狂犬病病毒糖蛋白的性质及其应用

在狂犬病病毒各种结构蛋白中,糖蛋白是研究最广泛、最深入的一种蛋白质。它是狂犬病毒5个结构蛋白中,惟一能刺激机体产生中和抗体的抗原,与狂犬病病毒的多种生物学特性有关。根据其自身特性,狂犬病病毒糖蛋白已经应用在多个领域。本综述在系统介绍狂犬病病毒糖蛋白结构和功能的基础上,阐述其在疫苗研制、抗原抗体检测中的应用。     

云南省保山市人间狂犬病调查及病毒分子生物学特征分析

目的 了解云南省保山市发生2例狂犬病患者的流行病学特点,根据病原分子生物学特征分析可能的传染来源.方法 采用狂犬病个案调查表进行流行病学调查,采集狂犬病死者脑组织标本,用直接免疫荧光试验(DFA)检测狂犬病病毒抗原,用RT-PCR法检测狂犬病病毒核酸,测定狂犬病病毒P、M和N基因全序列并根据其同源性比较及系统进化树进行分子流行病学分析.结果2006年7月保山市隆阳区发生1例人间狂犬病,2007年4月腾冲县发生1例狂犬病.2例患者犬伤暴露程度均为Ⅲ度.2例死亡病例均采集到脑组织(编号为CYN0601H和CYN0701H),经DFA和RT-PCR两种实验室方法检测确诊为狂犬病病毒阳性.CYN0601H和CYN0701H与国内外狂犬病病毒的P、M和N基因核苷酸和推导氨基酸序列同源性分析显示,CYN0601H和CYN0701H与泰国分离株的同源性最高.系统进化分析显示,2株病毒标本亲缘关系很近,同属于狂犬病病毒基因1型,且与泰国病毒株有较近的亲缘关系.结论从病原学和病毒分子水平证实云南省保山市2例患者均为狂犬病,保山市狂犬病病毒流行株可能为境外传人,应加强云南省边境地区狂犬病防制工作.     

狂犬病病毒糖蛋白的抗原性和致病性功能研究进展

狂犬病病毒糖蛋白(GP)的抗原性和致病性研究有助于阐明病毒的免疫应答特点和致病机制,从而为狂犬病的有效防治提供科学依据.GP的抗原性不仅用于各种单克隆抗体、基因工程抗体以及新型疫苗的研究,还可辅助病毒感染的早期诊断和暴露后的早期治疗;而病毒的致病性与GP的表达水平及诱导细胞凋亡的能力有紧密联系.因此,GP的抗原性和致病性已逐渐成为人们的研究热点.该文就狂犬病病毒GP的抗原性和致病性最新研究进展予以综述.     

广西狂犬病病毒M基因序列分析

目的 探讨广西13株狂犬病病毒M基因遗传变异特征及其与狂犬病在广西流行的关系.方法 用直接免疫荧光法(DFA)检测2006～2008年广西地区收集到的3961份犬脑组织标本,将榆测结果为阳性的脑组织标本进行RT-PCR扩增,双向测序M基因核苷酸序列,进行生物信息学分析.结果 DFA法检测阳性率为8.84%(350/39...     

狂犬病病毒浙江街毒株糖蛋白基因序列分析

目的 测定狂犬病病毒浙江株(鼬獾源和犬源)糖蛋白(GP)基因组全序列,从分子水平比较狂犬病病毒浙江株与其他地区代表性街毒株和疫苗株GP之间的差异.方法 乳鼠接种分离狂犬病病毒,RT-PCR反应测定狂犬病病毒浙江株GP基因核苷酸序列,并进行序列和编码蛋白的比较分析.结果测序获得浙江5株鼬獾源狂犬病病毒和9株犬源狂犬病病毒GP基因序列,全长1575个核苷酸,编码524个氨基酸.浙江病毒株与其他地区街毒株、疫苗株核苷酸和氨基酸序列相似性在82.3%～99.9%和85.1%～99.8%之间,种系分析显示浙汀株均为基因1型,GP编码蛋白无重组,主要抗原位点未出现较大的变异.结论 对GP基因一级结构综合分析表明,在某些区域存在优势抗原表位的可能性较大,可能出现潜在的蛋白质抗原决定簇,浙江株GP基因变异较小,与国内其他地区流行的代表性街毒株相似,但高于其他疫苗株,在基因结构及种系进化关系上存在一定的距离.     

狂犬病病毒G蛋白基因重组研究

目的探讨狂犬病病毒G蛋白基因重组及其对病毒属性的影响。方法收集GenBank狂犬病病毒G蛋白基因全序列,经过MEGA4.1对齐、去除空位处理后,运用RDP 2.0软件进行筛查,然后利用SimPlot 3.5.1软件进行相似性分析和BOOTSCAN分析,对基因重组加以验证,并构建最大似然进化树,观察重组片断拓扑结构的改变。结果利用RDP 2.0软件共检测到3个重组序列,分别是DQ849069、AF334789与AY009100。相似性分析和BOOTSCAN分析确认重组序列DQ849069重组特征明显,重组片段为746～1 566nt,重组片断最大似然进化树的拓扑结构也发生了相应改变。而AF334789与AY009100未发现有意义重组信号;地缘分析表明DQ849069是基因重组的产物。结论狂犬病病毒G蛋白在进化过程中存在重组,重组事件对未来病毒毒力的影响有待于深入研究。     

无菌性脑膜炎暴发中Echo30病毒的基因特征及分子进化分析

目的了解引起无菌性脑膜炎暴发的Echo30病毒的基因特征，分析其遗传变异规律及进化来源。方法对2003年济南章丘市无菌性脑膜炎暴发中分离到的Echo30病毒进行了VPI区全基因序列测定，与国内外报道的Echo30病毒VPU区序列进行同源性比较，并通过构建进化树分析其遗传进化规律。结果济南章丘市Echo30分离株VPI区核苷酸同源性在98．9％～99．5％之间，与同年山东省泰安市Echo30分离株同源性最高（98．5％～990％），与浙江、江苏两省的Echo30分离株同源性在98．2％～98．9％，而与1997年法国分离株（89．1％～897％）和2001年台湾省分离株（87．4％～87．6％）的同源性相差较大，与原型株Bastianni株同源性最低，在82．4％～82．8％。进化树分析显示，中国大陆近几年无菌性脑膜炎Echo30分离株独处一支，呈单源性发生关系。结论2003年，Echo30病毒在山东省部分地区发生了一定程度的传播，并导致了无菌性脑膜炎的局部流行，进化树分析表明，中国大陆Echo30分离株与国外早期的分离株相比，其抗原性不完全相同，已形成新的基因亚型。     

广西狂犬病病毒与狂犬病疫苗株N基因序列分析

目的了解广西狂犬病病毒（RABV）街毒株与疫苗株N基因序列的差异,为疫苗使用提供理论依据。方法采用直接免疫荧光法（DFA）和巢式RT—PCR法检测,测定病毒N基因序列全长,同时根据N基因序列同源性及系统进化树比较,分析广西近年流行的RABV与国内外10株疫苗代表株N基因序列之间的差异。结果DFA法阳性率为8．84％（350／3961）,RT—PCR法检测阳性率1．29％（51／3961）,获得N基因全序15份;15份N基因核苷酸与氨基酸序列同源性为89．40％。100％和98．40％~99．80％;广西15份（RABV）与国内外10株疫苗代表株N基因核苷酸和氨基酸序列同源性分别为85．70％～99．70％和94．90％～99．80％,与中国CTN疫苗株N基因的核苷酸和氨基酸同源性最高,分别为89．60％,99．70％和98．40％。99．80％。N基因系统发生树分为两大分支,15份（RABV）与中国人用CTN株构成第一分支,其余的疫苗毒株构成第二分支。结论广西犬间流行的RABV与中国人用CTN疫苗株N基因序列同源性最高、亲缘关系最近,在广西地区使用CTN疫苗株效果可能较好。     

广西玉林市2005—2012年狂犬病病原学监测及病毒N基因特征分析

目的分析2005—2012年广西玉林市狂犬病病原学监测结果及病毒N基因遗传变异特征,为狂犬病防控提供科学依据。方法 2005—2012年在广西玉林市采集犬脑组织及临床诊断人狂犬病病例的唾液进行病原学检测,检测阳性标本进行N基因核苷酸序列测定、同源性比较和种系发生分析。结果共采集、检测外观健康犬脑组织728份、临床诊断人狂犬病病例唾液33份,RT-PCR检测阳性率分别为0.96%(7/728)和51.52%(17/33)。获得5条犬源、6条人源狂犬病病毒株N基因全序列。该11条序列之间的核苷酸同源性为94.7%~100.0%,与广西以往分离株GX01的核苷酸序列的同源性为94.5%~98.4%,与疫苗株CTN株的同源性为94.6%~99.7%。进化树分析显示,犬源株和人源株病毒N基因亲缘进化关系很近,处于同一分支,都属于基因Ⅰ型狂犬病病毒。结论从病原学和病毒分子水平证实玉林市外观健康犬携带狂犬病毒及17例临床诊断病例为确诊病例,其病原为狂犬病病毒基因I型,阳性带毒犬的流动是造成本病传播和扩散的主要因素,也是造成该地区疫情高发的重要原因之一。     

狂犬病病毒分子流行病学研究进展

狂犬病病毒分子流行病学研究是防控狂犬病暴发的前提.已有的研究成果显示,对狂犬病病毒分子流行病学研究以全基因组测序为好,提高犬狂犬病疫苗免疫覆盖率和建立健全狂犬病疫情预警网络平台可能是扭转我国目前狂犬病高发的关键所在.此文综述了基因序列分析和氨基酸序列分析的狂犬病病毒分子流行病学研究进展.     

狂犬病病毒时空进化研究进展

目前人类正处于传染性疾病全球性危机的境地，任何一个国家都不可能幸免新老传染病的威胁。之所以不断有新病原体产生是因为传染病病原体一直在变异，这种变异来源于对外界环境阻力和免疫压力的反应，通过变异企图突破阻力进一步扩散或逃过宿主的免疫压力继续生存。因此传染病的发生和不断流行都与病原体的变异有关，这种变异就是进化，     

广西狂犬病病毒分子流行病学研究

目的分析广西狂犬病毒的分布和来源,从病原学角度分析广西狂犬病疫情高发的原因。方法2005年9月~2006年4月在广西玉林、贵港、柳州、来宾、南宁和河池等6市共收集健康犬脑标本1 352份,用直接免疫荧光法(DFA)和RT-PCR法检测狂犬病毒,其中22份标本完成狂犬病毒N基因编码区下游720bp核苷酸序列的测定。结果用DFA法检测出阳性标本160份,阳性率为11.83%,RT-PCR检测出阳性标本26份,阳性率1.9%,对其中22份标本完成N基因编码区下游720bp核苷酸序列的测定,核苷酸序列同源性为87.8%~100%,推导氨基酸序列的同源性为97.5%~99.6%,表明广西病毒标本N基因核苷酸序列的变异主要是同义突变。种系发生分析显示,广西病毒标本分为A、B、C群,各群分布范围不同,具有明显地域性特征;中国存在的3群狂犬病毒(CHINA-1、CHINA-2和CHINA-3群)目前在广西均有分布。广西流行的3群病毒来源各不相同:A群可能来源于与广西相邻的湖南、贵州;B群可能由广西北部省区传入;C群是在广西境内循环的毒株。结论广西境内普遍存在狂犬病毒感染犬只,并有外省狂犬病毒的传入,可能是近年广西狂犬病疫情上升的重要原因。     

Complex genetic structure of the rabies virus in Bangkok and its surrounding provinces, Thailand: implications for canine rabies control

Dog vaccination and population management have been suggested as priorities in attempts at disease control in canine rabies-endemic countries. Budget limitations and the complexity of social, cultural and religious variables have complicated progress in the developing world. In Bangkok, Thailand, an intensive canine vaccination and sterilization programme has been in place since November 2002. Our objective was to determine if the rabies virus could be mapped according to its genetic variations and geographical location on the small localized scale of Bangkok and its surrounding provinces. Phylogenetic characterization of 69 samples from Bangkok and five neighbouring and two remote provinces, by limited sequence analysis of the rabies virus nucleoprotein gene, distinguished six different clades. Rabies viruses of four clades were intermixed in Bangkok and in the surrounding highly populated regions whereas the other two clades were confined to rural and less populated provinces. Such a complex pattern of gene flow, particularly in Bangkok, may affect the outcome of canine control programmes.     

Generation of a live rabies vaccine strain attenuated by multiple mutations and evaluation of its safety and efficacy

An amino acid substitution at position 333 in rabies virus G protein is known to determine the pathogenicity: strains with Arg or Lys at that position kill adult mice after intracerebral inoculation, whereas strains with other amino acids cause non-lethal infection. Based on those findings, attenuated rabies virus strains have been established and used for oral vaccines mainly for wild animals. However, considering the possibility of back-mutation to the virulent phenotype, a strain that is attenuated by multiple mutations not only in the G protein but also in other viral proteins would be more appropriate as a safe live vaccine. We previously demonstrated that the fixed rabies virus Ni-CE strain, which causes only transient body weight loss in adult mice after intracerebral inoculation, is mainly attenuated by mutations in the N, P and M proteins, while this strain has virulent-type Arg at position 333 in the G protein. In this study, to obtain a live vaccine strain that is attenuated by multiple mutations, we generated Ni-CE mutant, Ni-CE(G333Glu) strain, which has an Arg-to-Glu mutation at position 333 in the G protein, and examined its pathogenicity and immunogenicity. We found that, in contrast to Ni-CE strain, Ni-CE(G333Glu) strain did not cause transient body weight loss in adult mice after intracerebral inoculation. The attenuated phenotype of Ni-CE(G333Glu) strain did not change even after 10 serial intracerebral passages in suckling mice. We also demonstrated that inoculation of Ni-CE(G333Glu) strain induced virus-neutralizing antibody in immunized mice and protected the mice from lethal challenge. These results indicate that Ni-CE(G333Glu) strain is a promising candidate for development of a live rabies vaccine with a high safety level.     

Enhancing comparative rabies DNA vaccine effectiveness through glycoprotein gene modifications

Enhancing DNA vaccine effectiveness remains a challenge, especially if the desired goal is immunization efficacy after a single dose. The glycoprotein gene from the rabies virus Evelyn–Rokitnicki–Abelseth (ERA) strain was modified by mutation at amino acid residue 333 from arginine to glutamine. The modified and original unmodified glycoprotein genes were cloned separately and developed as DNA vaccines for immunization in mice. The intramuscular (IM) route using a single dose (100 μg) of a modified DNA vaccine showed virus neutralizing antibody induction by d30, and 80% of the mice survived a challenge in which 100% of unvaccinated controls succumbed. Similar results were obtained using a single dose (10 μg) by the intradermal (ID) route with one-tenth amount of the DNA administered. Administration of single dose of DNA vaccine with unmodified G did not result in the production of detectable levels of virus neutralizing antibody by d30. The results of the IM and the ID routes of administration were statistically significant (P < 0.01). Based on these preliminary results, a modified glycoprotein gene from the ERA rabies virus strain may be an ideal candidate for DNA vaccine efficacy enhancement.     

河南省两株狂犬病毒核蛋白和糖蛋白基因的序列分析

目的分析河南省2株狂犬病毒核蛋白及糖蛋白的基因序列,了解狂犬病毒街毒株与人用及兽用狂犬病疫苗株间的差异。方法以免疫荧光法检测2004年采自河南省的100只犬脑标本,取阳性犬脑组织悬液接种鼠脑分离病毒。以RT-PCR法扩增病毒核蛋白及糖蛋白全基因,克隆测序后进行遗传学分析。结果分离到2株狂犬病毒,分别命名为Henan Hb1与Henan Sq1,序列分析表明2株病毒均为基因1型狂犬病毒,2株病毒的N基因与G基因核苷酸的同源性分别为99.3%和98.9%,氨基酸的同源性分别为98.7%和98.4%。2株病毒与CTN疫苗株同源性较高,N基因与G基因的核苷酸同源性分别为89.1%和85.6%～85.7%,氨基酸同源性分别为97.6%～98.0%和92.3%。与已知的基因1型狂犬病毒相比,2株病毒与印度尼西亚从犬中分离到的2株病毒同源性最高,N基因与G基因核苷酸同源性分别为92.1%～93.2%和91.9%～92.1%,氨基酸同源性分别为97.5%～98.6%和96.0%～96.2%。Henan Sq1株病毒在糖蛋白关键的毒力位点333位由W替换了R。系统发育分析表明Henan Hb1与Henan Sq1与印度尼西亚株、疫苗株CTN、中国分离株,以及泰国与马来西亚分离株进化关系最近,而与疫苗株3aG、PV、ERA及攻击毒CVS株等进化关系较远。结论2株狂犬病毒是基因1型狂犬病毒,但无论是N基因还是G基因的核苷酸序列,以及推导出来的氨基酸序列与已知的1型狂犬病毒株及疫苗株均有一定的差异。     

Phylogenetic analysis of nucleoprotein gene of dog rabies virus isolates from Southern India

India like several other South East Asian and African countries continues to face the public health and economic problems associated with the disease. Our objective was to perform a limited sequence analysis of a portion of nucleoprotein gene of 22 rabies virus isolates obtained from domestic animals in Southern India during 2004–2005. These isolates were compared with rabies virus isolates originating from Asia, Europe, Africa and North America. The phylogenetic analysis showed that RV isolates in Southern India belong to genotype 1. They were similar to one another forming a single major genetic cluster not ordered by geography or species of origin. However, they were dissimilar to RV isolates in Northern India and in other parts of the world. The data indicated that dog rabies virus variants are the major circulating viruses and control of dog rabies would result in overall reduction in the burden and incidence of rabies in India.     

Live attenuated rabies virus co-infected with street rabies virus protects animals against rabies

While current rabies post-exposure prophylaxis (PEP) is highly effective, it is costly and the vaccination regimen is complicated, requiring both inactivated vaccines and immunoglobulins. A one-dose rabies vaccine for human PEP remains a long-term goal. Here, we describe development of a highly attenuated rabies virus ERAg3m, with a mutation in the glycoprotein (G) gene and a switch of the G gene with the matrix protein gene in the viral genome. After a one-dose intramuscular vaccination, the ERAg3m virus protected 100% of mice and hamsters from lethal challenge. In co-infections, using a lethal dose of street rabies virus mixed with ERAg3m, 100% of hamsters and 90% of mice survived and were protected against subsequent infection. A mock co-infection, using inactivated commercial human rabies vaccine and a lethal dose of street rabies virus, protected 100% and 40% of hamsters and mice, respectively. In co-infections, when vaccine was administrated in the left leg and challenge virus in the right leg, the ERAg3m virus protected 40% of mice, while the inactivated vaccine showed no protection. Therefore, live attenuated rabies virus when given pre-exposure or co-infected with street rabies virus, is capable of preventing rabies in two different animal models. Overall, this highly attenuated live rabies virus offered better protection than the inactivated vaccine.     

狂犬病病毒致病机制研究概况

狂犬病病毒（RV）是一种高度嗜神经性病毒，由RV引发的狂犬病通常是一种急性致死性神经系统损伤性疾病。RV通过周围神经末梢和中枢神经系统（CNS）的神经元进行病毒的复制和传播。绝大多数狂犬病例CNS病理学表现为急性脑脊髓炎，常常没有显著的显微镜下改变，脑部可以轻度肿胀，脑膜和脑实质血管轻度充血并伴有少量炎症细胞浸润，这也是其他急性病毒性脑炎常见的共同表现。