单向放射免疫扩散法测定流感灭活疫苗血凝素含量的研究

为改进流感灭活疫苗血凝素含量的测定方法 ,将待测样品经去污剂处理后 ,用WHO标准品作对照进行免疫扩散测定 10个流感灭活疫苗样品血凝素含量。在血凝效价相同的情况下 ,疫苗中三价 (A1,A3,B)血凝素含量存在不同程度的差异。可见 ,单向放射免疫扩散法较血球凝集法更适用于流感灭活疫苗血凝素含量的测定。     

四价流感病毒裂解疫苗B型血凝素含量的检测方法

目的建立能准确测定四价流感病毒裂解疫苗中B型血凝素含量(单向免疫扩散法,SRD)的检测方法。方法采用双价抗原参考品SRD法对四价流感病毒裂解疫苗中两种B型血凝素含量进行测定。将B1与B2抗原参考品按质量浓度1∶1混合制备为双价抗原参考品,双价抗原和待检样品与10%裂解剂按9∶1比例裂解30 min,分别加入到含有抗血清参考品的1.5%琼脂糖凝胶板上,每孔10μL,置20~25℃放置18~24 h,经干燥、染色、脱色,测量结果。验证双价抗原SRD法的重复性和准确性。结果双价抗原SRD法测定的血凝素含量平均值比单价抗原SRD法更接近理论配制值,故双价抗原SRD法比单价抗原SRD法能更能准确检测QIV中两种B型血凝素含量,经验证双价抗原SRD法的重复性及准确性良好。结论双价抗原SRD法提高了四价流感病毒裂解疫苗B型血凝素含量检测的准确性,为精确测定四价流感病毒裂解疫苗中B型血凝素含量提供了有效的方法和数据支持。     

流感疫苗单向免疫扩散试验中抗血清制备新方法的研究

流感疫苗血凝素含量检测方法为单向免疫扩散试验,其抗血清通常由WHO参比实验室提供,通过纯化病毒、蛋白酶切获得血凝素主要抗原片段,然后再免疫动物获得抗血清。该方法制备时间较长,是制约流感疫苗研发及检测的主要因素。以RT-PCR方法获取甲型H1N1流感病毒血凝素中主要抗原片段基因,构建重组质粒并在大肠杆菌中表达,表达产物经纯化、复性后,以蛋白电泳及免疫印迹方法进行了鉴定。以纯化蛋白免疫家兔,制备了相应的抗体,初步证明可用于常规的单向免疫扩散试验。以该法可以快速获得抗血清,尤其是在大流行流感疫苗的研发中,加快疫苗研发进程。     

甲型H1N1流感疫苗中神经氨酸酶含量双抗体夹心ELISA检测方法的建立与应用

目的建立甲型H1N1流感疫苗中神经氨酸酶(Neuraminidase,NA)含量双抗体夹心ELISA检测方法,并对其进行验证及初步应用。方法以HCA3通用抗体作为包被抗体,N1抗血清作为显示抗体建立双抗体夹心ELISA,确定线性范围,验证该方法的准确度及精密度,并用该方法对3个厂家共9批次甲型H1N1流感疫苗中的NA含量进行测定。结果 NA质量浓度在0~50 ng/m L时线性良好(r20.99);回收率为97.54%~104.02%;实验内CV10%,实验间CV15%。不同厂家的甲型H1N1流感疫苗中NA含量差异很大,NA与HA(血凝素)的百分比最高达到29.85%,而最低的只有7.00%;而同一厂家各批次疫苗间的NA与HA的比例较为稳定。结论成功建立了甲型H1N1流感疫苗中NA含量双抗体夹心ELISA检测方法,该法具有良好的线性及灵敏度,准确度和精密度高,能满足甲型H1N1流感疫苗NA含量的检测需求。     

利用EXCEL快速进行毒力测定中的致死中量计算和卡方检验

根据机率值分析法和最小二乘法的原理 ,在Windows 98 Me 2 0 0 0 XP系统中 ,利用EXCEL软件编制了 2个杀虫剂毒力测定中计算有关毒力回归方程、LD50 、相关系数、LD50 的 95 %置信限、标准误以及卡平方检验等计算程序模板。计算时只需要输入试验浓度 (或剂量 )、试虫数和试虫死亡数 ,即可快速、简便、准确计算毒力测定的结果 ,并进行卡平方值的计算和适合性判断。     

甲型H1N1流感疫苗神经氨酸酶含量测定参考品的建立

目的建立甲型H1N1流感疫苗神经氨酸酶含量测定参考品。方法对甲型H1N1流感疫苗原液进行还原电泳后,采用免疫印迹,糖蛋白染色,方法初步确定甲流H1N1疫苗原液中神经氨酸酶SDS-PAGE条带位置,切取条带后通过edman N端测序法进行确认。采用Lowry法进行总蛋白定量,SDS-PAGE密度扫描的方法确定神经氨酸酶比例,计算出疫苗原液中神经氨酸酶含量。结果确定甲流疫苗原液中神经氨酸酶在SDS-PAGE中相对分子质量约71 000,对多批次疫苗原液进行测定后,选取神经氨酸酶含量较高的批次进行测定,总蛋白质量浓度为1046.00μg/m L,神经氨酸酶质量分数11.78%。二者相乘得出该批次疫苗原液神经氨酸酶含量为123.22μg/m L。结论研究成功建立了甲型H1N1流感疫苗神经氨酸酶含量测定参考品,其他毒株生产的流感疫苗也可以参考该方法建立NA含量测定参考品。     

用于快速测定流感疫苗效力的新型抗体非依赖性受体结合SPR检测法

<正>2009年H1N1流感大流行之后世界卫生组织举办研讨会,提出优先开发测定流感疫苗效力的替代检测方法,以期满足流感大流行时加快流感疫苗批签发的需求。作者开发了一种抗体非依赖性的,简单的高通量的以受体结合SPR为基础的效力检测法,这种方法不需要任何参考抗血清,而且能够用于快速血凝素定量测定以及在流感大流行情况下便于流感疫苗的快速批签发。在这种受体结合SPR表面等离振共振测定中,利用在α-2,6或者在α-2,3     

应用指示剂提高生长谱法测定发酵液中L—苏氨酸含量的准确性

在应用生长谱法测定发酵液中L—苏氨酸含量时,增强培养基上指示菌生长圈的清淅度,提高检测的准确性,是苏氨酸发酵上的一个重要方面。我们在测定培养基中添加一定量的溴甲酚紫,结晶紫或两者的混合物,生长圈清淅可见。在L—苏氨酸一定浓度范周内,生长圈的大小与L—苏氨酸的含量成线性关系。与传统纸层析测定法相比有更高的准确性。本文就添加指示剂的浓度、培养条件、指示菌浓度等因素进行了叙述。     

四苯硼钠容量法测定谷氨酸钾注射液钾含量

目的:研究建立四苯硼钠容量法测定谷氨酸钾注射液中钾离子含量的方法.方法:分别采用四苯硼钠容量法与四苯硼钠重量法测定谷氨酸钾注射液中钾的含量,并比较其测定结果.结果:四苯硼钠容量法平均加样回收率为102.50%(RSD=0.41%,n=9),与四苯硼钠重量法所测得的结果进行t检验,结果无显著性差异.结论:四苯硼钠容量法简便、快速、准确,可替代四苯硼钠重量法快速测定谷氨酸钾注射液中钾的含量.     

流感病毒A/PR/8/34重配母本株高免疫原性HA蛋白制备及鉴定

制备流感病毒经典重配过程中所需的A/PR/8/34母本株血凝素蛋白(Hemagglutinin,HA)抗血清。A/PR/8/34流感病毒灭活纯化后经菠萝蛋白酶消化。5%~20%蔗糖连续密度梯度离心法纯化HA蛋白。单向免疫扩散法(Single Radial Immunodiffusion,SRID)筛选目的蛋白。SDS-PAGE法鉴定目的蛋白。纯化的A/PR/8/34 HA蛋白免疫兔子制备抗血清,血凝抑制试验(Hemoglutination Inhibition Assay,HI)测定HA抗血清效价,经SRID法鉴定HA抗血清纯度。成功制备了高免疫原性A/PR/8/34HA蛋白;兔抗血清HI滴度可达10240,SRID法鉴定为高纯度HA抗血清。制备了流感病毒经典重配中关键试剂,摸索成功整套技术方法,为我国自主研发季节性流感疫苗株奠定了基础。     

Application of deglycosylation and electrophoresis to the quantification of influenza viral hemagglutinins facilitating the production of 2009 pandemic influenza (H1N1) vaccines at multiple manufacturing sites in China

The single radial immunodiffusion (SRID) method currently used to determine the hemagglutinin (HA) content of the inactivated influenza vaccines depends on the availability of reference HA antigen and corresponding anti-serum, updated and provided annually by World Health Organization (WHO) collaborative centers. Particularly early in a pandemic outbreak, reference reagents could be the bottleneck in vaccine development and release. Therefore, other reliable tests capable of quantifying HA content could substantially shorten the time needed for vaccine formulation. Here electrophoretic separation of deglycosylated samples in conjunction with densitometry was used to quantify HA contents of H1N1 vaccine at multiple manufacturing sites. We found the overall consistency between the alternative method and traditional SRID was 88–122% in seven lots of vaccine bulks from four subtypes (types) of influenza vaccine, confirming its suitability to quantify HA content. Moreover, we used the alternative method to prepare a national HA antigen reference in China for quality control of 2009 pandemic influenza A (H1N1) vaccines prior to the arrival of the WHO SRID reference standards, subsequently confirming good agreement between both methods. The alternative method for vaccine quantification enabled the Chinese health authority to approve H1N1 vaccine 1 month earlier than otherwise possible.     

The use of the radial hemolysis reaction for demonstrating antibodies to the surface antigens of the influenza virus in assessing postvaccinal immunity

Two serological tests--single radial hemolysis (RSH) and hemagglutination inhibition (HI) were used to evaluate the different techniques (intranasal, intradermal and combined methods) of application of inactivated influenza vaccines. When seroconversion to hemagglutinin (HA) was determined sensitivity of SRH proved to be higher as compared with HI by 6.7-41.4%. This test has also shown that the frequency of the seroconversion to HA was 2.1-5.6 times higher than that to neuraminidase (NA). It is important to standardize both HA and NA components in the influenza vaccine. It is interesting to study the local and cell immunity after intranasal inoculation of influenza vaccine because of the low postvaccinal level of serum antibodies and in connection with some publications concerning the protective role of this immunization method.     

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。     

Immunologic response to the influenza virus neuraminidase is influenced by prior experience with the associated viral hemagglutinin. I. Studies in human vaccinees

Analysis of an earlier study of H3N2 and H7N2 inactivated influenza vaccines in schoolchildren demonstrated a greater viral neuraminidase (NA) immunogenicity of the vaccine containing the H7 hemagglutinin (HA) antigen to which they had not been primed, despite the lesser NA antigen content of that vaccine. Thus, prior experience with the influenza viral HA appeared to have a negative influence on immune response to NA, the associated external glycoprotein, presumably on the basis of intermolecular antigenic competition. In a second study, sequential immunologic response to influenza viral NA was compared in college students who were immunized with either conventional commercial vaccine or an antigenic reassortant H7N1 vaccine, and who subsequently experienced natural infection with an H1N1 influenza virus. Although both vaccines were only marginally immunogenic in inducing NA antibody response in seronegative subjects, in vaccinees initially seropositive for HA antibody significant NA antibody titer increases occurred with H7N1 vaccine. Subsequent natural infection boosted NA antibody less effectively in the population previously primed by natural infection than in initially seronegative subjects primed by H7N1 vaccination. It is suggested that primary immunization monospecific for influenza viral NA may alter the subsequent pattern of immune response to one more favorable to the induction of NA antibody when virus is encountered.     

Titer on Chip: New Analytical Tool for Influenza Vaccine Potency Determination

Titer on Chip (Flu-ToC) is a new technique for quantification of influenza hemagglutinin (HA) concentration. In order to evaluate the potential of this new technique, a comparison of Flu-ToC to more conventional methods was conducted using recombinant HA produced in a baculovirus expression system as a test case. Samples from current vaccine strains were collected from four different steps in the manufacturing process. A total of 19 samples were analysed by Flu-ToC (blinded), single radial immunodiffusion (SRID), an enzyme-linked immunosorbent assay (ELISA), and the purity adjusted bicinchoninic acid assay (paBCA). The results indicated reasonable linear correlation between Flu-ToC and SRID, ELISA, and paBCA, with regression slopes of log-log plots being 0.91, 1.03, and 0.91, respectively. The average ratio for HA content measured by Flu-ToC relative to SRID, ELISA, and paBCA was 83%, 147%, and 81%, respectively; indicating nearly equivalent potency determination for Flu-ToC relative to SRID and paBCA. These results, combined with demonstrated multiplexed analysis of all components within a quadrivalent formulation and robust response to HA strains over a wide time period, support the conclusion that Flu-ToC can be used as a reliable and time-saving alternative potency assay for influenza vaccines.     

密码子优化的人H5N1流感病毒HA基因在哺乳动物细胞中获得高效表达

为了提高人禽流感病毒血凝素HA的表达量,应对流感大流行疫苗的需求,按照人的偏爱密码子将H5N1(A/Anhui/1/2005)流感病毒的HA基因进行优化改造,经全基因合成后插人到真核表达载体pDC315中,构建了真核表达质粒pDC315-Mod.HA;将此质粒和含野生HA基因的真核表达质粒pDC315-Wt.HA分别转染293T细胞,比较HA蛋白的表达量.结果表明:经间接免疫荧光实验及Western blot实验比较和鉴定,密码子优化后,HA蛋白在293T细胞中的表达水平显著提高,为流感大流行疫苗的研究打下了基础.     

Analysis of genome integrity of influenza virus in formaldehyde-inactivated split vaccines

Although inactivated split-virus influenza vaccines are widely used to render protection against the viral infection, information regarding the effects of the vaccine preparation on the integrity of the viral genomes is currently very limited. In the present study, to gain insight into the physical and genetic alterations of RNA viral genomes in the course of the vaccine preparation, we analyzed the influenza virus A H1N1 hemagglutinin (HA) genome segment in a conventional split-virus influenza vaccine inactivated by formaldehyde, which encodes the major surface protein of the virus. The vaccine solutions were treated with proteinase K prior to RNA purification, and viral genomic RNA was successfully retrieved up to almost eightfold higher than samples without the treatment. Despite the high yield, no full-length bands of the influenza viral genomes were identifiable upon electrophoresis due to severe degradation. Interestingly, however, we were able to amplify a variety of genomic regions including a fragment covering the full-length HA gene using cDNA. Furthermore, sequencing of a series of the fragments for confirmation revealed that the rate of base alteration of the gene in the vaccine was approximately 0.1 %, which is comparable to the spontaneous error rate occurring during PCR. We next constructed a GST expression vector carrying the full-length HA fragment cloned from the vaccine and confirmed that the correct size of the expected GST-fused HA protein was expressed. Taken together, these results demonstrate that a full-length HA RNA genome fragment with comparatively intact sequence information may exist in the inactivated split-virus vaccine. Therefore, these experimental findings on the properties of the HA RNA in the influenza vaccine, may contribute to cautious use of the vaccine in a variety of research areas and protocols.     

Bacterial HA1 vaccine against pandemic H5N1 influenza virus: evidence of oligomerization, hemagglutination, and cross-protective immunity in ferrets

The impending influenza virus pandemic requires global vaccination to prevent large-scale mortality and morbidity, but traditional influenza virus vaccine production is too slow for rapid responses. We have developed bacterial systems for expression and purification of properly folded functional hemagglutinin as a rapid response to emerging pandemic strains. A recombinant H5N1 (A/Vietnam/1203/2004) hemagglutinin globular domain (HA1) was produced in Escherichia coli under controlled redox refolding conditions. Importantly, the properly folded HA1(1-320), i.e., HA1 lacking amino acids 321 to 330, contained ≥75% functional oligomers without addition of foreign oligomerization sequence. Site-directed mutagenesis mapped the oligomerization signal to the HA1 N-terminal Ile-Cys-Ile residues at positions 3 to 5. The purified HA1 oligomers (but not monomers) bound fetuin and agglutinated red blood cells. Upon immunization of rabbits, the oligomeric HA1(1-320) elicited potent neutralizing antibodies against homologous and heterologous H5N1 viruses more rapidly than HA1(28-320) containing only monomers. Ferrets vaccinated with oligomeric HA1 (but not monomeric HA1 with the N terminus deleted) at 15 and 3 μg/dose were fully protected from lethality and weight loss after challenge with homologous H5N1 (A/Vietnam/1203/2004, clade 1) virus, as well as heterologous clade 2.2 H5N1 (A/WooperSwan/Mongolia/244/2005) virus. Protection was associated with a significant reduction in viral loads in the nasal washes of homologous and heterologous virus challenged ferrets. This is the first study that describes the presence of an N-terminal oligomerization sequence in the globular domain of influenza virus hemagglutinin. Our findings suggest that functional oligomeric rHA1-based vaccines can be produced efficiently in bacterial systems and can be easily upscaled in response to a pandemic influenza virus threat.     

Chitosan Nanoparticle Encapsulated Hemagglutinin-Split Influenza Virus Mucosal Vaccine

Subunit/split influenza vaccines are less reactogenic compared with the whole virus vaccines. However, their immunogenicity is relatively low and thus required proper adjuvant and/or delivery vehicle for immunogenicity enhancement. Influenza vaccines administered intramuscularly induce minimum, if any, mucosal immunity at the respiratory mucosa which is the prime site of the infection. In this study, chitosan (CS) nanoparticles were prepared by ionic cross-linking of the CS with sodium tripolyphosphate (TPP) at the CS/TPP ratio of 1:0.6 using 2 h mixing time. The CS/TPP nanoparticles were used as delivery vehicle of an intranasal influenza vaccine made of hemagglutinin (HA)-split influenza virus product. Innocuousness, immunogenicity, and protective efficacy of the CS/TPP-HA vaccine were tested in influenza mouse model in comparison with the antigen alone vaccine. The CS/TPP-HA nanoparticles had required characteristics including nano-sizes, positive charges, and high antigen encapsulation efficiency. Mice that received two doses of the CS/TPP-HA vaccine intranasally showed no adverse symptoms indicating the vaccine innocuousness. The animals developed higher systemic and mucosal antibody responses than vaccine made of the HA-split influenza virus alone. The CS/TPP-HA vaccine could induce also a cell-mediated immune response shown as high numbers of IFN-γ-secreting cells in spleens while the HA vaccine alone could not. Besides, the CS nanoparticle encapsulated HA-split vaccine reduced markedly the influenza morbidity and also conferred 100% protective rate to the vaccinated mice against lethal influenza virus challenge. Overall results indicated that the CS nanoparticles invented in this study is an effective and safe delivery vehicle/adjuvant for the influenza vaccine.