EV71的感染和抗病毒天然免疫应答

EV71是儿童手足口病的主要病原体,部分感染儿童会出现疱疹性咽峡炎以及严重的肺水肿和/或脑干脑炎。近几年,EV71感染引起的疾病机制研究取得了诸多进展。本文针对目前EV71的敏感细胞、EV71感染激活的信号途径以及EV71感染活化的天然免疫应答或免疫逃逸机制研究进行综述,旨在为EV71抗病毒药物研制和免疫致病机理的研究提供思路。     

ICAM-1K469E 位点A 等位基因可降低EV71 手足口病发生率

目的:研究ICAM-1基因K469E位点、MCP-1A2518G位点基因多态性及sICAM-1、MCP-1在血清中表达水平与EV71手足口病的关系,探讨EV71型手足口病的遗传易感因素。方法:运用限制性片段长度多态性-聚合酶链反应(PCR-RFLP)检测急性期EV71感染阳性的手足口病患儿和正常儿童中ICAM-1K469E位点及MCP-1A2518G位点碱基变异情况,同时采用双夹心抗体法(ELISA)检测血清sICAM-l和MCP-1水平。结果:EV71手足口病组患儿血清中sICAM-l和MCP-1水平均显著高于正常对照组(P均<0.01)。EV71手足口病组ICAM-1K469E位点中,A等位基因的频率显著低于对照组(x2=6.897,P<0.01)。EV71手足口病组患儿MCP-1基因型分布、等位基因频率与对照组比较均无统计学意义(P>0.05)。结论:sICAM-1表达水平和其基因K469E位点多态性与EV71手足口病有关,A等位基因可降低EV71手足口病发生率。MCP-1表达水平与EV71手足口病感染有关,但MCP-1A-2518G位点基因多态性与EV71手足口病感染无关。     

肠道病毒71型2A蛋白的研究进展

肠道病毒71(enterovirus 71,EV71)是手足口病(hand,foot and mouth disease,HFMD)主要致病原之一。手足口病临床上常表现为发热,手掌、脚掌及口腔黏膜皮疹或疱疹。然而,EV71感染导致的手足口病易伴随神经系统并发症,甚至死亡。EV71非结构蛋白2A作为蛋白酶和转录激活因子,在EV71生命周期中发挥重要作用。本文对2A的结构与功能研究进展进行综述,揭示2A的双重功能如何促进病毒复制和调控靶细胞,为进一步研究靶向2A的抗病毒疫苗和药物提供理论基础。     

肠道病毒71型致神经源性肺水肿发病机制研究进展

肠道病毒71型(EV71)是人类肠道病毒的一种,近30年来,EV71感染在亚太地区广泛流行,是手足口病重症病例的主要病原体之一.EV71感染最严重的并发症为中枢神经系统和呼吸系统受累,其中神经源性肺水肿病程进展迅速、治疗困难、病死率高,近年来受到人们的广泛关注,但其发病机制目前尚不十分清楚.本研究对EV71感染导致的神经源性肺水肿的发病机制从脑干脑炎、全身炎症反应及免疫等方面的研究进展作一综述.     

肠道病毒71型实验室诊断研究进展

肠道病毒71型(Enterovirus 71,EV71)为手足口病(Handf,oot and mouth disease,HFMD)和相关疾病的主要病原体,多感染婴幼儿,少数病例可以并发呼吸道感染和心肌炎、无菌性脑膜炎、脑炎、急性弛缓性麻痹等严重疾病,可致残、致死。因此EV71实验室诊断对EV71引起疾病的治疗和防控具有重要意义。本文将从核酸检测、抗体检测及其他检测等三部分对EV71的实验室诊断方法研究进展进行了综述。     

人肠道病毒71型与手足口病的分子流行病学及其分子进化

人肠道病毒71血清型(Enterovirus 71, EV71)是手足口病(Hand, foot and mouth disease, HFMD)的主要病原体之一,除了引起手、足和口腔等部位出现疱疹的手足口病典型症状,还能引起无菌性脑膜炎和急性迟缓性麻痹等神经系统并发症并致死亡。EV71在历史上曾经造成多起手足口病疫情,尤其是1997年之后,在亚太地区发生了大规模的手足口病疫情,造成了大量的手足口病病例和死亡病例。手足口病尚无上市疫苗和抗病毒药物,主要依赖对症治疗,因此对EV71的分子流行病学和分子进化研究对手足口病的监测和防控具有重要意义。文章对EV71基因型的分类、时空分布、进化特征和模式以及所造成的代表性疫情进行了综述,为EV71致病机制、抗病毒药物和疫苗的研究以及对手足口病疫情的监测和防控提供启发。     

抗肠道病毒71型的药物研究进展

肠道病毒71型（Enterovirus 71,EV71）是引起重症手足口病（Hand,Foot and Mouth Disease,HFMD）的主要病原体。重症HFMD进展迅速,可表现为严重的神经系统并发症,甚至危及生命。目前临床上防治EV71感染缺乏特异、高效的药物,其残疾率和死亡率很高。随着研究的深入,已经发现了大量具有抗EV71能力的化合物,人们探索的药物机制和药物靶点各不相同。因此,本文从药物靶向病毒、宿主等角度出发,针对抗EV71感染的天然药物、合成药物及常见中药中活性成分作用机制的最新进展进行综述与讨论。此外,对抗病毒药物筛选技术进行简要概述,以期为抗EV71药物的筛选与研发设计等相关研究提供参考。     

肠道病毒71型分子流行病学研究进展

肠道病毒71型(Enterovirus type71,EV71),自1974年首次报道以来,在世界范围内引起多次爆发与流行[1].EV71感染主要引起患者手足口病(hand,foot and mouth disease,HFMD),在临床上与柯萨奇病毒A16(Coxsakie A16,CA16)感染所引起的手足口病难以区别,但EV71还能够引起多种与神经系统相关的疾病[2].近年来,EV71病毒的流行在亚太地区呈上升趋势[3～5],其中最令人关注的是在该地区的EV71感染引起越来越严重的中枢神经系统症状.     

肠病毒71交叉中和性表位的识别与鉴定

<正>在儿童中的肠病毒71(EV71)感染是作为疹病而出现的并被称为手足口病(HFMD)。由于它能引起严重的类似脊灰的神经性并发症,EV71目前在亚洲是一种新出现的重要的嗜神经病毒。EV71有3种基因型(A、B和C)以及许多亚基因型,虽然     

肠道病毒71型与天然免疫系统相互作用的研究进展

肠道病毒71型(enterovirus 71,EV71)为小RNA病毒科肠道病毒属成员,是引起手足口病的主要病原体之一。EV71流行广泛,其感染可引发中枢神经系统疾病,并造成重症手足口病,给公共卫生安全带来极大挑战。EV71的致病机制与病毒和宿主天然免疫系统的相互作用关系密切,涉及病毒逃逸干扰素反应、病毒抑制核因子κB(nuclear factorκB,NF-κB)信号通路及病毒与天然免疫细胞相互作用等多个环节。本文就近年来EV71与宿主天然免疫系统相互作用的研究进展进行综述。     

Enterovirus71 (EV71) Utilise Host microRNAs to Mediate Host Immune System Enhancing Survival during Infection

Hand, Foot and Mouth Disease (HFMD) is a self-limiting viral disease that mainly affects infants and children. In contrast with other HFMD causing enteroviruses, Enterovirus71 (EV71) has commonly been associated with severe clinical manifestation leading to death. Currently, due to a lack in understanding of EV71 pathogenesis, there is no antiviral therapeutics for the treatment of HFMD patients. Therefore the need to better understand the mechanism of EV71 pathogenesis is warranted. We have previously reported a human colorectal adenocarcinoma cell line (HT29) based model to study the pathogenesis of EV71. Using this system, we showed that knockdown of DGCR8, an essential cofactor for microRNAs biogenesis resulted in a reduction of EV71 replication. We also demonstrated that there are miRNAs changes during EV71 pathogenesis and EV71 utilise host miRNAs to attenuate antiviral pathways during infection. Together, data from this study provide critical information on the role of miRNAs during EV71 infection.     

Antiviral effects of two Ganoderma lucidum triterpenoids against enterovirus 71 infection

Enterovirus 71 (EV71) is a major causative agent for hand, foot and mouth disease (HFMD), and fatal neurological and systemic complications in children. However, there is currently no clinical approved antiviral drug available for the prevention and treatment of the viral infection. Here, we evaluated the antiviral activities of two Ganoderma lucidum triterpenoids (GLTs), Lanosta-7,9(11),24-trien-3-one,15;26-dihydroxy (GLTA) and Ganoderic acid Y (GLTB), against EV71 infection. The results showed that the two natural compounds display significant anti-EV71 activities without cytotoxicity in human rhabdomyosarcoma (RD) cells as evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell proliferation assay. The mechanisms by which the two compounds affect EV71 infection were further elucidated by three action modes using Ribavirin, a common antiviral drug, as a positive control. The results suggested that GLTA and GLTB prevent EV71 infection through interacting with the viral particle to block the adsorption of virus to the cells. In addition, the interactions between EV71 virion and the compounds were predicated by computer molecular docking, which illustrated that GLTA and GLTB may bind to the viral capsid protein at a hydrophobic pocket (F site), and thus may block uncoating of EV71. Moreover, we demonstrated that GLTA and GLTB significantly inhibit the replication of the viral RNA (vRNA) of EV71 replication through blocking EV71 uncoating. Thus, GLTA and GLTB may represent two potential therapeutic agents to control and treat EV71 infection.     

Antiviral activity of GuiQi polysaccharides against enterovirus 71 in vitro

In this study, we have investigated the antiviral activity of GuiQi polysaccharides（GQP） upon enterovirus 71 （EV71） in vitro. An assay using methyl thiazolyl tetrazolium（MTT）, and analyses of cytopathic effects（CPE） were used to examine the antiviral activity of GQP upon Vero cells infected with EV71. The results revealed that GQP at concentrations below 31.2 μg/mL exhibited significant antiviral effects upon EV71 when applied under three different experimental protocols. GQP was most strongly active in preventing the adsorption of EV71 to target cells and in this respect it was significantly more effective than ribavirin. In addition, it was clear that GQP could inhibit viral replication when added to cells 2 h after infection, but if added at the point of infection its effect was weak. GQP is considered to be less toxic than ribavirin, and may warrant further evaluation as a possible agent in the treatment of hand, foot and mouth disease（HFMD）.     

Characterization of an outbreak of hand, foot, and mouth disease in Nanchang, China in 2010

Recent outbreaks of human enterovirus 71 (EV71) infection and EV71-associated hand, foot, and mouth disease (HFMD) in China have affected millions and potentially lead to life-threatening complications in newborns. Furthermore, these outbreaks represent a significant global public health issue in the world. Understanding the epidemiology of HFMD and EV71 infection and their transmission patterns in China is essential for controlling outbreaks. However, no studies on the outbreaks of HFMD and EV71 infection in China during 2010 have been reported. In this report, we carried out an epidemiological analysis to study an outbreak of HFMD and EV71 infection in 2010 in the city of Nanchang in the Jiangxi province of People's Republic of China. From April 7 to May 11, 2010, a total of 109 HFMD cases were reported, and in this report the HFMD cases were studied by both epidemiological and laboratory analyses. The epidemiological study indicates that children aged younger than 8 years old represented more than 90% of the reported cases, with the age group of 1-3 years containing the highest number of cases. Laboratory studies detected a high prevalence of EV71 amongst the cases in our study, suggesting EV71 as a common enterovirus found in HFMD cases in Nanchang. Phylogenetic analysis of the sequence of the VP1 region of four EV71 isolates indicated that the Nanchang strains belong to the C4 subgenotype commonly found in China during outbreaks in 2008 but contain distinct variations from these strains. Our study for the first time characterizes the epidemiology of HFMD and EV71 infection in China in 2010 and furthermore, provides the first direct evidence of the genotype of EV71 circulating in Nanchang, China. Our study should facilitate the development of public health measures for the control and prevention of HFMD and EV71 infection in at-risk individuals in China.     

Clinical Efficacy of Therapy with Recombinant Human Interferon α1b in Hand,Foot, and Mouth Disease with Enterovirus 71 Infection

A rapid expansion of HFMD with enterovirus 71 infection outbreaks has occurred and caused deaths in recent years in China, but no vaccine or antiviral drug is currently available for EV71 infection. This study aims to provide treatment programs for HFMD patients. We conducted a randomized, double-blind, controlled trial and evaluated clinical efficacy of therapy with rHuIFN-α1b in HFMD patients with EV71 infection. There were statistical differences in outcomes including the fever clearance time, healing time of typical skin or oral mucosa lesions, and EV71 viral load of the HFMD patients among ultrasonic aerosol inhalation group, intramuscular injection group and control group. rHuIFN-α1b therapy reduced the fever clearance time, healing time of typical skin or oral mucosa lesions, and EV71 viral load in children with HFMD.Trial Registration: Chinese Clinical Trial Registry ChiCTR-TRC-14005153     

An overview of the evolution of enterovirus 71 and its clinical and public health significance

Since its discovery in 1969, enterovirus 71 (EV71) has been recognised as a frequent cause of epidemics of hand-foot-and-mouth disease (HFMD) associated with severe neurological sequelae in a small proportion of cases. There has been a significant increase in EV71 epidemic activity throughout the Asia-Pacific region since 1997. Recent HFMD epidemics in this region have been associated with a severe form of brainstem encephalitis associated with pulmonary oedema and high case-fatality rates. The emergence of large-scale epidemic activity in the Asia-Pacific region has been associated with the circulation of three genetic lineages that appear to be undergoing rapid evolutionary change. Two of these lineages (B3 and B4) have not been described previously and appear to have arisen from an endemic focus in equatorial Asia, which has served as a source of virus for HFMD epidemics in Malaysia, Singapore and Australia. The third lineage (C2) has previously been identified [Brown, B.A. et al. (1999) J. Virol. 73, 9969-9975] and was primarily responsible for the large HFMD epidemic in Taiwan during 1998. As EV71 appears not to be susceptible to newly developed antiviral agents and a vaccine is not currently available, control of EV71 epidemics through high-level surveillance and public health intervention needs to be maintained and extended throughout the Asia-Pacific region. Future research should focus on (1) understanding the molecular genetics of EV71 virulence, (2) identification of the receptor(s) for EV71, (3) development of antiviral agents to ameliorate the severity of neurological disease and (4) vaccine development to control epidemics. Following the successful experience of the poliomyelitis control programme, it may be possible to control EV71 epidemics if an effective live-attenuated vaccine is developed.     

Recent Progress on Functional Genomics Research of Enterovirus 71

Enterovirus 71(EV71) is one of the main pathogens that causes hand-foot-and-mouth disease(HFMD). HFMD caused by EV71 infection is mostly self-limited; however, some infections can cause severe neurological diseases, such as aseptic meningitis, brain stem encephalitis, and even death. There are still no effective clinical drugs used for the prevention and treatment of HFMD. Studying EV71 protein function is essential for elucidating the EV71 replication process and developing anti-EV71 drugs and vaccines. In this review, we summarized the recent progress in the studies of EV71 noncoding regions(50 UTR and 30 UTR) and all structural and nonstructural proteins, especially the key motifs involving in viral infection, replication, and immune regulation. This review will promote our understanding of EV71 virus replication and pathogenesis, and will facilitate the development of novel drugs or vaccines to treat EV71.     

Preclinical Evaluation of the Immunogenicity and Safety of an Inactivated Enterovirus 71 Candidate Vaccine

Human enterovirus 71 (EV71) is a significant cause of morbidity and mortality from Hand, Foot and Mouth Disease (HFMD) and neurological complications, particularly in young children in the Asia-Pacific region. There are no vaccines or antiviral therapies currently available for prevention or treatment of HFMD caused by EV71. Therefore, the development of therapeutic and preventive strategies against HFMD is of growing importance. We report the immunogenic and safety profile of inactivated, purified EV71 preparations formulated with aluminum hydroxide adjuvant in preclinical studies in mice and rabbits. In mice, the candidate vaccine formulations elicited high neutralizing antibody responses. A toxicology study of the vaccine formulations planned for human use performed in rabbits showed no vaccine-related pathological changes and all animals remained healthy. Based on these preclinical studies, Phase 1 clinical testing of the EV71 inactivated vaccine was initiated.     

Virucidal activity and the antiviral mechanism of acidic polysaccharides against Enterovirus 71 infection in vitro

Enterovirus 71 (EV71) is the predominant pathogen for severe hand, foot, and mouth disease (HFMD) in children younger than 5 years, and currently no effective drugs are available for EV71. Thus, there is an urgent need to develop new drugs for the control of EV71 infection. In this study, LJ04 was extracted from Laminaria japonica using diethylaminoethyl cellulose-52 with 0.4 mol/l NaCl as the eluent, and its virucidal activity was evaluated based on its cytopathic effects on a microplate. LJ04 is composed of fucose, galactose, and mannose and mainly showed good virucidal activity against EV71. The antiviral mechanisms of LJ04 were the direct inactivation of the virus, the blockage of virus binding, disruptions to viral entry, and weak inhibitory activity against the nonstructural protein 3C. The two most important findings from this study were that LJ04 inhibited EV71 proliferation in HM1900 cells, which are a human microglia cell line, and that LJ04 can directly inactivate EV71 within 2 hr at 37°C. This study demonstrates for the first time the ability of a polysaccharide from L. japonica to inhibit viral and 3C activity; importantly, the inhibition of 3C might have a minor effect on the antiviral effect of LJ04. Consequently, our results identify LJ04 as a potential drug candidate for the control of severe EV71 infection in clinical settings.     

Differential interferon pathway gene expression patterns in Rhabdomyosarcoma cells during Enterovirus 71 or Coxsackievirus A16 infection

Exposure of cells to type I interferon (IFN) induces an antiviral state that prevents viral infection, but viruses can utilize multiple tactics to antagonize the host immune system. Enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16) are two major pathogens that cause hand, foot, and mouth disease (HFMD), which is prevalent among children. We found that both EV71 and CA16 have different reactions to type I IFN pretreatment and induction patterns of type I IFN on Rhabdomyosarcoma (RD) cells. Further, a human-α and β IFN PCR array was employed to analyze the expressions of 84 genes related to the type I IFN pathway. We found significant up-regulation of multiple genes in the presence of type I IFN and differential regulation patterns during EV71 or CA16 infection in RD cells. For instance, EV71 infection repressed the JAK-STAT signaling pathway and interferon-stimulated gene (ISG) expression, whereas CA16 infection normally triggers the JAK-STAT pathway, leading to the expression of ISGs. Taken together, this study provides a comprehensive view of the differential impacts of EV71 and CA16 infection on 84 genes in the IFN pathway, shedding light on the different resistances of these viruses to type I IFN treatment and cytotoxic effects in RD cells.