Zika virus induced cellular remodelling

Zika virus (ZIKV) has been associated with morbidities such as Guillain‐Barré, infant microcephaly, and ocular disease. The spread of this positive‐sense, single‐stranded RNA virus and its growing public health threat underscore gaps in our understanding of basic ZIKV virology. To advance knowledge of the virus replication cycle within mammalian cells, we use serial section 3‐dimensional electron tomography to demonstrate the widespread remodelling of intracellular membranes upon infection with ZIKV. We report extensive structural rearrangements of the endoplasmic reticulum and reveal stages of the ZIKV viral replication cycle. Structures associated with RNA genome replication and virus assembly are observed integrated within the endoplasmic reticulum, and we show viruses in transit through the Golgi apparatus for viral maturation, and subsequent cellular egress. This study characterises in detail the 3‐dimensional ultrastructural organisation of the ZIKV replication cycle stages. Our results show close adherence of the ZIKV replication cycle to the existing flavivirus replication paradigm.     

Andrographolide inhibits influenza A virus-induced inflammation in a murine model through NF-κB and JAK-STAT signaling pathway

Influenza viruses, the main cause of respiratory tract diseases, cause high morbidity and mortality in humans. Excessive inflammation in the lungs is proposed to be a hallmark for the severe influenza virus infection, especially influenza A virus infection. Strategies against inflammation induced by influenza A virus infection could be a potential anti-influenza therapy. Here, lethal dose of mouse-adapted H1N1 strain PR8A/PR/8/34 was inoculated C57BL/6 mice to detect the anti-influenza activity of andrographolide, the active component of traditional Chinese medicinal herb Andrographis paniculata, with or without influenza virus entry inhibitor CL-385319. Treatment was initiated on 4 days after infection. The survival rate, body weight, lung pathology, viral loads, cytokine expression were monitored in 14 days post inoculation. The combination group had the highest survival rate. Andrographolide treatment could increase the survival rate, diminish lung pathology, decrease the virus loads and the inflammatory cytokines expression induced by infection. Mechanism studies showed the NF-κB and JAK-STAT signaling pathway were involved in the activity of andrographolide. In conclusion, combination of virus entry inhibitor with immunomodulator might be a promising therapeutic approach for influenza.     

H5亚型流感病毒HA头部球状结构域在毕赤酵母中的高效表达及其免疫原性分析

为了研究H5亚型流感病毒HA蛋白中头部球状结构的免疫原性及其基因优化对蛋白表达的影响,本研究构建了重组真核表达载体pPICZ?A-H5HA,并将其转化至毕赤酵母,经筛选获得重组菌株。SDS-PAGE和Western blotting结果分析显示,目的蛋白可在酵母中高效分泌表达,发酵液上清中目的蛋白浓度高达0.2 mg/mL,分子量约为37kDa。将酵母发酵上清经浓缩、纯化后,获得重组目的蛋白H5HA。将不同剂量的H5HA与不同佐剂联用后分别以滴鼻和肌肉注射两种方式免疫试验动物,进行免疫效力的评价。试验结果表明,H5HA具有较好的免疫原性,可诱导SPF鸡产生较高水平的IgG (血凝抑制效价达1∶64、病毒中和抗体效价为1∶218),最佳使用剂量为50μg/羽,与白油佐剂联用时效果最佳,且肌肉注射方式的免疫效果优于滴鼻方式。研究结果为H5亚型流感病毒亚单位疫苗的研制提供了理论支撑。     

人类及动物RNA病毒的反向遗传系统

反向遗传系统可以对RNA病毒直接进行遗传操作,为RNA病毒的分子生物学研究提供了一种强大的工具。在过去20年,特别是自90年代中期第一例负链RNA病毒感染性克隆构建成功以来,动物RNA病毒的分子生物学研究取得了长足的进展,这很大程度上归功于各种动物RNA病毒反向遗传系统的建立。这里系统总结了人类及动物非反转录RNA病毒中各类代表性成员在建立反向遗传系统时的方案设计、遇到的困难及研究者如何克服这些困难。分类讨论到的代表性病毒种属有脊髓灰质炎病毒、冠状病毒（包括SARS病毒）、黄病毒、野田村病毒、流感病毒、传染性法氏囊病病毒以及呼肠孤病毒等。     

白纹伊蚊和埃及伊蚊经卵传递登革病毒的研究

白纹伊蚊和埃及伊蚊通过吸食病毒液或叮吸有病毒血症的小鸡血后,能感染登革１－４型病毒,并能在蚊体内增殖,对感染雌蚊了１和子２代幼虫,雌性或雄性成虫４５５９只,分１０１批进行了病毒检测,白纹伊蚊子１代的批阳性率;登革１型为１０％（１／１０）２型为２２．２２％（２／９）３型为３３．３３％（４／１２）,４型为２８．９５％（１１／３８）登革１～４型的最低子代感染率依次主国０．２０％,０．７１％,０．７０％和     

Persistence of MS-2 and PRD-1 bacteriophages in an ultrapure water system

The persistence of bacteriophages MS-2 and PRD-1 was evaluated in tap water, in reverse osmosis (RO) permeate, and in three locations within an ultrapure water system; ultrapure samples included pre- and post-UV sterilization and post-mixed bed ion exchange tank. The inactivation rates for MS-2 were calculated as log₁₀ reduction per hour and per day: k = − (log₁₀ C _t/C _o)/t. PRD-1 was found to persist with no significant loss of infectivity in all water purity environments evaluated. Inactivation of MS-2 was dependent on water quality and pH. Short-term inactivation rates for chlorinated tap water, post-RO, pre-UV, post-UV and post-ion exchange sample locations were 0.028, 0.455, 0.231, 0.191 and 0.168 log₁₀ h⁻¹, respectively. Long-term inactivation rates for chlorinated tap water, post-RO, pre-UV, post-UV and post-ion exchange sample locations were 0.485, 0.911, 0.605, 0.632 and 0.684 log₁₀ day⁻¹, respectively. Since phages were found to remain intact as well as to lyse in the ultrapure water environment, the phages have the potential to contaminate the ultrapure water environments of the microelectronics, pharmaceutical and power generation industries in both colloidal and dissolved form. Further work is proceeding to generate standardized and cost-effective methods to detect viruses in water environments. Received 16 September 1996/ Accepted in revised form 03 January 1997