hantavirus 发表于 2016-7-25 08:23:51

Science七月精华-病毒类文章汇总

1.Science:阴道微生物组影响HIV感染风险

南非青少年女性有异常高的HIV感染率,而且多年来,科学家们猜测可能存在生物学因子让她们特别容易感染上HIV。2016年在南非德班市举行的世界艾滋病大会(International AIDS Conference)上发布的新研究提出一种可能的罪魁祸首:二路普雷沃尔菌(Prevotella bivia),即一种在阴道中发现的导致炎症的细菌。仔细地研究阴道微生物组发现第二种细菌---加德纳菌(Gardnerella)---可能有助解释为何含有抗HIV药物替诺福韦的杀微生物凝胶不能够保护在临床试验中使用这种凝胶的未感染女性。在试管实验中,加德纳菌“吞食”替诺福韦,快速地降低这种药的含量。

South African teen girls and young women have astonishingly high rates of HIV infection, and researchers for years have suspected that there might be biological factors making them unusually susceptible to infection. New studies presented at the International AIDS Conference being held in Durban, South Africa—located in KwaZulu-Natal province, the hardest hit region in the country—suggest a possible culprit, Prevotella bivia, a bacterium found in the vagina that causes inflammation. The close examination of the vaginal microbiome found a second bacterium,Gardnerella, may help explain why a microbicide gel that contained the anti-HIV drug tenofovir failed to protect many uninfected women who used it in a clinical trial. In test tube experiments,Garnderella "gobbled up" tenofovir, rapidly reducing levels of the drug.

2. Science综述:评论逆转HIV-1潜伏和清除HIV-1

对治愈HIV-1感染的研究需要全球公共卫生在预防和治疗上共同努力。一种根除HIV的主要方法可能需要将抗逆转录病毒抑制、与促进静止期HIV-1基因组的病毒抗原表达的靶向疗法和清除潜伏性HIV-1感染的免疫疗法结合在一起。这些策略旨在根除HIV-1病毒。对这些逆转HIV-1潜伏和清除HIV-1感染的策略组合进行测试已经启动,但是其他的阻止HIV根除的障碍可能会出现。不过,人们也有理由乐观:长期有效的抗逆转录病毒疗法和HIV预防策略取得的进展将推动HIV治愈研究;协同开展这些研究将会显著地降低HIV流行病对社会的影响。

Since the discovery of HIV-1 more than 30 years ago, prevention and treatment strategies have dominated the research agenda. More recently, however, scientists are also focusing their efforts toward finding a cure. Margolis et al. review an approach that involves HIV-1 latency reversal and viral clearance. The idea is to reactivate any dormant virus and coax it to produce viral proteins that the immune system can recognize. By combining a latency reversal strategy with immunotherapies, the body might be able to rid itself of all infected cells.

3. Science:抵抗拉丁美洲发生的寨卡病毒流行病

随着寨卡病毒(Zika virus)感染与小头畸形和其他严重的先天性畸形存在因果关联的证据不断增加,2016年2月,世界卫生组织(WHO)宣布拉丁美洲寨卡病毒流行病是引起国际关注的公共卫生突发事件。这种扩散的速度让有效的公共卫生反应充满挑战。立即采取的应对措施包括传病媒介控制和建议一些国家推迟女性怀孕,随后2016年6月,WHO将提出的一种建议推广到所有受到影响的国家。这些措施有好处,但是也可能只有有限的效果,而且还可能相互抵消。还需要更充分地理解寨卡病毒流行病动态变化和驱动因素来评估这些措施的更长期风险以便优选选择所需的干预措施。

As evidence grew for a causal link between Zika infection and microcephaly and other serious congenital anomalies , the World Health Organization (WHO) declared the Latin American Zika epidemic a public health emergency of international concern in February 2016 . The speed of spread has made effective public health responses challenging. Immediate responses have included vector controland advice to delay pregnancy in a few countries , followed by an extended recommendation to all affected countries by WHO in June 2016. These have merits but are likely to have limited effectivenessand may interact antagonistically. Fuller understanding of dynamics and drivers of the epidemic is needed to assess longer-term risks to prioritize interventions.

4. Science:我国科学家在HIV-1病毒包膜刺突蛋白质的跨膜区结构研究取得进展

国际顶尖学术期刊《科学》Science在线发表了中国科学院上海生命科学研究院生物化学与细胞生物学研究所国家蛋白质科学中心(上海)周界文研究组与哈佛医学院Bing Chen博士研究团队 的合作研究论文“Structural Basis for Membrane Anchoring of HIV-1 Envelope Spike”。该研究采用液体核磁共振技术首次揭示了HIV病毒包膜刺突(HIV-1 Envelope Spike)跨膜区域 的精细三维结构。该研究首次在原子水平上展示了跨膜结构区域是如何锚定、稳定和调控HIV病毒包膜刺突三聚体的分子机理。为针对艾滋病病毒的疫苗设计提供新的思路。

HIV-1包膜刺突(Envelope Spike,Env)是病毒粒子表面上的唯一抗原,是目前疫苗设计的唯一目标。 Env的作用是,通过与宿主细胞受体发生相互作用,帮助病毒进入细胞。成熟的Env,( gp120/gp41)3,是由三个gp120和三个gp41亚单元组成的三聚体。 其中gp41是跨膜蛋白,gp120位于表面,并与gp41通过非共价作用结合。近年来,关于这个包膜刺突的胞外区的结构信息有 很多研究报道,但是关于跨膜区(TM)和它的膜近端区域(包括近外膜区域和胞质尾区),的结构机制还不是很清楚。

在周界文研究员的指导下,利用近期建立的一整套高效的膜蛋白核磁技术,并充分利用国家蛋白质科学研究(上海)设施和哈佛大学的高场核磁共振谱仪,该研究团队在类似磷脂膜的双 分子环境中,首次解析了HIV-1包膜刺突跨膜区域和近膜端区域的高分辨空间结构。结果表明, 跨膜区域形成有序的三聚体结构,保护埋在膜内保守的精氨酸残基。N端卷曲螺旋和C-末端的亲 水核心一起稳定这个三聚体,而后者可以在结构上联接到胞质区尾巴。个别保守残基的突变不能完全破坏TM三聚体,它们对膜融合和病毒的感染的影响非常小。但是,亲水核中的氨基酸突变 ,可以改变成熟Env对抗体的敏感性。该研究首次证实了跨膜区域形成的有序三聚体结构,不仅对Env的膜锚定和膜融合起关键作用,而且对于整个HIV包膜刺突的结构稳定性非常重要。

HIV-1 envelope spike (Env) is a type I membrane protein that mediates viral entry. We used nuclear magnetic resonance to determine an atomic structure of the transmembrane (TM) domain of HIV-1 Env reconstituted in bicelles that mimic a lipid bilayer. The TM forms a well-ordered trimer that protects a conserved membrane-embedded arginine. An amino-terminal coiled-coil and a carboxyl-terminal hydrophilic core stabilize the trimer. Individual mutations of conserved residues did not disrupt the TM trimer and minimally affected membrane fusion and infectivity. Major changes in the hydrophilic core, however, altered the antibody sensitivity of Env. These results show how a TM domain anchors, stabilizes, and modulates a viral envelope spike and suggest that its influence on Env conformation is an important consideration for HIV-1 immunogen design.
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