保护感染艾滋病的预防性疫苗。

位于美国费城的夕法尼亚大学免疫学家乔托(GuidoSilvestri)称,他对这项研究抱有很大希望。“这样的研究可能将最终为以免疫为基础的干预铺平道路,这样可以利用人体免疫系统的方式,完全控制甚至消灭艾滋病毒。当然,我们还有很长的路要走,至少10年到20年。但是我们已经向正确方向迈出了重要的一步。”

康诺斯表示,下一步他们的研究将重点将放在为什么大多数人的CD8+T细胞缺乏杀死艾滋病毒感染的细胞的能力。(小尔)

(本文来源:网易探索 )

Why do some people have natural immunity against AIDS?
2008-12-05 16:25:14 Source: Netease Exploration (Guangzhou)
Why do some people have natural immunity against AIDS? Medical experts found in their bodies a CD8 + T cells, immune cells, and this is the way cells in particular have strong immunity.




The new AIDS treatment? Under the microscope CD8 + T lymphocytes contain perforation and granzyme. Look shining fluorescent green is perforin, is a white granzyme B, is a red AIDS virus killer T cells

Netease hearing to explore foreign countries, according to media reports on AIDS that some people have a natural immunity, they can control the AIDS virus invaded his body, medical experts found in their bodies a CD8 + T cells, immune cells, and cells in such a way so that the role of the People have a particularly strong immunity. This new medical breakthrough for AIDS prevention and control of the direction.

The new study published in the journal "Immunity", the analysis of a number of AIDS with the human immune mechanisms in the body, explains why they are able to control the virus in the body and how to eradicate HIV-infected cells. Bethesda, Maryland, USA's National Institutes of Health immunologist, HIV vaccine researchers Mark - Connors (MarkConnors) said: "The findings in this area is a major breakthrough.

Natural killer AIDS

Connors said: "Some people (less than 0.5 percent) for the first time after decades of HIV infection do not fall ill, because they control the spread of the virus, died of the virus so that at the same time being invisible. Studies have shown that this control With a capacity of immune cells in the body - CD8 + T lymphocytes, immune cells that can be found and the eradication of HIV-infected cells. At that time, but can not explain exactly why.

Now Connors and his research team found that more CD8 + T cells through the venom will be transported to the infected cells, which control the onset of AIDS. In order to obtain this discovery, scientists have developed a series of sensitive tests, analysis of the existence of these T cells, and their eradication of HIV infection. They found that CD8 + T cells in infected people has been very rapid growth, which more than the average person to control AIDS.

At the same time, but they also found that only CD8 + T lymphocytes increase in the number of problems with the way these cells are closely related, because they can grow and provide a pair of special molecules, "perform" and "granzyme B". Perforin, as its name implies, is able to target cell membrane perforation of the material. Cells were perforated, granzyme B will be able to enter and destroy infected cells.

Long-term challenge of holding pattern

The results of the long-held model for the challenge. Connors said before we believe that our immune memory cells, such as CD8 + T cells, their role is like "a gun loaded with bullets, according to the need to choose a bullet to kill the virus." Connors believes that In reality, these "memory cells" need to re-stimulate, and after repeated exposure to the virus needs to be able to stimulate protect us.

Baltimore, Maryland, Johns Hopkins University Medical scientists Joel - Branson (JoelBlankson), said: "The research on vaccine development is of great significance for our research to assess efficacy of the vaccine provides a new important parameters. "Although he did not take part in the work, but added that the study" is also an important proof of concept, because it shows that as long as the effects of HIV killer T cells to be the right stimulus, it can be induced to play a role in order to Effective in killing HIV-infected cells. "

Therapeutic vaccine

This means that in the future we will be able to produce a confrontation Therapeutic AIDS vaccine, rather than simply the protection of HIV preventive vaccine.

Philadelphia at Penn's University immunologist Giotto (GuidoSilvestri) said he was very hopeful the study. "This research may eventually be the basis for immunity in order to pave the way for intervention, which can be used the way the body's immune system, or even complete control of the eradication of HIV. Of course, we still have a long way to go, at least 10 years to 20 years. But we have been in the right direction to a significant step forward. "

Connors said the next step of their research will focus on why the majority of CD8 + T cells to kill the lack of HIV-infected cells. (Small Seoul)

(This article Source: Netease Exploration)

来源∶

http://www.zyynb.com/admin/Article_Show.asp?ArticleID=4785

http://www.chinavalue.net/Group/Topic/16772/

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