在一项艾滋病病毒如何变异以应对免疫系统压力的研究中，美国埃默里大学疫苗中心研究人员得出的结论表明，艾滋病病毒能采取若干逃生路线，而不是以一个预定的路线来逃避免疫系统的压力，这意味着单一类型的中和抗体可能不足以遏制艾滋病病毒。此项研究结果发表在9月份的《公共科学图书馆·病原学》（PLoS Pathogens）杂志上。

 

人体免疫系统具有压制早期艾滋病病毒的能力。最近的研究表明，大多数新感染患者都会发展出中和抗体。这些抗体是附着在病毒之上的水滴状血液蛋白，如果它们仅面对一个目标，它们就能允许患者作出自我防御。

 

但问题是，艾滋病病毒具有变异的能力，其掩饰自身的本领足以使其逃避抗体的压力，艾滋病病毒最终会瓦解免疫系统，使其耗竭。

 

埃默里大学研究团队的结果表明，即便研究人员能成功确定一种可刺激中和抗体的疫苗成分，艾滋病病毒快速变异的能力仍是一个令人讨厌的因子。埃默里大学医学院病理学副教授辛西娅·德迪恩称，这些中和抗体的工作虽然非常出色，能够快速并努力地攻击艾滋病病毒，但艾滋病病毒总能想方设法逃脱。这说明，一个单一类型的中和抗体可能不足以遏制艾滋病病毒。

 

德迪恩及其同事参加了由埃默里大学公共卫生学院全球卫生教授苏珊·艾伦领导的一项公共卫生计划，该计划在赞比亚招收了数千对其中一人呈艾滋病病毒阳性的异性夫妇，每3个月为其提供避孕套和相关咨询。尽管采取了这些措施，这些夫妇中仍有低水平的艾滋病病毒传播发生。

 

此次合作使研究团队可在感染发生后，两名参与者免疫系统持续作出反应的数周内即可得到患者的血样。相关研究人员分离出了艾滋病病毒感染的开始两年内的单个病毒，并观察了患者自身的抗体是如何中和这些病毒的。结果表明，在极早期感染的患者中，中和抗体在数周之内即可出现，这比之前人们所认为的要早得多。

 

在两名患者身上，某些病毒会使部分外层蛋白发生变异，变异后一种酶就有可能将一个糖分子附着其上，干扰抗体的攻击。但这种“聚糖盾牌”现象并不能在所有病例中观察到。其他病毒则会使中和抗体直接粘连的部分外层蛋白发生变异。在两名患者中，病毒遗传代码中的许多变化对于其逃脱攻击来说都是必需的。

 

研究人员表示，如果想要搞清楚一个潜在的疫苗中应当有什么，他们就必须了解疫苗反应中的早期事件。此项研究证明，即使在一个患者身上，艾滋病病毒的某些逃脱策略也正在进行中。这意味着，为了免受艾滋病病毒感染，某些患者可能需要准备多种中和抗体。了解这些病毒如何变异，将使研究人员能够在疫苗中选择最佳的药物成分。（来源：科技日报 冯卫东）

Living with HIV using a variety of strategies to evade the immune system
 

 
How the AIDS virus in an immune system in response to the pressure variation of the study, the United States Vaccine Center, Emory University researchers have concluded that HIV can take a number of escape routes, rather than a predetermined route to escape the immune system pressure, which means that a single type of neutralizing antibodies may not be sufficient to contain HIV. The study results were published in September's "PLoS Pathogens" (PLoS Pathogens) magazine.
 
The body's immune system has the ability to suppress the early stage of HIV. Recent studies have shown that most of the new infection will develop neutralizing antibodies. These antibodies are attached to the virus on top of the teardrop-shaped blood protein, if they are only faced with a goal, they can allow the patient to self-defense.
 
But the problem is with a variation of the capacity of HIV and its ability to disguise itself enough to escape the pressure of antibodies, HIV will eventually collapse of the immune system, so depletion.
 
Emory University research team showed that even if researchers can determine the success of a neutralizing antibody may stimulate the vaccine composition, rapid variation in the ability of HIV is still an annoying factor. Emory University School of Medicine Cynthia Yadedien associate professor of pathology, said the work of these neutralizing antibodies, although very well be able to quickly and try to attack the AIDS virus, but HIV can always find ways to escape. This shows that a single type of neutralizing antibodies may not be sufficient to contain HIV.
 
Deen and his colleagues participated in a global health at Emory University School of Public Health, Professor Susan Allen, led a public health program, which plans to recruit thousands of pairs of Zambia, one of whom was HIV-positive heterosexual couples , every 3 months to provide condoms and relevant advice. Despite these measures, these couples there are still a low level of HIV transmission occurs.
 
This co-operation to enable the research team could be after infection, two participants continued to respond to the immune system within a few weeks can be obtained blood samples of patients. Relevant studies have isolated the beginning of the AIDS virus within two years of a single virus, and observed how the patient's own antibodies and in these viruses. The results showed that patients with very early infection, neutralizing antibodies can be within a few weeks to emerge, by people than previously thought to be much earlier.
 
In two patients, certain viruses cause some outer layer of protein is mutated, mutation of an enzyme may be attached to a sugar molecule on which interfere with antibody attack. However, this "glycan shield" phenomenon is not observed in all cases. Other viruses, and antibodies are the direct cause of the outer part of the adhesion proteins mutate. In two patients, the viral genetic code for its many changes are necessary for escape from an attacker.
 
The researchers said that if you want to find out a potential vaccine that should be what, they must understand the immune response in the early event. The study shows that even in a patient body, some of the escape strategy of HIV are underway. This means that, for the avoidance of HIV infection, some patients may need to prepare for a variety of neutralizing antibody. Learn how the variation of these viruses will enable researchers to choose the best vaccine drug ingredients. (Source: Science and Technology Daily Feng Weidong)