图为一个已被艾滋病病毒感染的供体细胞（绿色），正在感染正常细胞（红色）。（图片提供：Benjamin K. Chen，Mount Sinai School of Medicine）
由加州理工学院生物学教授、诺奖获得者大卫·巴尔的摩（David Baltimore）领导的一个研究团队近日发现，艾滋病病毒会利用已感染细胞来接近健康细胞，从而实现病毒大批量传播，这可能是艾滋病病毒在经过抗逆转录病毒药物成功治疗后，仍能在少数受感染细胞中存活的原因。相关研究论文已发表在8月17日的《自然》杂志上。
目前，艾滋病病毒感染细胞有两种方式：一是无细胞传播，即病毒在血浆中移动，遭遇免疫系统细胞（T细胞）时，对其传染；二是细胞间传播，病毒以被感染的供体细胞作为媒介在细胞间传播。一旦发现未受感染的靶细胞，供体细胞便将病毒传染给该细胞。
研究小组分别使用细胞外艾滋病病毒和供体细胞来感染靶细胞。使用的供体细胞缺少一种天然标记HLA-A2，而靶细胞则有这种标记，这将有助科学家分清两种细胞。结果显示，无论是否有抗病毒药物作用，靶细胞都会被感染。
研究人员发现，通过无细胞传播方式感染的细胞在抗病毒药物作用下，数目急剧下降，而即使在大剂量药物的作用下，通过细胞间传播感染的细胞依然是缓慢减少。“我们发现，细胞间传播使更多病毒作用于一个细胞，” 该小组成员Alex Sigal说，“这使得病毒存活的几率大大增加。”这或许能解释，为什么抗病毒药物无法根除艾滋病病毒感染。药物治疗本质上说是一种概率性杀毒，即它们不能100%地杀死病毒。所以，当病毒数量变多时，其存活并感染下一个细胞的几率变大。
另一个可能是艾滋病病毒进入潜伏期，病毒潜伏在细胞的DNA中，聚集成一个病毒库，不发生复制作用，因而药物对其无效。Sigal表示，这两种方式可能存在相互影响。
“确定病毒的细胞间复制是否导致艾滋病病毒库的产生，对研究治疗方案尤为重要”，他说，“我们不能用对付病毒库的方式来对付（细胞间复制）。”理论上来说，通过激活潜伏病毒库中的病毒，有助实现病毒的根除，但如果病毒进入新细胞内，它们将变得难以对付。
“我们下一步要做的是，从生理学水平上了解艾滋病病毒是怎样通过细胞间传播来感染像淋巴结这样的器官，”Sigal说。（本文来源：科学网 徐文杰/编译）
艾滋病不治会早死，早治才康复 艾滋病不治会早死，早治才康复 艾滋病不治会早死，早治才康复 艾滋病不治会早死，早治才康复
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| 图示∶2011年5月正式出版的《中国特色医疗金鉴》登载的刘君主任及其机构事迹 |
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Nobel research team found that the mechanism can not be completely cured of AIDS
2011-08-22 09:58:00 Source: Netease explore
Core Tip: from the California Institute of Technology biology professor, Nobel laureate David Baltimore, has led a research team found that HIV anti-retroviral drugs after successful treatment, still in a small number of infected cells to survive reasons.
The picture shows one has been infected with HIV donor cells (green), normal cells are infected (red). (Photo provided by: Benjamin K. Chen, Mount Sinai School of Medicine)
From the California Institute of Technology biology professor, Nobel laureate David Baltimore (David Baltimore) led a research team recently found that HIV infected cells to be used close to healthy cells, enabling large quantities of virus spread, which may be HIV After the success of antiretroviral therapy, still a small number of infected cells in the survival reasons. Research papers have been published in the August 17 "Nature" magazine.
Currently, HIV-infected cells in two ways: First, the cell-free spread that virus in plasma to move, hit the immune system cells (T cells) when its transmission; second cell, the viruses in infected for cells as the medium in the cell transmission. Once uninfected target cells, donor cells that put the virus to cells.
Research teams and the use of extracellular HIV infected donor cells to target cells. The lack of donor cells with a natural marker HLA-A2, while the target cells with this symbol, which will help scientists distinguish between two types of cells. The results showed that, regardless of whether the antiviral effect, the target cells will be infected.
The researchers found that cell-free transmission by infected cells in the antiviral effect, the sharp decline in the number, even if the role of drugs in large doses, through cell-cell spread of infected cells is still slowly declining. "We found that cell-cell communication to enable more effects of the virus in a cell," the team member Alex Sigal said, "This makes the virus greatly increased chance of survival." This may explain why antiviral drugs can not eradicate HIV infection. Drug therapy is essentially a probability of anti-virus, that they can not 100% kill the virus. So, when the viral load change for a long time, its survival and risk of infection to the next larger cell.
Another possibility is to enter the incubation period of HIV, the virus lurking in the cells' DNA, gathered into a virus, the role of non-occurrence of replication, which drugs it is invalid. Sigal said that this may affect each other in two ways.
"Determine whether the virus that causes AIDS cell replication of the virus produced, the study treatment is particularly important," he said, "We can not deal with ways to deal with the virus (cell replication)." Theoretically, by activating latent virus in the virus, will enable the eradication of the virus, but if the virus into new cells, they will become difficult to deal with.
"Our next step is, from the physiological level to understand how HIV is transmitted through the cell to infect organs such as lymph nodes," Sigal said. (This article Source: Web of Science Xu Wenjie / compile)
