上海地区人群甲型H1N1流感抗体水平监测分析

Objective To understand levels of antibody to swine-origin influenza A(H1 N1) virus (A/ H1N1) among different age groups in Shanghai, and to compare the levels between antibodies to A/H1N1 and to 2008-2009 seasonal influenza vaccine virus A/Brisbane/59/2007(H1N1). Methods The anti-A/HlN1 antibody levels were determined among 5 age groups (0-5 months, 6 months-4 years, 5-24 years, 25-59 years, and ≥60 years) with routine micro-hemagglutination inhibition test. The positive rates of the antibodies among different age groups were compared by Pearson's X2 test and Fisher' s exact probability test. Results The positive rate of antibody to A/H1N1 in the whole population in Shanghai was 9.2% (37/404). The highest rate was 25.0% (21/84) in the age group of ≥60 years, the next was 10. 0% (8/80) in the age group of 25-59 years, the positive rates in other groups were lower. The result of Pearson's X2 test showed that there were statistically significant differences in the positive rates of the antibodies among different age groups. Of 329 sera positive for antibody to 2008 -2009 seasonal influenza vaccine virus A/Brisbane/59/ 2007 (H1N1), 31 had anti-A/HlNl antibodies, and of 75 sera negative for antibody to A/Brisbane/59/ 2007(H1N1), 6 had anti-A/HlNl antibodies. The result of Pearson's X2 test showed that there were no significant differences in positive rates of antibody to A/H1N1 between the two types of population. Conclusions The anti-A/HlNl levels in Shanghai population are low, and people are generally susceptible to A/H1N1. The sera positive for antibody to A/Brisbane/59/2007(H1N1) can not provide cross-protection against A/H1N1.     

上海地区人群甲型H1N1流感抗体水平监测分析

Objective To understand levels of antibody to swine-origin influenza A(H1 N1) virus (A/ H1N1) among different age groups in Shanghai, and to compare the levels between antibodies to A/H1N1 and to 2008-2009 seasonal influenza vaccine virus A/Brisbane/59/2007(H1N1). Methods The anti-A/HlN1 antibody levels were determined among 5 age groups (0-5 months, 6 months-4 years, 5-24 years, 25-59 years, and ≥60 years) with routine micro-hemagglutination inhibition test. The positive rates of the antibodies among different age groups were compared by Pearson's X2 test and Fisher' s exact probability test. Results The positive rate of antibody to A/H1N1 in the whole population in Shanghai was 9.2% (37/404). The highest rate was 25.0% (21/84) in the age group of ≥60 years, the next was 10. 0% (8/80) in the age group of 25-59 years, the positive rates in other groups were lower. The result of Pearson's X2 test showed that there were statistically significant differences in the positive rates of the antibodies among different age groups. Of 329 sera positive for antibody to 2008 -2009 seasonal influenza vaccine virus A/Brisbane/59/ 2007 (H1N1), 31 had anti-A/HlNl antibodies, and of 75 sera negative for antibody to A/Brisbane/59/ 2007(H1N1), 6 had anti-A/HlNl antibodies. The result of Pearson's X2 test showed that there were no significant differences in positive rates of antibody to A/H1N1 between the two types of population. Conclusions The anti-A/HlNl levels in Shanghai population are low, and people are generally susceptible to A/H1N1. The sera positive for antibody to A/Brisbane/59/2007(H1N1) can not provide cross-protection against A/H1N1.     

Exploring the molecular basis of dsRNA recognition by NS1 protein of influenza A virus using molecular dynamics simulation and free energy calculation

The frequent outbreak of influenza pandemic and the limited available anti-influenza drugs highlight the urgent need for the development of new antiviral drugs. The dsRNA-binding surface of nonstructural protein 1 of influenza A virus (NS1A) is a promising target. The detailed understanding of NS1A–dsRNA interaction will be valuable for structure-based anti-influenza drug discovery. To characterize and explore the key interaction features between dsRNA and NS1A, molecular dynamics simulation combined with MM-GBSA calculations were performed. Based on the MM-GBSA calculations, we find that the intermolecular van der Waals interaction and the nonpolar solvation term provide the main driving force for the binding process. Meanwhile, 17 key residues from NS1A were identified to be responsible for the dsRNA binding. Compared with the wild type NS1A, all the studied mutants S42A, T49A, R38A, R35AR46A have obvious reduced binding free energies with dsRNA reflecting in the reduction of the polar and/or nonpolar interactions. In addition, the structural and energy analysis indicate the mutations have a small effect to the backbone structures but the loss of side chain interactions is responsible for the decrease of the binding affinity. The uncovering of NS1A–dsRNA recognition mechanism will provide some useful insights and new chances for the development of anti-influenza drugs.     

表达甲型H1N1流感病毒血凝素抗原的DNA疫苗构建及其免疫原性评价

目的 构建表达甲型H1N1流感病毒血凝素(hemagglutinin,HA)抗原的DNA疫苗,并在小鼠中测试其免疫原性.方法 运用人密码子优化技术合成甲型H1N1流感病毒HA序列,并转移至DNA疫苗载体,用Western blotting检测其表达效率.采用单纯随机抽样方法把BALB/c小鼠分成DNA疫苗组和对照组.用...     

上海地区在校中学生接种甲型H1N1流感疫苗前后抗体水平监测分析

 目的  了解上海地区在校中学生接种甲型H1N1流感疫苗前后的抗体水平;观察甲型H1N1流感疫苗对该人群的免疫保护作用。 方法    应用常规微量血凝抑制试验（micro-hemagglutination inhibition test, HIT）对上海地区在校中学生分3个时间段进行甲型H1N1流感病毒抗体的血清学监测,3个时间段的抗体阳性率比较采用Pearson χ2 检验进行分析。 结果  2009年甲型H1N1流感流行前上海地区在校中学生的血清抗体阳性率仅为1.3%。经过一段时间流行后,血清抗体阳性率升至8.5%。接种甲型H1N1流感疫苗后,血清抗体阳性率升至87.3%。经Pearson χ² 检验分析,3个时间段在校中学生的血清甲型H1N1流感抗体阳性率差异有统计学意义（χ²=243.7,P<0.05）。 结论  在甲型H1N1流感流行前,上海地区在校中学生对其几乎没有免疫力,接种甲型H1N1流感疫苗能为该人群提供较好的免疫保护作用。     

甲型流感病毒非结构蛋白1抑制干扰素抗病毒反应的研究进展

IFN-α/β是机体对抗外来病原体的第一道防线，其产生和后续激活的细胞信号转导可诱导具有抑制病毒感染和复制作用的IFN刺激基因的表达。然而，大多数病毒可通过表达一种或多种蛋白抵抗宿主细胞的抗病毒反应。流感病毒非结构蛋白1（nonstructural protein 1，NS1）作为多功能毒力因子，在流感病毒感染过程中起重要作用。此文概述了NS1的结构与功能及抑制IFN-α/β产生和抗病毒效应作用的机制，为研究流感病毒致病机理提供参考。     

上海地区人群甲型H1N1流感抗体水平监测分析

目的 了解上海地区不同年龄组人群甲型H1N1流感血清抗体水平,对人群中甲型H1N1与2008-2009年季节性流感疫苗株A/Brisbane/59/2007(H1N1)的血清抗体水平进行分析比较.方法 应用常规微量血凝抑制试验(micro-hemagglutination inhibition test,HI)对上海地区不同年龄组(0～5月龄、6月龄～4岁、5～24岁、25～59岁和≥60岁)人群进行甲型H1N1流感抗体检测.各年龄组抗体阳性率的比较采用Pearson X2检验和Fisher确切概率法进行分析.结果 上海地区人群甲型H1N1流感血清抗体总阳性率为9.2%(37/404).不同年龄组中以老年人组(≥60岁)的血清抗体阳性率最高,为25.0%(21/84);其次是成年人组(25～59岁),血清抗体阳性率为10.0%(8/80);其他年龄组血清抗体阳性率较低.Pearson X2检验结果显示不同年龄组之间抗体阳性率差异有统计学意义.在2008-2009年季节性流感疫苗株A/Brisbane/59/2007(H1N1)抗体阳性的329份血清中有31份甲型H1N1流感抗体阳性,季节性疫苗株抗体阴性的75份血清中有6份甲型H1N1流感抗体阳性.经Pearson X2检验分析,这两层人群甲型H1N1流感抗体阳性率差异没有统计学意义.结论 上海地区人群血清中甲犁H1N1流感抗体水平普遍偏低,其中老年人组抗体水平最高,人群对甲型H1N1流感病毒普遍高度易感;季节性疫苗株A/Brisbane/59/2007(H1N1)HI抗体阳性人群血清不能对甲型H1N1流感病毒产生交叉保护抑制.     

Celgosivir treatment misfolds dengue virus NS1 protein, induces cellular pro-survival genes and protects against lethal challenge mouse model

Dengue virus (DENV) infections continue to spread aggressively around the world. Here we demonstrate that celgosivir (6-O-butanoyl castanospermine), strongly inhibits all four DENV serotypes. We show by fluorescence microscopy that the antiviral mechanism of celgosivir, is in part, due to misfolding and accumulation of DENV non-structural protein 1 (NS1) in the endoplasmic reticulum. Moreover, celgosivir modulates the host’s unfolded protein response (UPR) for its antiviral action. Significantly, celgosivir is effective in lethal challenge mouse models that recapitulate primary or secondary antibody-dependent enhanced DENV infection. Celgosivir treated mice showed enhanced survival, reduced viremia and robust immune response, as reflected by serum cytokine analysis. Importantly, survival increased even after treatment was delayed till 2 days post-infection. Together the present study suggests that celgosivir, which has been clinically determined to be safe in humans, may be a valuable candidate for clinical testing in dengue patients.     

甲型H1N1流感病毒非结构蛋白NS1与人CPSF30结合拮抗剂筛选模型的建立及药物筛选

利用酵母双杂交技术研究甲型H1N1流感病毒非结构蛋白NS1和人切割与多聚腺苷酸化特异因子30 kDa 亚基 (CPSF30) 的相互作用, 构建了一个酵母模型用于筛选NS1和CPSF30相互作用的拮抗剂, 从而为筛选抗甲型H1N1流感病毒药物奠定基础。采用连续重叠PCR技术克隆得到H1N1流感病毒NS1基因。提取人HeLa细胞RNA, 通过RT-PCR克隆得到人CPSF30基因。将NS1基因克隆到表达载体pGBKT7中获得诱饵载体pGBKNS1, 将CPSF30基因克隆到载体pGADT7中获得捕获载体pGADCPSF; 将pGBKNS1和pGADCPSF共转入酿酒酵母AH109, 获得重组酿酒酵母AH109[pGADCPSF+pGBKNS1]。利用该模型筛选了30余种中成药, 发现双黄连口服液等4种中成药能抑制NS1和CPSF30之间的相互作用。     

双黄连片对小鼠流感病毒和腺病毒感染的保护作用

目的观察双黄连片在实验动物体内抗流感病毒和腺病毒的作用,为临床用药提供试验依据。方法建立流感病毒鼠肺适应株FM1感染小鼠模型和腺病毒ADV3株感染小鼠模型,分别灌胃给予高、中、低剂量双黄连片,设立病毒唑对照和正常对照组,观察各组小鼠的死亡数、测定小鼠存活时间、肺指数和肺组织流感病毒滴度。结果双黄连片可明显降低流感病毒和腺病毒感染小鼠的死亡率,延长肺炎小鼠的存活时间,降低肺炎小鼠的肺指数;同时,双黄连片还能降低肺组织中流感病毒的滴度。结论双黄连片在小鼠体内有明显抑制流感病毒和腺病毒的作用。     

贵州省A(H1N1)亚型流感病毒HA基因系列分析

目的:了解贵州省A(H1N1)流感病毒血凝素抗原的基因变异情况.方法:对贵州省分离的部分A(H1N1)流感病毒株利用聚合酶链反应进行扩增,将扩增产物进行序列测定,然后进行基因系列分析.结果:2001-2005年贵州省分离的A(H1N1)流感病毒株有以下位点发生变异:202G>R、203D>N、225R>K、268M>R...     

人用H5N1禽流感病毒疫苗生产工艺的优化

目的 建立优化的人用H5N1禽流感病毒疫苗生产的工艺。方法 在不同的稀释倍数、收获时间及灭活剂添加量下,通过测量收获液的病毒滴度和血凝效价,来确定病毒的最佳生产条件,并对离心法和凝胶过滤层析法的纯化效果进行对比。结果 103~104半数鸡胚感染量(50% egg infective dose,EID50)病毒接种鸡胚,收获的鸡胚尿囊液的病毒滴度和血凝效价最高,分别为10-8.3EID50和1∶480;在56~72 h血凝效价最高。甲醛浓度1∶10 000灭活144 h为灭活最佳条件。两种纯化方法得到的样品纯度和卵清蛋白的去除率相近,但离心纯化法和凝胶过滤层析纯化法病毒回收率有较大的差异,分别为19%和70%。结论 成功建立了高产毒的鸡胚基质H5N1禽流感病毒培养、灭活及纯化工艺。     

Chinese herbal medicine compound Yi-Zhi-Hao pellet inhibits replication of influenza virus infection through activation of heme oxygenase-1

As a leading cause of respiratory disease, influenza A virus (IAV) presents a pandemic threat in annual seasonal outbreaks. Given the limitation of existing anti-influenza therapies, there remains to be a requirement for new drugs. Compound Yi-Zhi-Hao pellet (CYZH) is a famous traditional Chinese medicine (TCM) used in the clinic, whose formula has been recorded in Complication of National Standard for Traditional Chinese Medicine to treat common cold. In this study, we found that CYZH exhibited a broad-spectrum anti-influenza activity and inhibited the expression of viral RNA and proteins in vitro. Mechanistically, CYZH had no inhibitory activities against viral protein hemagglutinin and IAV RNA-dependent RNA polymerase. Instead, it induced activation of erythroid 2-related factor 2 (Nrf2) and nuclear factor kappa B (NF-κB), which subsequently upregulated heme oxygenase-1 (HO-1) expression. Also, CYZH protected cells from oxidative damage induced by reactive oxygen series. In conclusions, CYZH inhibits IAV replication in vitro, at least partly by activating expression of the Nrf2/HO-1 pathway.     

Emodin is a novel alkaline nuclease inhibitor that suppresses herpes simplex virus type 1 yields in cell cultures

Background and purpose:Most antiviral therapies directed against herpes simplex virus (HSV) infections are limited to a small group of nucleoside analogues that target the viral polymerase. Extensive clinical use of these drugs has led to the emergence of resistant viral strains, mainly in immunocompromised patients. This highlights the need for the development of new anti-herpesviral drugs with novel targets. Herein the effects of a plant anthraquinone, emodin, on the HSV-1 alkaline nuclease activity and virus yields were investigated.Experimental approach:HSV-1 alkaline nuclease activity was examined by nuclease activity assay. Inhibition of virus yields was measured by plaque reduction assay and immunohistochemical staining. Interaction between emodin and alkaline nuclease was analysed by docking technology.Key results:Emodin specifically inhibited the nuclease activity of HSV-1 UL12 alkaline nuclease in a biochemical assay. Plaque reduction assay revealed that emodin reduced the plaque formation with an EC(50) of 21.5+/-4.4 muM. Immunohistochemical staining using the anti-nucleocapsid protein antibody demonstrated that emodin induced the accumulation of viral nucleocapsids in the nucleus in a dose-dependent manner. Docking analysis further suggested that the inhibitory effect of emodin on the UL12 activity may result from the interaction between emodin and critical catalytic amino acid residues of UL12.Conclusions and implications:Our findings suggest that emodin is a potent anti-HSV agent that inhibits the yields of HSV-1 via the suppression of a novel target, UL12.British Journal of Pharmacology (2008) 155, 227-235; doi:10.1038/bjp.2008.242; published online 16 June 2008.     

Recruitment of an interferon molecular signaling complex to the mitochondrial membrane: disruption by hepatitis C virus NS3-4A protease

Recent advances in the understanding of the signaling pathways leading to the host antiviral response to hepatitis C virus (HCV), the mechanisms used by HCV to evade the immune response, and the development of small molecule inhibitors of HCV have generated optimism that novel therapeutic approaches to control HCV disease may soon be available. HCV infection is detected by the cytoplasmic, RNA helicase RIG-I that plays an essential role in signaling to the host antiviral response. Recently the adapter molecule that links RIG-I sensing of incoming viral RNA to downstream signaling and gene activation events was characterized by four different groups: MAVS/IPS-1-1/VISA/Cardif contains an amino-terminal CARD domain and carboxyl-terminal mitochondrial transmembrane sequence that localizes to the mitochondrial membrane. Furthermore, the hepatitis C virus NS3-4A protease complex specifically targets MAVS/IPS-1/VISA/Cardif for cleavage as part of its immune evasion strategy. Using a combination of biochemical analysis, subcellular fractionation and confocal microscopy, we demonstrate that: (1) NS3-4A cleavage of MAVS/IPS-1/VISA/Cardif causes relocation from the mitochondrial membrane to the cytosolic fraction, resulting in disruption of signaling to the antiviral immune response; (2) disruption requires a function NS3-4A protease; (3) a point mutant of MAVS/IPS-1/VISA/Cardif (Cys508Ala) is not cleaved from the mitochondria by active protease; and (4) the virus-induced IKK epsilon kinase, but not TBK1, co-localizes strongly with MAVS at the mitochondrial membrane and the localization of both molecules is disrupted by NS3-4A expression. These observations provide an outline of the mechanism by which HCV evades the IFN antiviral response.     

Antiviral activity of the MEK-inhibitor U0126 against pandemic H1N1v and highly pathogenic avian influenza virus in vitro and in vivo

The emergence of the 2009 H1N1 pandemic swine influenza A virus is a good example of how this viral infection can impact health systems around the world in a very short time. The continuous zoonotic circulation and reassortment potential of influenza A viruses (IAV) in nature represents an enormous public health threat to humans. Beside vaccination antivirals are needed to efficiently control spreading of the disease. In the present work we investigated whether the MEK inhibitor U0126, targeting the intracellular Raf/MEK/ERK signaling pathway, is able to suppress propagation of the 2009 pandemic IV H1N1v (v = variant) as well as highly pathogenic avian influenza viruses (HPAIV) in cell culture and also in vivo in the mouse lung. U0126 showed antiviral activity in cell culture against all tested IAV strains including oseltamivir resistant variants. Furthermore, we were able to demonstrate that treatment of mice with U0126 via the aerosol route led to (i) inhibition of MEK activation in the lung (ii) reduction of progeny IAV titers compared to untreated controls (iii) protection of IAV infected mice against a 100× lethal viral challenge. Moreover, no adverse effects of U0126 were found in cell culture or in the mouse. Thus, we conclude that U0126, by inhibiting the cellular target MEK, has an antiviral potential not only in vitro in cell culture, but also in vivo in the mouse model.     

甲型H5N1禽流感病毒血凝素在sf9昆虫细胞中的表达及其鉴定

目的  利用杆状病毒-昆虫细胞表达系统表达甲型H5N1禽流感病毒血凝素（hemagglutinin,HA）并对其进行鉴定。方法  根据sf9昆虫细胞密码子偏好性,对A/Goose/Guangdong/1/96（H5N1）禽流感病毒的HA基因进行序列优化并全长合成。构建重组供体质粒pFastHA,经PCR及测序鉴定后,转化DH10Bac感受态细胞,获得重组穿梭质粒BacmidHA,用M13引物进行PCR鉴定。采用脂质体法转染sf9细胞,获得重组杆状病毒rBacHA。用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法（sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE）、蛋白质印迹法以及间接免疫荧光法对rBacHA表达产物进行分析。结果  供体质粒pFastHA经双酶切后产生了1条与预期大小相符的1 707 bp条带,序列测定证实目的基因无突变。穿梭质粒BacmidHA经PCR扩增,得到1条与预期大小相符的3 180 bp条带。SDS-PAGE结果显示,rBacHA表达产物的相对分子质量约为65 000。蛋白质印迹法分析表明,表达产物能与禽流感病毒阳性血清结合。在荧光显微镜下,感染rBacHA的sf9细胞呈现绿色荧光,提示HA基因得到表达。结论  利用杆状病毒-昆虫细胞表达系统成功制备了具有良好抗原性的重组HA蛋白。     

The 2008-2009 H1N1 influenza virus exhibits reduced susceptibility to antibody inhibition: Implications for the prevalence of oseltamivir resistant variant viruses

A naturally-occurring H275Y oseltamivir resistant variant of influenza A (H1N1) virus emerged in 2007, subsequently becoming prevalent worldwide, via an undetermined mechanism. To understand the antigenic properties of the H275Y variant, oseltamivir resistant and susceptible strains of H1N1 viruses were analyzed by hemagglutination inhibition (HI) and microneutralization assays. HI analysis with H1-positive sera obtained from seasonal flu vaccine immunized and non-immunized individuals, and H1-specific monoclonal antibodies, revealed that resistant strains exhibited a reduced reactivity to these antisera and antibodies in the HI assay, as compared to susceptible strains. Neutralization assay testing demonstrated that oseltamivir resistant H1N1 strains are also less susceptible to antibody inhibition during infection. Mice inoculated with a resistant clinical isolate exhibit 4-fold lower virus-specific antibody titers than mice infected with a susceptible strain under the same conditions. Resistant and sensitive variants of 2009 pandemic H1N1 virus did not exhibit such differences. While HA1 and NA phylogenetic trees show that both oseltamivir resistant and susceptible strains belong to clade 2B, NA D354G and HA A189T substitutions were found exclusively, and universally, in oseltamivir resistant variants. Our results suggest that the reduced susceptibility to antibody inhibition and lesser in vivo immunogenicity of the oseltamivir resistant 2008-2009 H1N1 influenza A virus is conferred by coupled NA and HA mutations, and may contribute to the prevalence of this H1N1 variant.     

Packaging signals in the 5'-ends of influenza virus PA, PB1, and PB2 genes as potential targets to develop nucleic-acid based antiviral molecules

In a previous study a 15-mer phosphorothioate oligonucleotide (S-ON) derived from the packaging signal in the 5′ end of segment 1 (PB2) of influenza A virus (designated 5–15b) proved markedly inhibitory to virus replication. Here we investigated whether analogous inhibitory S-ONs targeting the 5′ end of segments 2 (PB1) and 3 (PA) could be identified and whether viral resistance to S-ONs can be developed. Similar to our earlier result, 20-mer S-ONs reproducing the 5′ ends of segments 2 or 3 (complementary to the 3′-coding regions of PB1 and PA, respectively) exerted a powerful antiviral activity against a variety of influenza A virus subtypes in MDCK cells. Serial passage of the A/Taiwan/1/86 H1N1 strain in the presence of S-ON 5–15b or its antisense as5–15b analogue showed that mutant viruses with reduced susceptibility to the S-ON could indeed be generated, although the resistant viruses displayed reduced replicative fitness. Sequencing the resistant viruses identified mutations in the PB1, PB2, PA and M1 genes. Introduction of these changes into the A/PR/8/34 H1N1 strain by reverse genetics, suggested that alterations to RNA function in the packaging regions of segments 2 and 3 were important in developing resistance to S-ON inhibition. However, many of the other sequence changes induced by S-ON treatment were markedly deleterious to virus fitness. We conclude that packaging signals in the influenza A virus polymerase segments provide feasible targets for nucleic acid-based antivirals that may be difficult for the virus to evade through resistance mutations.     

The route of immunization with adenoviral vaccine influences the recruitment of cytotoxic T lymphocytes in the lung that provide potent protection from influenza A virus

Virus-specific cytotoxic T lymphocytes (CTLs) in the lung are considered to confer protection from respiratory viruses. Several groups demonstrated that the route of priming was likely to have an implication for the trafficking of antigen-specific CTLs. Therefore, we investigated whether the route of immunization with adenoviral vaccine influenced the recruitment of virus-specific CTLs in the lung that should provide potent protection from influenza A virus. Mice were immunized with recombinant adenovirus expressing the matrix (M1) protein of influenza A virus via various immunization routes involving intraperitoneal, intranasal, intramuscular, or intravenous administration as well as subcutaneous administration in the hind hock. We found that the immunization route dramatically impacted the recruitment of M1-specific IFN-γ⁺ CD8⁺ T cells both in the lung and the spleen. Surprisingly, hock immunization was most effective for the accumulation in the lung of IFN-γ-producing CD8⁺ T cells that possessed M1-specific cytolytic activity. Further, antigen-driven IFN-γ⁺ CD8⁺ T cells in the lung, but not in the spleen, were likely to be correlated with the resistance to challenge with influenza A virus. These results may improve our ability to design vaccines that target virus-specific CTL responses to respiratory viruses such as influenza A virus.