流感病毒H3N2血凝素基因和神经氨酸酶基因在大肠杆菌中的表达

克隆、表达和鉴定流感病毒H3N2 HA,NA基因序列,为制备抗体和基因工程疫苗打下基础。在成功克隆流感病毒H3N2全长HA、NA基因并测序的基础上,将部分基因序列克隆到表达载体pET32a(+)上,全基因序列克隆到表达载体pGEX4T-1上,构建了重组表达质粒pET32a(+)/HA(截短),pET32a(+)/NA(截短),pGEX4T-1/HA,转化大肠杆菌BL21/Rosetta,IPTG诱导表达,利用Ni2+亲和层析柱和GSTrap 4B亲和层析柱对重组蛋白进行纯化,并用Western blotting和ELISA方法检测其抗原性。结果显示,重组蛋白在大肠杆菌中可以高效表达,SDS-PAGE显示其相对分子质量与预计大小一致。ELISA和Western blotting试验证实,重组蛋白具有良好的抗原性。成功克隆和表达了流感病毒H3N2 HA、NA基因序列,可为流感病毒H3N2诊断试剂和疫苗的开发等进一步的研究提供参考。     

猪流感病毒H1N1血凝素基因和神经氨酸酶基因在大肠杆菌中的表达

克隆、表达和鉴定猪流感病毒H1N1 HA,NA基因序列,为制备抗体和基因工程疫苗打下基础。在成功克隆猪流感病毒H1N1全长HA、NA基因并测序的基础上,将部分基因序列克隆到表达载体pET32a(+)上,全基因序列克隆到表达载体pGEX4T-1上,构建了重组表达质粒pET32a(+)/HA(截短),pET32a(+)/NA(截短),pGEX4T-1/NA,转化大肠杆菌BL21/Rosetta,IPTG诱导表达,利用Ni2+亲和层析柱和GSTrap 4B亲和层析柱对重组蛋白进行纯化,并用Western Blotting和ELISA方法检测其抗原性。结果显示,重组蛋白在大肠杆菌中可以高效表达,SDS-PAGE显示其相对分子质量与预计大小一致。ELISA和Western blotting试验证实,重组蛋白具有良好的抗原性。本研究成功克隆和表达了猪流感病毒H1N1 HA、NA基因序列,为猪流感病毒H1N1诊断试剂和疫苗的开发等进一步的研究奠定了基础。     

禽流感病毒H9N2血凝素基因和神经氨酸酶基因在真核酵母菌中的表达

目的:克隆、表达和鉴定禽流感病毒H9N2血凝素基因(hemagglutinin,HA)和神经氨酸酶基因(neuramidinase,NA)序列,为制备抗体和基因工程疫苗打下基础。方法:在成功克隆禽流感病毒H9N2全长HA、NA基因并测序的基础上,将部分基因序列克隆到表达载体pMETA上,构建了重组表达质粒pMETA/HA(52～1545bp),pMETA/NA(121～1254bp),电转化真核酵母菌pMAD16,甲醇诱导表达,利用Ni2+亲和层析柱对重组蛋白进行纯化,并用Western blotting和ELISA方法检测其抗原性。结果:重组蛋白在酵母菌中可以高效表达,SDS-PAGE显示蛋白表达后形成了二聚体,蛋白纯度占总蛋白的95%以上,ELISA和Western blotting实验证实,重组蛋白具有良好的抗原性。结论:成功克隆和表达了禽流感病毒H9N2HA、NA基因序列,为禽流感病毒H9N2诊断试剂和疫苗的开发等进一步的研究奠定了基础。     

禽流感病毒H5N1血凝素基因和神经氨酸酶基因在大肠杆菌中的表达

目的：克隆、表达和鉴定禽流感病毒H5N1血凝素基因（hemagglutinin,HA）和神经氨酸酶基因（neuramidinase,NA）序列,为制备抗体和基因工程疫苗打下基础。方法：在成功克隆禽流感病毒H5N1全长HA、NA基因并测序的基础上,将部分基因序列克隆到表达载体pET32a（＋）上,全基因序列克隆到表达载体pGEX4T-1上,构建了重组表达质粒pET32a（＋）/HA(49~1587bp)、pET32a（＋）/NA(121~1141bp)、pGEX4T-1/HA、pGEX4T-1/NA,转化大肠杆菌BL21/rosetta,IPTG诱导表达,利用Ni2＋亲和层析柱和GSTra P4B亲和层析柱对重组蛋白进行纯化,并用Western blotting和ELISA方法检测其抗原性。结果：重组蛋白在大肠杆菌中可以高效达,SDS PAGE显示其相对分子质量与预计大小一致,蛋白纯度占总蛋白的90％以上。ELISA和Western blotting实验证实,重组蛋白具有良好的抗原性。结论:成功克隆和表达了禽流感病毒H5N1 HA、NA基因序列,为禽流感病毒H5N1诊断试剂和疫苗的开发等进一步的研究奠定了基础。     

禽流感病毒H9N2血凝素基因和神经氨酸酶因在大肠杆菌中的表达

克隆、表达和鉴定禽流感病毒H9N2 HA,NA基因序列,为制备抗体和基因工程疫苗打下基础。在成功克隆禽流感病毒H9N2全长HA、NA基因并测序的基础上,将部分基因序列克隆到表达载体pET32a(+)上,全基因序列克隆到表达载体pGEX4T-1上,构建了重组表达质粒pET32a(+)/HA(截短)、pET32a(+)/NA(截短)、pGEX4T-1/HA、pGEX4T-1/NA,转化大肠杆菌BL21/rosetta,IPTG诱导表达,利用Ni2+亲和层析柱和GSTrap4B亲和层析柱对重组蛋白进行纯化,并用Western Blotting和ELISA方法检测其抗原性。结果重组蛋白在大肠杆菌中可以高效表达,SDS-PAGE显示其相对分子质量与预计大小一致。ELISA和Western Blotting实验证实,重组蛋白具有良好的抗原性。本研究成功克隆和表达了禽流感病毒H9N2 HA、NA基因序列。为禽流感病毒H9N2诊断试剂和疫苗的开发等进一步的研究奠定了基础。     

H1N1型流感病毒神经氨酸酶的原核表达、纯化及免疫原性分析

目的：研究H1N1型流感病毒神经氨酸酶（NA）在原核系统中的表达、纯化方法及其免疫原性。方法：构建了大肠杆菌表达载体pET22b-NA,并转化了大肠杆菌BL21（DE3）;通过SP-Sepharose Fast Flow柱对重组NA进行分离纯化,并用Sephadex G-25柱对SP柱后获得的NA进行柱上复性;用不同剂量的重组NA免疫BALB/c小鼠,并检测其诱导产生的抗体滴度。结果：大肠杆菌表达的NA以包涵体形式存在,通过分离及柱上复性,纯化得到重组NA;NA抗原的免疫原性是剂量依赖的,随着剂量的增加,其免疫原性相应增强,3次免疫后,3μg NA诱导小鼠产生的抗体滴度最高,为1∶7000。结论：大肠杆菌表达的NA具有一定的诱导小鼠产生针对天然NA的抗体的能力,为流感病毒基因工程疫苗研究提供了初步线索。     

流感病毒血凝素基因、神经氨酸酶基因在小鼠中的免疫效果观察

流感病毒血凝素基因,神经氨酸酶基因免疫BALB／c小鼠,获得特异阳性抗体反应,抗体滴度与基因免疫量呈正相关性,各实验组免疫小鼠抗同型流感病毒攻击存活率为100％,血凝素基因免疫小鼠抗异型流感病毒攻击存活率为100％,神经氨酸酶基因免疫小鼠抗异型流感病毒攻击存活率为75％,血凝素基因与神经氨酸酶基因联合免疫小鼠抗异型流感病毒攻击存活率为100％。     

云南省2009～2014年甲型H1N1流感病毒HA及NA基因特征分析

了解云南省2009~2014年甲型H1N1流感病毒的流行趋势,研究HA和NA基因进化特征。对云南省近6年来上报的流感监测病例数据进行病原谱总结,挑选出23株甲型H1N1流感毒株进行HA及NA基因分析。利用MEGA 5.0软件对测序结果构建进化树分析基因同源性。2009~2014年云南省共监测到4次甲型H1N1流感流行高峰,核酸检测结果中甲型H1N1流感占检出总量的28.8%。测序结果显示,HA与NA基因均分为3个类群,检测到一株具有H275Y突变位点的毒株。甲型H1N1流感是导致本省流感流行的重要亚型之一,2009~2014年间分离的毒株主要有Goup1、Gourp7和Gourp6三个支系,绝大部分甲型H1N1流感毒株仍对神经氨酸酶抑制剂敏感。     

广州2006年乙型流感病毒血凝素和神经氨酸酶基因特性分析

为了解2006年广州地区流行的乙型流感病毒株血凝素(HA)和神经氨酸酶(NA)的基因特性,选择病原学监测病毒株和暴发性疫情病毒株,提取病毒RNA并逆转录为cDNA,通过PCR方法扩增乙型流感病毒HA和NA全长基因,将扩增的DNA片段接入T-A克隆载体进行测序,并使用DNAStar软件对测序结果进行分析。结果显示:不同来源的流感病毒株HA的同源性为99%以上,都属于Victoria系;不同来源的病毒株NA同源性为98%以上。HA和NA的种系发生树分析表明:病原学监测毒株同源性更接近,而暴发性疫情毒株的同源性则相对较为分散。所有毒株与WHO推荐的2005~2006年度疫苗株B/Shanghai/361/2002的同源性只有88.9%~89.7%,说明该年度的流感疫苗对乙型流感不能提供最佳的保护。     

一株2011年出现的季节性甲型H1N1流行性感冒病毒血凝素基因特性的研究

本文通过比较2011年分离培养的1株季节性甲型H1N1流行性感冒(简称流感)病毒(A/Shanghai/1167/2011(H1N1))与历年季节性甲型H1N1流感病毒的血凝素(HA)基因,追溯该病毒的基因变异与来源,探讨该毒株的出现对流感防控工作的意义.采用反转录-聚合酶链反应(RT-PCR)方法扩增病毒的HA和神经氨酸酶(NA)片段,并进行测序;应用分子生物学软件对获得的序列进行分析,绘制基因进化树;同时,通过血凝抑制试验检测2011年下半年健康人群中该流感病毒的抗体水平.结果显示,A/Shanghai/1167/2011(H1N1)的HA基因序列与世界卫生组织(WHO)2007～2008年季节性甲型H1N1流感病毒疫苗株A/Brisbane/59/2007(H1N1)最接近,同源性达99.2%,与新型甲型H1N1流感病毒A/California/07/2009疫苗株同源性仅为72.4%.其HA基因裂解位点为PSIQSR↓GLF,尚未出现高致病性的分子特征.HA片段共编码557个氨基酸,有9个潜在的糖基化位点,序列与2009年前WHO疫苗株A/NewCaledonia/20/1999(H1N1)、A/SolomonIslands/3/2006(H1N1)和/Brisbane/59/2007(H1N1)相比,分别有15、12和4处不同,这些差异分布在Sa、Sb、Ca1、Ca2、Cb 5个抗原决定簇的氨基酸差异分别有5、5和2处.该毒株在健康人群血清的抗体阳性率为34.33%,几何平均效价(GMT)为10.38.A/Shanghai/1167/2011(H1N1)是2011年出现在上海地区的一个季节性甲型H1N1流感病毒毒株,其抗原变异与既往季节性甲型H1N1流感病毒相比不大,但在以A(H1N1)pdm09为主要流行株的年份检测到散在发生的既往季节性甲型H1N1流感病毒毒株应当引起重视,其在人群中的抗体水平较低,易引起流行,需要提高对类流感人群中此种毒株的持续监测.     

A/swine/H1N1流感病毒中国分离株血凝素进化分析

2009年3月以来,甲型H1N1病毒已在全球包括中国造成了巨大的危害,所以利用生物信息技术对其进行研究显得十分必要。从NCBI数据库下载中国大陆境内A/swine/H1N1病毒HA基因核酸序列及其编码蛋白序列,利用MEGA4.0软件对核苷酸编码序列构建系统进化树,利用BioEdit软件对蛋白序列进行比对,分析重要抗原位点变异情况,结果显示2010年在广东流行的病毒,从其他地方传播到广东的,而非早期广东流行的的病毒变异而来。2008年福建,山东,北京等地区的病毒传播比较迅速.这些分析结果阐明了中国大陆境内A/swine/H1N1病毒血凝素(HA)基因的进化关系和变异趋向,对于研究A/swine/H1N1病毒具有重要的参考价值。     

H1亚型猪流感病毒抗体间接ELISA检测方法的建立及其应用

为建立H1亚型猪流感病毒抗体检测方法,扩增了H1N1亚型猪流感病毒流行株的血凝素基因HA1部分,构建原核表达载体pET30a-HA1,并转化大肠杆菌BL21表达重组蛋白。对重组蛋白包涵体进行变性、复性和Ni-NTA亲和层析纯化。以纯化后的蛋白作包被抗原,建立间接ELISA检测方法。利用该检测方法检测了2008?2009年采集的猪血清785份,阳性率为15.54％,不同省份的阳性率存在差异 (8％~47％)。以IDEXX相关试剂盒检测结果作为参照,该方法的诊断特异性达到91％,诊断敏感性达到95％。     

A/H6N1亚型禽流感病毒致病性评估及与2009 A/H1N1亚型流感病毒在哺乳动物体内的遗传兼容性

目的探讨人、禽流感病毒在哺乳动物体内的遗传兼容性,为下一步研究H6亚型禽流感病毒重配和致病性变异的分子机制奠定基础。方法野鸭源A/H6N1亚型禽流感病毒A/Mallard/SanJiang/275/2007以101EID50～106EID50的攻毒剂量经鼻内途径感染小鼠,通过临床症状观察、病毒滴定和病理切片观察进行病毒学和组织学两方面检测对小鼠的致病性;同时,将此病毒与2009年A/H1N1流感病毒A/Changchun/01/2009(H1N1)混合感染豚鼠,分析两株病毒在哺乳动物体内的遗传兼容性。每天采集豚鼠鼻洗液并用噬斑纯化技术获得重配病毒,对获得的重配病毒进行全基因组序列的测定。结果 H6N1亚型禽流感病毒能直接感染小鼠,但对小鼠不致死。106EID50的攻毒剂量可有效感染小鼠,攻毒后第5天,小鼠表现出被毛较粗乱、活动减少、体重下降、呼吸急促的临床症状,但至攻毒后第10天开始康复,而对照组(MOCK)小鼠在14 d的观察期内无明显临床症状。病毒滴定结果表明,该病毒主要在小鼠肺脏和鼻甲骨中复制,病毒滴度可达104.5EID50/mL。病理学观察发现感染小鼠肺泡壁增厚,有大量炎性细胞浸润,纤维蛋白渗出并伴有轻微出血;在A/H6N1和A/H1N1混合感染豚鼠的重配实验中,经过三轮噬斑纯化从豚鼠鼻洗液中分离到6株重配病毒,说明A/H6N1亚型禽流感病毒与A/H1N1亚型流感病毒具有很好的遗传兼容性,能在豚鼠体内能发生重配。结论野鸭源A/H6N1亚型流感病毒无需适应就能够感染哺乳动物;该病毒与A/H1N1流感病毒具有很好的遗传兼容性,在哺乳动物体内能够发生基因重配,产生新的重配病毒,其公共卫生意义应引起高度关注。     

Pandemic swine influenza virus (H1N1): A threatening evolution

“Survival of the fittest” is an old axiom laid down by the great evolutionist Charles Darwin and microorganisms seem to have exploited this statement to a great extent. The ability of viruses to adapt themselves to the changing environment has made it possible to inhabit itself in this vast world for the past millions of years. Experts are well versed with the fact that influenza viruses have the capability to trade genetic components from one to the other within animal and human population. In mid April 2009, the Centers for Disease Control and Prevention and the World Health Organization had recognized a dramatic increase in number of influenza cases. These current 2009 infections were found to be caused by a new strain of influenza type A H1N1 virus which is a re-assortment of several strains of influenza viruses commonly infecting human, avian, and swine population. This evolution is quite dependent on swine population which acts as a main reservoir for the reassortment event in virus. With the current rate of progress and the efforts of heath authorities worldwide, we have still not lost the race against fighting this virus. This article gives an insight to the probable source of origin and the evolutionary progress it has gone through that makes it a potential threat in the future, the current scenario and the possible measures that may be explored to further strengthen the war against pandemic.     

Immunogenicity and safety of H1N1 influenza hemagglutinin protein expressed in a baculovirus system

Although most influenza vaccines are produced in eggs, new types of vaccines must be developed. In this study, the immunogenicity and safety of a baculovirus‐expressed hemagglutinin (HA) of H1N1 influenza virus (Korea/01/2009; designated “HA‐Bac‐K”) was compared with those of a commercially available baculovirus‐expressed HA (designated “HA‐Bac‐C”) and an Escherichia coli‐expressed HA (designated “HA‐E. Coli‐K”). HA‐Bac‐K succeeded in inducing hemagglutination inhibition and neutralization antibodies in mouse and ferret models. The different immunogenicities observed may be attributable to the different expression systems and purification protocols used. Our work suggests that HA expressed in a baculovirus system is an effective and safe candidate influenza vaccine.     

Isolation and genetic characterization of avian-like H1N1 and novel ressortant H1N2 influenza viruses from pigs in China

As pigs are susceptible to both human and avian influenza viruses, they have been proposed to be intermediate hosts or mixing vessels for the generation of pandemic influenza viruses through reassortment or adaptation to the mammalian host. In this study, we reported avian-like H1N1 and novel ressortant H1N2 influenza viruses from pigs in China. Homology and phylogenetic analyses showed that the H1N1 virus (A/swine/Zhejiang/1/07) was closely to avian-like H1N1 viruses and seemed to be derived from the European swine H1N1 viruses, which was for the first time reported in China; and the two H1N2 viruses (A/swine/Shanghai/1/07 and A/swine/Guangxi/13/06) were novel ressortant H1N2 influenza viruses containing genes from the classical swine (HA, NP, M and NS), human (NA and PB1) and avian (PB2 and PA) lineages, which indicted that the reassortment among human, avian, and swine influenza viruses had taken place in pigs in China and resulted in the generation of new viruses. The isolation of avian-like H1N1 influenza virus originated from the European swine H1N1 viruses, especially the emergence of two novel ressortant H1N2 influenza viruses provides further evidence that pigs serve as intermediate hosts or “mixing vessels”, and swine influenza virus surveillance in China should be given a high priority.     

Highly pathogenic H5N1 influenza virus causes coagulopathy in chickens

Severe hemorrhage at multiple organs is frequently observed in chickens infected with highly pathogenic avian influenza (HPAI) A viruses. In this study we examined whether HPAI virus infection leads to coagulation disorder in chickens. Pathological examinations showed that the fibrin thrombi were formed in arterioles at the lung, associated with the viral antigens in endothelial cells of chickens infected intravenously with HPAI virus. Hematological analyses of peripheral blood collected from the chickens revealed that coagulopathy was initiated at early stage of infection when viral antigens were detected only in the endothelial cells and monocytes/macrophages. Furthermore, gene expression of the tissue factor, the main initiator of blood coagulation, was upregulated in the spleen, lung, and brain of HPAI virus-infected chickens. These results suggest that dysfunction of endothelial cells and monocytes/macrophages upon HPAI virus infection may induce hemostasis abnormalities represented by the excessive blood coagulation and consumptive coagulopathy in chickens.