关键词： II型疫苗高变异脊髓灰质炎病毒   疫苗衍生脊髓灰质炎病毒的循环   现场流行病学调查  

摘要： 目的对四川省发生的Ⅱ型疫苗高变异脊髓灰质炎(脊灰)病毒/疫苗衍生脊灰病毒(Circulating TypeⅡVaccine Hyperviariable Poliovirus,cVHPVII/TypeⅡVaccine-derived Poliovirus,cVDPVII)的循环事件,进行流行病学调查和分析,为预防控制脊灰和维持无脊灰提供参考。方法对现场流行病学调查和处置等资料进行描述性分析。结果2011年8月～2012年2月,四川省发生了cVHPVII/cVDPVII事件,现场调查、临床诊断、实验室检测结果表明,此次循环事件共发现4例病例,在4例病例和1名密切接触者粪便标本中分离到VHPVⅡ/VDPVⅡ。结论低口服脊灰减毒活疫苗(Oral Poliomye litis Attenuated Live Vaccine,OPV)接种率是此次事件发生的最主要原因。各级卫生部门所采取的包括急性弛缓性麻痹病例主动搜索、OPV应急免疫等多项措施,阻断了cVHPVII/cVDPVII,控制了事件的扩大和蔓延。

关键词： 无血清培养   Vero细胞   脊髓灰质炎病毒  

摘要： 目的探索Vero细胞和脊髓灰质炎病毒在无血清条件下的最佳培养条件,为无血清培养Vero细胞生产脊髓灰质炎疫苗奠定基础。方法选择直接适应(直降组)和序贯适应(驯化组)两种无血清培养方法,观察Vero细胞和脊髓灰质炎病毒在无血清条件下的生长情况,并检测脊髓灰质炎病毒及其病毒滴度。结果 Vero细胞在两种无血清条件下均生长良好,其中驯化组细胞生长速度更接近对照组。以脊髓灰质炎病毒Sabin株Ⅰ型分别感染直降组、驯化组和对照组细胞的病毒滴度平均值分别为8.94、8.81和8.94 LgCCID50/mL;Ⅱ型病毒滴度平均值分别为8.84、8.25和7.94 LgCCID50/mL;Ⅲ型病毒滴度平均值分别为8.91、8.57和8.63 LgCCID50/mL;且3组的变异系数(CV)均小于10%。结论 Vero细胞在无血清条件下生长良好,无血清培养的Vero细胞可用作脊髓灰质炎疫苗生产的基质。

关键词： Dual combinations   SiRMS   Mixture descriptors   Poliovirus  

摘要： We have applied Hierarchical QSAR Technology (HiT QSAR) to the prediction of antiviral effects of paired combinations of picornavirus replication inhibitors against poliovirus 1 (Mahoney) in vitro. The inhibition from all binary combinations of eight antivirals were investigated. Simplex representation of molecular structure (SiRMS) was used for the generation of molecular descriptors of both pure compounds and all dual mixture combinations. Predictive QSAR models were obtained using the partial least squares (PLS) method. Predictive power of the developed models was validated using eightfold external cross-validation (CV, = 0.67-0.93). Adequate models ( = 0.53-0.97) were obtained in the same way for predicting measured inhibitory concentrations at other levels (i.e., IC30, IC40, IC60, IC70). The usage of predicted values of these concentrations in the framework of the feature net (FN) approach led to an insignificant increase in the quality of the obtained QSAR models ( = 0.71-0.94). Developed QSAR models were analyzed and interpreted so that structural fragments and components of the combination promoting the antiviral activity were determined (e.g., 2-(4-methoxyphenyl)-4,5-dihydrooxazole or the combination of N-hydroxybenzimidoyl and 3-methylisoxasole). Then the resulting consensus model was used to predict novel potent combinations of drugs. Combinations of enviroxime with pleconaril, WIN52084, and rupintrivir and the mixture of rupintrivir with disoxaril were predicted to cause the most inhibition of poliovirus 1 replication. HiT QSAR proved itself as an adequate tool for QSAR analysis of mixtures and, although the method described here is suitable only for binary mixtures, it can be easily extended for more complex combinations.

关键词： vaccine-derived poliovirus   poliovirus   circulating VDPV   viruses   Democratic Republic of Congo   DRC  

摘要： Polioviruses isolated from 70 acute flaccid paralysis patients from the Democratic Republic of Congo (DRC) during 2004-2011 were characterized and found to be Vaccine-derived type 2 polioviruses (VDPV2s). Partial genomic sequencing of the isolates revealed nucleotide sequence divergence of up to 3.5% in the viral protein 1 capsid region of the viral genome relative to the Sabin vaccine strain. Genetic analysis identified at least 7 circulating lineages localized to specific geographic regions. Multiple independent events of VDPV2 emergence occurred throughout DRC during this 7-year period. During 2010-2011, VDPV2 circulation in eastern DRC occurred in an area distinct from that of wild poliovirus circulation, whereas VDPV2 circulation in the southwestern part of DRC (in Kasai Occidental) occurred within the larger region of wild poliovirus circulation.

关键词： Lipoprotein   Liposomes   Membrane Bilayer   Membrane Biophysics   Membrane Reconstitution   Positive-strand RNA Viruses   Viral Protein   Viral Replication  

摘要： Infection with many positive-strand RNA viruses dramatically remodels cellular membranes, resulting in the accumulation of double-membraned vesicles that resemble cellular autophagosomes. In this study, a single protein encoded by poliovirus, 3AB, is shown to be sufficient to induce the formation of double-membraned liposomes via the invagination of single-membraned liposomes. Poliovirus 3AB is a 109-amino acid protein with a natively unstructured N-terminal domain. HeLa cells transduced with 3AB protein displayed intracellular membrane disruption;specifically, the formation of cytoplasmic invaginations. The ability of a single viral protein to produce structures of similar topology to cellular autophagosomes should facilitate the understanding of both cellular and viral mechanisms for membrane remodeling.

关键词： Research Article  

摘要： Poliovirus protease 2A (2A(pro)) obstructs host gene expression by reprogramming transcriptional and post-transcriptional regulatory events during infection. Here we demonstrate that expression of 2A(pro) induces a selective nucleo-cytoplasm translocation of several important RNA binding proteins and splicing factors. Subcellular fractionation studies, together with immunofluorescence microscopy revealed an asymmetric distribution of HuR and TIA1/TIAR in 2A(pro) expressing cells, which modulates splicing of the human Fas exon 6. Consistent with this result, knockdown of HuR or overexpression of TIA1/TIAR, leads to Fas exon 6 inclusion in 2A(pro)-expressing cells. Therefore, poliovirus 2A(pro) can target alternative pre-mRNA splicing by regulating protein shuttling between the nucleus and the cytoplasm.

关键词： 脊髓灰质炎病毒   脊灰减毒活疫苗   脊灰疫苗衍生病毒   急性弛缓性麻痹  

摘要： 目的阐述湖北省1例脊髓灰质炎(脊灰)疫苗高变异株病例的流行病学调查与处理情况。方法对疫情开展病例个案调查、实验室检测、病毒传播风险评估,对病例进行消毒、随访,由省级AFP病例专家诊断小组会诊并做出临床分类。结果 2013年5月,湖北省发生1例Ⅲ型脊灰疫苗高变异株病毒病例,经省级和国家脊灰实验室在对病例所分离到的脊灰病毒进行核苷酸序列测定时,与Sabin疫苗株比较发现VP1区有8个(0.88%)核苷酸变异。患儿总共口服了2剂次脊灰减毒活疫苗(oral poliomyelitis vaccine,OPV),未规范服苗。结论该病例最终分类诊断为非AFP病例。各级卫生部门采取了包括主动搜索急性弛缓性麻痹(acute flaccid paralysis,AFP)病例、开展查漏补种OPV等措施,有效控制了疫情的扩大和蔓延。

关键词： Picornavirus   Poliovirus   Stress granules   SRp20   TIA-1   Protein co-localization  

摘要： Different types of environmental stress cause mammalian cells to form cytoplasmic foci, termed stress granules, which contain mRNPs that are translationally silenced. These foci are transient and dynamic, and contain components of the cellular translation machinery as well as certain mRNAs and RNA binding proteins. Stress granules are known to be induced by conditions such as hypoxia, nutrient deprivation, and oxidative stress, and a number of cellular factors have been identified that are commonly associated with these foci. More recently it was discovered that poliovirus infection also induces the formation of stress granules, although these cytoplasmic foci appear to be somewhat compositionally unique. Work described here examined the punctate pattern of SRp20 (a host cell mRNA splicing protein) localization in the cytoplasm of poliovirus-infected cells, demonstrating the partial co-localization of SRp20 with the stress granule marker protein TIA-1. We determined that SRp20 does not co-localize with TIA-1, however, under conditions of oxidative stress, indicating that the close association of these two proteins during poliovirus infection is not representative of a general response to cellular stress. We confirmed that the expression of a dominant negative version of TIA-1 (TIA-1-PRD) results in the dissociation of stress granules. Finally, we demonstrated that expression of wild type TIA-1 or dominant negative TIA-1-PRD in cells during poliovirus infection does not dramatically affect viral translation. Taken together, these studies provide a new example of the unique cytoplasmic foci that form during poliovirus infection. (C) 2013 Elsevier B.V. All rights reserved.

关键词： Antiviral   Caesalpinia ferrea   Sulfated polysaccharide   Herpesvirus   Poliovirus  

摘要： Herpes simplex virus (HSV) is one of the most regular human pathogens, being a public health problem, and causal agent of several diseases. Poliovirus (PV) is an enteric virus and about 1% of infected individuals develop paralytic poliomyelitis due to viral invasion of the central nervous system and destruction of motor neurons. This work evaluated the activity of a sulfated polysaccharide of Caesalpinia ferrea (SPLCf) in HSV and PV replication. The antiviral effect of SPLCf at varying concentrations was tested by plague assay under several protocols, such as time-of-addition, adsorption and penetration inhibition and virucidal. Syntheses of viral protein and nucleic acid were also monitored by the immunofluorescence assay and PCR. The SPLCf inhibited virus adsorption and steps after penetration, and inhibited the synthesis of viral protein. Virucidal effect was also shown and nucleic acid synthesis was concurrent with positive results. Our findings suggested that the substance with low toxicity represent a potential viral inhibitor. (C) 2013 Elsevier B.V. All rights reserved.

关键词： ENTEROVIRUSES   IMMUNE response   CD4 antigen   CROSS reactions (Immunology)   COXSACKIEVIRUSES   POLIOVIRUS  

摘要： Enterovirus 71 (EV71)-associated hand-foot-mouth disease has become a major threat to public health in the Asia-Pacific region. Although T cell immunity is closely correlated with clinical outcomes of EV71 infection, little is known about T cell immunity baseline against EV71 and T cell immunogenecity of EV71 Ags in the population, which has restricted our understanding of immunoprotection mechanisms. In this study, we investigated the cellular immune responses against the four structural Ags of EV71 and determined the immunohierarchy of these Ags in healthy adults. A low frequency of EV71-responsive T cells was detected circulating in peripheral blood, and broad T cell immune responses could be identified in most of the subjects after in vitro expansion. We demonstrated that the VP2 Ag with broad distribution of immunogenic peptides dominates T cell responses against EV71 compared with VP1, VP3, and VP4. Furthermore, the responses were illuminated to be mainly single IFN-gamma-secreting CD4(+) T cell dependent, indicating the previous natural acute viral infection of the adult population. Conservancy analysis of the immunogenic peptides revealed that moderately variant peptides were in the majority in coxsackievirus A16 (CV-A16) whereas most of the peptides were highly variant in polioviruses. Less efficient cross-reactivity against CV-A16 might broadly exist among individuals, whereas influences derived from poliovirus vaccination would be limited. Our findings suggest that the significance of VP2 Ag should be addressed in the future EV71-responsive immunological investigations. And the findings concerning the less efficient cross-reactivity against CV-A16 and limited influences from poliovirus vaccination in EV71-contacted population would contribute to a better understanding of immunoprotection mechanisms against enteroviruses.