利用恒河婴猴模型对肠道病毒71型传播感染特征的生物学分析

本文在前期工作基础上,进一步对肠道病毒71型(EV71)从恒河婴猴的感染个体向其他未感染个体传播的可能性及相关生物学特性做了初步分析.通过喷雾形式经呼吸道感染1~2月龄恒河婴猴(A组);在观察临床症状同时,于感染后第7天,取该组动物粪便处理后,将上清液以喷雾形式经呼吸道感染新的婴猴个体(B组),随后对该次代感染个体进行...     

EV71灭活疫苗（人二倍体细胞）在恒河猴婴猴模型中的免疫保护性分析

肠道病毒71型作为引起儿童群体常见传染性手足口病（HFMD）的主要病原,具有导致少量感染个体出现脑炎等神经系统病变以及相关心肺功能衰竭的病理学特性．因此其预防性疫苗的研发具有重要的公共卫生意义．在前期工作的基础上,一种EV71灭活病毒疫苗（人二倍体细胞）在本研究中基于恒河猴婴猴模型进行了相应的免疫保护性分析．以160EU剂量对2～3月龄婴猴进行0,4周免疫后,动物在第4周接受了剂量为10。～CCID50的病毒经呼吸道的攻击．对病毒攻击后动物在14天内的临床症状、血液生物学、器官病原学分布以及病理学检测的动态观察表明,经疫苗免疫的动物未出现对照动物所具有的特征性临床表现,其血液生物学及病理学检测均无异常．同时,器官病原学分布亦呈阴性．结合动物中和抗体的明确增长及对照动物的综合表现分析,本文的工作证实了该EV71灭活病毒疫苗（人二倍体细胞）在恒河猴婴猴体内的免疫保护性．     

肠道病毒71型感染动物模型的应用与局限

肠道病毒71型(enterovirus 71,EV71)是一种被忽视的热带传染病——手足口病的主要病原体之一,过去15年在亚太地区引起了多次手足口病暴发。由于脊髓灰质炎病毒的有效控制,EV71已成为最重要的嗜神经肠道病毒,其严重的神经系统并发症威胁着儿童健康。合适的动物模型可帮助更好地了解EV71神经致病机制,并有利于开发有效的疫苗和治疗药物。本文就EV71已建立的3类主要动物模型(非人灵长类动物模型、小鼠适应性模型及转基因小鼠模型)的特征、应用与局限进行综述。     

肠道病毒71型感染机制研究进展

重症手足口病及其死亡病例多由肠道病毒71型(Enterovirus A71,EV-A71)感染引起,且近年来在亚太地区广泛流行。由于EV-A71具有严格的宿主细胞寄生性,需依赖细胞的能量和代谢系统完成其复制过程。因此研究该病毒在进入、脱衣壳等感染早期过程中病毒与宿主相互作用的机制,不仅有助于理解其致病机理,同时可为建立相应预防和治疗的策略提供科学依据。为此,就EV-A71感染早期的致病机制的研究进展进行了综述。     

肠道病毒71型(EV-A71)感染ICR小鼠模型的建立

为研究肠道病毒71型(Enterovirus 71,EV-A71)经不同攻毒方式感染不同日龄ICR乳鼠的感染情况,了解EV-A71在小鼠体内的动态分布和感染机制,为建立EV-A71感染动物模型,本研究采用分离自重症手足口患儿的EV-A71毒株,分别通过肌肉注射(Intramuscular injection,IM)、腹腔注射(Intraperitoneal injection,IP)以及脑内注射(Intracerebral injection,IC)的方式感染3日、5日和9日龄ICR乳鼠,感染后定期采集血液和各组织,通过Realtime PCR追踪各组织中病毒载量变化,并且通过切片制作和免疫组化对感染乳鼠进行病原学和病理学分析。结果显示:对于低日龄(≤5日龄)乳鼠,注射剂量在104.5 TCID50/g·体重时IM、IP及IC均为较好的感染方式,都会出现神经症状,且有极高的致死率。随着日龄增长,感染后症状有所减轻,但IM和IP感染途径对大日龄乳鼠仍具有良好的致病性,且IM和IP死亡率显著高于IC死亡率。经IM、IP和IC注射感染病毒的3日龄乳鼠在6dpi体重相对于各对照组分别下降了1.54g(31.43%)、1.31g(15.06%)和2.52g(44.28%),而经IM和IP感染的5日龄乳鼠6dpi体重相对于各对照组分别下降了0.605g(8.95%)、0.886g(15.51%),经IC感染的5日龄乳鼠6dpi体重相对于对照组上升了0.904g(14.70%),感染组体重均显著低于对应的同期对照组(P0.05)。经IM、IP和IC感染病毒的3日龄乳鼠9dpi均死亡,而5日龄乳鼠9dpi存活率分别为42.8%、25%和87.5,14dpi存活率分别为0%、0%和25%,9日龄乳鼠9dpi存活率分别为70%、84.62%和100%。病理学及免疫组化检查显示EV-A71病毒具有强烈的嗜神经性及嗜骨骼肌的特性,可导致病毒血症、脑神经元及骨骼肌坏死、心肌间质水肿及多脏器炎症反应。我们系统地研究了不同攻毒方式感染不同日龄的ICR乳鼠后的病毒动态分布及免疫病理损伤,发现经肌肉注射或腹腔注射5日龄乳鼠能够建立理想的EV-A71感染动物模型。     

肠道病毒71型及其疫苗的研究进展

肠道病毒71型(Enterovirus71,EV71)是手足口病的主要病原体,是一种具有较强传染性和致病性的病毒,其流行范围波及全世界,近年来在亚太地区尤其是在中国的流行日趋频繁。目前EV71病原学、流行病学以及动物模型的研究均取得了一定进展,为疫苗的研发奠定了相应的基础,中国三家公司的EV71灭活疫苗现已率先获得临床批件,有望成为预防手足口病的有效手段。     

肠道病毒71型研究进展

肠道病毒71型是一种具有较强致病性的肠道病毒,主要引起患者手足口病(Hand,foot and mouth disease,HFMD)。已在世界多个地区爆发和流行,主要症状是手、足、口、臀等部位皮疹或疱疹,少数患儿可以并发无菌性脑膜炎、脑炎、急性弛缓性麻痹等严重神经系统并发症,呼吸道感染和心肌炎等,可致残、致死。2007—2008年中国多个地区均有较大规模流行,危害十分严重。近四十年的多次流行中,EV71病毒的基因不断进化,研究其基因变化特点对早期诊断、分型以及了解基因与流行、致病的关系等有着重要的意义。对EV71感染尚缺乏有效的抗病毒药物,研制有效的预防性疫苗迫在眉睫,目前有灭活疫苗、减毒疫苗、多肽或蛋白疫苗、DNA疫苗等多种尝试,但至今尚无EV71疫苗上市。本文对EV71基因、实验室诊断和疫苗方面的研究进展进行了综述。     

细胞焦亡在肠道病毒A71型感染中的作用

肠道病毒A组71型(Enterovirus A71,EV-A71)是引起手足口病(Hand,foot,and mouth disease,HFMD)最常见的病原体之一,而细胞焦亡是一种以细胞溶解及炎症反应为主要特征的细胞程序性死亡。目前细胞焦亡参与EV-A71致病的分子机制尚不清楚。本研究旨在探索EV-A71感染引起的焦亡与病毒感染之间的关系。EV-A71感染Vero细胞,6 h后检测caspase-1 mRNA和蛋白的表达水平,结果显示EV-A71感染促使caspase-1表达升高,表明EV-A71感染引起细胞焦亡;检测IL-1β和IL-18 mRNA和蛋白的表达水平,结果显示EV-A71感染促进IL-1β和IL-18的表达升高,表明EV-A71诱导的焦亡与炎症的产生有关。EV-A71感染后加入caspase-1抑制剂Ac-YVADCMK,在感染后6 h检测caspase-1和EV-A71的mRNA和蛋白的表达水平,结果显示加入Ac-YVAD-CMK可降低caspase-1和EV-A71的mRNA及蛋白水平,表明Ac-YVAD-CMK可抑制细胞焦亡和病毒的感染;检测IL-1β和IL-...     

肠道病毒71型感染患儿血中炎症因子mRNA的表达

目的探讨肠道病毒71型(EV71)感染患儿血中炎症因子mRNA的表达。方法用Real-time PCR方法检测EV71感染轻症、重症患儿和正常儿童的血中肿瘤坏死因子α(TNF-α),干扰素(IFN)-α、IFN-β,白细胞介素-6(IL-6)、IL-8、IL-12的mRNA表达。结果EV71感染患儿血中IFN-α、IL-6、IL-8、IL-12mRNA的表达增加(28±182.07 vs 5.5±0.79;30±103.30 vs 6±4.21;34±169.60 vs6.2±4.16;33.33±229.70 vs 2.6±0.92)。轻症组与重症组间比较,IFN-α、IL-12mRNA表达显著升高(40±275.86 vs 28±182.07;46.67±46.04 vs 33.33±229.7),IL-6、IL-8mRNA的表达差异无统计学意义(30±103.3 vs 32±110.5;34±169.6 vs 36.67±195.4)。结论细胞因子IFN-α、IL-6、IL-8、IL-12参与抗EV71感染过程,其中IFN-α和IL-12可能是促进EV71感染发展为重症的关键因子。     

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型疫苗的研究进展

近年来,手足口病(Hand foot mouth disease,HFMD)在中国多次爆发流行,严重威胁公众健康,尤其是5岁以下的婴幼儿。而肠道病毒71型(Enterovirus 71,EV71)是引起手足口病的主要病原体之一,由于目前还无针对该疾病有效的抗病毒药物,研制疫苗是控制EV71流行最为有效的措施。目前EV71疫苗及相关研究均取得重大突破,本文就近年来关于EV71疫苗研发、动物模型等的研究进展作一综述。     

EV71感染抗病毒药物及疫苗研究进展

手足口病在世界多个地区,尤其是亚洲爆发并流行,且其感染率和死亡率逐年增高,危害十分严重。肠道病毒71(Enterovirus 71,EV71)是手足口病(Hand,foot,andmouth disease,HFMD)的主要病原体,以感染婴幼儿为主,其感染常伴随神经系统并发症,严重可导致儿童死亡。近年来,分子生物学和抗病毒研究方面取得的进展为EV71感染的预防及治疗提供了新的途径。本文对EV71病毒学特点及抗EV71药物的筛选、疫苗开发、RNA干扰等进行了综述,以期为相关研究提供参考。     

肠道病毒71型疫苗质量控制研究进展

手足口病(Hand foot and mouth disease,HFMD)已成为西太平洋区严重的公共卫生问题之一,肠道病毒71型(Enterovirus 71,EV71)是引起HFMD的主要病原体,研发疫苗是控制HFMD流行的有效手段。目前世界范围已有5个EV71全病毒灭活疫苗进入临床试验,其中中国研制的3种EV71疫苗已分别完成III期临床试验,结果表明3种疫苗都具有良好的安全性和保护效果。在EV71疫苗研发中,抗原质控的方法和标准是研发的瓶颈,其中抗原活性测定是工序工艺优化、免疫原性评价和剂量确定的关键指标。综述了EV71疫苗抗原质控的研究进展。     

SIV vaccine protection of rhesus monkeys.

Rhesus macaques (M. mulatta), immunized with an inactivated whole SIVmac vaccine and muramyl dipeptide or Freund's incomplete adjuvant, were protected against IV challenge infection with 10 animal infectious doses of the homologous virus. The protection in these animals appeared to be complete, with no breakthrough of latent virus infection over a 10-month period. Vaccine protection in this model was correlated generally with a high level of SIVmac envelope antibody by ELISA and immunoblot, high titers of syncytial inhibiting antibody, and, more specifically, with the presence of antibodies binding to a putative V3 loop synthetic peptide of the SIVmac outer envelope. This model can now be used for further identification of the protective epitopes and protective host immune responses as well as for development of novel and better AIDS vaccines.     

Pilot scale production of highly efficacious and stable enterovirus 71 vaccine candidates

Background

Enterovirus 71 (EV71) has caused several epidemics of hand, foot and mouth diseases (HFMD) in Asia and now is being recognized as an important neurotropic virus. Effective medications and prophylactic vaccine against EV71 infection are urgently needed. Based on the success of inactivated poliovirus vaccine, a prototype chemically inactivated EV71 vaccine candidate has been developed and currently in human phase 1 clinical trial.

Principal Finding

In this report, we present the development of a serum-free cell-based EV71 vaccine. The optimization at each step of the manufacturing process was investigated, characterized and quantified. In the up-stream process development, different commercially available cell culture media either containing serum or serum-free was screened for cell growth and virus yield using the roller-bottle technology. VP-SFM serum-free medium was selected based on the Vero cell growth profile and EV71 virus production. After the up-stream processes (virus harvest, diafiltration and concentration), a combination of gel-filtration liquid chromatography and/or sucrose-gradient ultracentrifugation down-stream purification processes were investigated at a pilot scale of 40 liters each. Although the combination of chromatography and sucrose-gradient ultracentrifugation produced extremely pure EV71 infectious virus particles, the overall yield of vaccine was 7–10% as determined by a VP2-based quantitative ELISA. Using chromatography as the downstream purification, the virus yield was 30–43%. To retain the integrity of virus neutralization epitopes and the stability of the vaccine product, the best virus inactivation was found to be 0.025% formalin-treatment at 37°C for 3 to 6 days. Furthermore, the formalin-inactivated virion vaccine candidate was found to be stable for >18 months at 4°C and a microgram of viral proteins formulated with alum adjuvant could induce strong virus-neutralizing antibody responses in mice, rats, rabbits, and non-human primates.

Conclusion

These results provide valuable information supporting the current cell-based serum-free EV71 vaccine candidate going into human Phase I clinical trials.     

EV71与CA16双价灭活疫苗诱导小鼠免疫原性研究

目的评价EV71和CA16双价灭活疫苗免疫小鼠诱导的体液免疫和细胞免疫应答。方法分别应用EV71和CA16双价疫苗、EV71和CA16单价疫苗按单针、两针(0,14 d)的程序免疫小鼠,采用细胞病变法检测血清第1针免疫后21 d时中和抗体效价,应用LUMINEX液相芯片技术检测小鼠脾单个核细胞体外经抗原刺激分泌细胞因子的水平。结果双价疫苗与EV71单价疫苗单针、两针免疫相比,EV71中和抗体几何平均值相近(118.8∶84.0;159.5∶156.8,P0.05)。双价疫苗与CA16单价疫苗单针免疫诱导的CA16中和抗体均为阴性;两针免疫CA16中和抗体几何平均值一致(30.0∶26.9,P0.05)。加强免疫7 d后,小鼠脾MNC经EV71抗原刺激,双价疫苗较EV71单价疫苗诱导Th2类细胞因子IL-4、5、6、10和炎症因子TNF-α的分泌水平显著增高(P=0.020,P=0.027,P=0.038,P=0.019,P=0.026);MNC经CA16抗原刺激,双价疫苗与CA16单价疫苗相比诱导细胞因子水平差异无统计学意义(P0.05)。结论双价疫苗可诱导与单价疫苗相似的中和抗体应答水平,并可提高Th2类细胞因子应答,研究为EV71和CA16双价灭活疫苗的研发提供了实验依据。     

Prevention of disease induced by a partially heterologous AIDS virus in rhesus monkeys by using an adjuvanted multicomponent protein vaccine

Recombinant protein subunit AIDS vaccines have been based predominantly on the virus envelope protein. Such vaccines elicit neutralizing antibody responses that can provide type-specific sterilizing immunity, but in most cases do not confer protection against divergent viruses. In this report we demonstrate that a multiantigen subunit protein vaccine was able to prevent the development of disease induced in rhesus monkeys by a partially heterologous AIDS virus. The vaccine was composed of recombinant human immunodeficiency virus type 1 (HIV-1) gp120, NefTat fusion protein, and simian immunodeficiency virus (SIV) Nef formulated in the clinically tested adjuvant AS02A. Upon challenge of genetically unselected rhesus monkeys with the highly pathogenic and partially heterologous SIV/HIV strain SHIV(89.6p) the vaccine was able to reduce virus load and protect the animals from a decline in CD4-positive cells. Furthermore, vaccination prevented the development of AIDS for more than 2.5 years. The combination of the regulatory proteins Nef and Tat together with the structural protein gp120 was required for vaccine efficacy.     

Accelerated heterologous adenovirus prime-boost SIV vaccine in neonatal rhesus monkeys

A pediatric human immunodeficiency virus type 1 (HIV-1) vaccine would be desirable to protect infants against HIV-1 transmission from breast-feeding. Such a vaccine would need to induce protective immunity at mucosal surfaces in neonates as soon as possible after birth. Recombinant adenovirus (rAd) vectors have been shown to elicit potent systemic and mucosal virus-specific immune responses in adult nonhuman primates and humans, but these vectors have not previously been comprehensively studied in infants. In this study, we demonstrate that a single injection of rAd26 encoding simian immunodeficiency virus mac239 (SIVmac239) Gag on the day of birth elicited detectable Gag-specific cellular immune responses in rhesus monkeys, but these responses were transient and waned quickly. In contrast, an accelerated heterologous prime-boost regimen involving administration of rAd35 at birth and rAd26 at 4 weeks of life elicited potent and durable Gag-specific cellular and humoral immune responses in neonatal rhesus monkeys, including mucosal responses that remained detectable at 1 year of age. These results suggest the potential of an accelerated heterologous rAd prime-boost regimen as a candidate HIV-1 vaccine for newborns.