进口轮状病毒疫苗RotaTeq的热稳定性

目的分析进口轮状病毒(rotavirus,RV)疫苗RotaTeq(RV5)的热稳定性。方法采用荧光定量PCR法分别测定22～25和37℃条件下放置不同时间的RV5疫苗滴度,以参考疫苗株滴度为标准,计算RV5疫苗5个型别毒株(G1、G2、G3、G4、P1)滴度和总滴度。同时扩增RV5疫苗G3型毒株的VP7序列,并与GenBank中登录的原型病毒株r G3的VP7序列进行比较。结果 22～25℃条件下,G1、G2、G3、G4、P1型毒株滴度和总滴度每天下降速度分别为3. 51%、2. 26%、3. 19%、5. 22%、3. 18%和3. 61%,各型别毒株间差异无统计学意义(P 0. 05);37℃条件下,G3型毒株滴度的下降速度(31. 20%/h)明显高于其他型别毒株(G1、G2、G4、P1下降速度分别为每小时0. 75%、0. 31%、1. 08%和2. 07%),差异有统计学意义(P 0. 05)。G3型毒株滴度于37℃的半衰期仅为0. 07 d,其原型株rG3的半衰期可达2. 10 d。RV5疫苗G3型疫苗株与其原型株的差异包括散在的氨基酸差异(F32L、T69A、L83F、I118T、D151G、P275L)及位于5′UTR(T25C)和3′UTR(G1041A、A1045G、G1046A、G1047A、C1048T、A1053T)较聚集的核苷酸差异。结论 RV5疫苗中各型别毒株在22～25℃时热稳定性良好,但在37℃时G3型疫苗株是影响RV5疫苗热稳定性的关键,位于VP7 UTR的核苷酸突变可能是导致其热稳定性降低的主要原因。     

基于轮状病毒VP6蛋白新型候选疫苗的研发进展

轮状病毒(rotavirus,RV)是一种人畜共患病原体,给畜牧业和人类健康带来巨大威胁。对RV感染的治疗,目前尚无有效药物,接种疫苗是有效防控RV性胃肠炎暴发的重要措施。目前人商品化RV疫苗均为口服减毒活疫苗,存在散毒风险及潜在安全性等问题,且该疫苗在不发达国家的免疫效力较低,因此,非复制型疫苗很可能成为主要的候选疫苗。本文以RV结构蛋白VP6为基础,对该蛋白在RV免疫应答中的作用及其在RV非复制型疫苗的研发及防治中的应用作一综述。     

悬浮Vero细胞快速扩增轮状病毒

目的探讨在悬浮Vero细胞中快速扩增轮状病毒(RV)的方法。方法 Vero细胞经消化后,直接接种KMG1b7株RV。采用微量滴定法、PAGE和RT-PCR等方法比较悬浮扩增、静置培养及微载体发酵培养RV的感染性滴度、基因组核酸带型和型特异VP7基因序列;采用电镜观察和Westernblot鉴定悬浮扩增RV的形态及结构蛋白的抗原性。结果悬浮细胞扩增的RV接种24h后病毒感染性滴度达峰值,为6.00lgCCID50/ml;而静置培养和微载体发酵培养分别在接种后(96±24)h和(48±6)h达峰值,分别为(6.00±0.25)lgCCID50/ml和(6.50±0.25)lgCCID50/ml。悬浮扩增的RV基因组呈典型的4-2-3-2G1血清型带型,G1型特异基因VP7序列未发生突变。悬浮扩增的RV形态和结构蛋白的抗原性未发生改变。结论在悬浮Vero细胞中扩增RV可以缩短病毒制备周期,提高病毒收获量,有利于RV疫苗的研制或生产。     

轮状病毒疫苗的研究进展

轮状病毒(Rotavirus,RV)是世界范围内引起婴幼儿腹泻的主要病原体。RV疫苗的研制工作已取得了很大进展,但仍存在较大缺陷。目前投入使用的3种RV疫苗虽然能够对重症腹泻起到良好的保护作用,但却不能很好地预防RV感染,因此继续研制新的RV疫苗十分重要。本文对RV及RV疫苗的研究进展作一综述。     

我国流行的4株狂犬病街毒株G基因序列及分子流行病学研究

目的探讨我国流行的狂犬病毒(RV)基因差异,评价现有疫苗的适用性。方法通过RT-PCR并对其产物测序后获得4株RV街毒株的G基因序列以及G与M和L基因的区间序列。利用计算机分析软件比较4株RV与已经发表的毒株的核苷酸和推导的氨基酸序列。结果糖蛋白(GP)完整的编码基因序列长度为1575 bp。GP氨基酸序列同源性明显高于相应的核苷酸序列(除Mokola外),4株街毒与CTN的同源性高于aG株。GP不同区段比较显示,膜外区同源性高于膜内区。G-M区间核苷酸序列长度为5 bp;除广西4外,其余毒株100％同源。GL区间核苷酸序列长度为2,4 bp,越1与肥东同源性为100％。结论4株RV均属于基因I型。广西的毒株之间存在不同的来源。街毒与疫苗株之间基因存在差异。4株RV与SAD-B19进化途径相近,与PV株相差较远。越1与肥东株亲缘关系极近,可能是由同一毒株演化而来。     

灭活轮状病毒疫苗与灭活脊髓灰质炎病毒疫苗联合使用免疫效果评价

目的评价灭活轮状病毒疫苗(inactivated rotavirus vaccine,IRV)与灭活脊髓灰质炎病毒疫苗(inactivated poliovirus vaccine,IPV)免疫大鼠后,两种疫苗间免疫效果的相互作用。方法将Wistar大鼠随机分成联合免疫组、间隔免疫组和单疫苗免疫组:联合免疫组接种IPV后4周,经双侧腿同时免疫IPV和IRV,共2次,间隔4周;单疫苗免疫组2组,分别免疫3针IPV和2针IRV,每针均间隔4周;间隔免疫组免疫1针IPV后4周,开始进行IPV和IRV间隔免疫(每针间隔2周,共6周)。分别于每次免疫后4周经尾静脉采血,分离血清,采用微量中和试验结合免疫荧光抑制方法检测血清抗RV中和抗体水平,ELISA法检测血清抗RV特异性Ig G抗体水平,微量中和试验法检测血清抗脊髓灰质炎病毒中和抗体水平。结果大鼠经2针IRV免疫后,血清抗RV中和抗体和特异性Ig G抗体几何平均滴度(geometric mean titer,GMT)均明显上升,血清抗体阳转率均达100%;经3针IPV免疫后,Ⅰ、Ⅱ、Ⅲ型脊髓灰质炎病毒中和抗体GMT均明显上升,抗体阳转率均达100%;联合免疫组、间隔免疫组和单疫苗免疫组间血清抗RV中和抗体水平、特异性Ig G抗体水平及抗脊髓灰质炎病毒中和抗体水平差异无统计学意义(P>0.05)。结论 IRV和IPV免疫大鼠后均获得到良好的免疫效果,两种疫苗联合使用时,免疫效果无相互干扰作用。     

狂犬病病毒PV-2061株基因序列测定及其抗原性和免疫原性分析

目的测定狂犬病病毒(rabies virus,RV)PV-2061株全基因组序列,并分析其抗原性及免疫原性。方法 RTPCR法对RV PV-2061株基因组进行分段扩增,分别克隆至p MD18-T Simple Vector,转化感受态E.coli TOP10,挑取阳性克隆,进行测序。应用DNAstar Meg Align软件对测序结果进行拼接和分析;ELISA法检测PV-2061株的抗原性;用主种子批毒种制备的原疫苗免疫小属,检测PV-2061株的免疫原性。结果 RV PV-2061株的基因组全长11 932 bp,由3′端至5′端依次排列着N、P、M、G、L 5个结构基因,每个基因由3′端到5′端的非编码区及中间的编码区构成。与Gen Bank中已知全基因组序列的毒株比较,基因组前端3′先导序列和N基因的非编码区均无长度变化,从P基因开始,基因非编码区的长度开始出现差异,导致各毒株基因组长度不同。RV PV-2061株的抗原值为7.46 IU/ml;主种子批毒种制备原疫苗保护指数为1 585。结论确定RV PV-2061株全基因组序列为基因1型,且具有RV特有的抗原性和良好的免疫原性,为狂犬病疫苗的设计和毒株的筛选提供了实验依据。     

湘潭县和融水县2岁以下婴幼儿轮状病毒腹泻病流行病学调查

目的通过对监控区域内腹泻病例的监测,获取轮状病毒(rotavirus,RV)腹泻发生率。方法在广西壮族自治区融水县、湖南省湘潭县两个地区的村卫生室及乡镇卫生院中开展腹泻监测,收集腹泻病例和流行病学信息,采集病例粪便样本。应用ELISA法检测RV,RT-PCR法对其进行基因分型。结果湘潭县和融水县RV腹泻高峰主要集中在2月份,分别占总数的45. 9%和53. 9%;两地腹泻发病率为285. 1/(1 000人·年),RV检出率为18. 0%,RV腹泻发病率为51. 2/(1 000人·年);湘潭县和融水县的轮状病毒血清型均以G9型(分别占58. 7%和73. 7%)和P8型为主(分别占67%和81. 6%)。结论 RV是导致2岁以下婴幼儿腹泻的常见病原体,湘潭和融水县的RV流行株均为G9型和P8型,流行高峰为2月。     

轮状病毒LLR疫苗株VP7基因的遗传变异研究

目的研究轮状病毒(RV)LLR疫苗株VP7基因的遗传特征,为疫苗的质量控制和发展提供依据。方法将LLR株轮状病毒毒种LLR38在原代牛肾细胞上连续传至49代。提取第38、43、44、49代病毒RNA。通过RT-PCR扩增VP7基因片段,将其克隆入质粒pGEM-T中,进行序列测定与分析。结果LLR株VP7基因全长1062bp,含编码326个氨基酸的单一的开放读码框架(ORF)。各代次病毒的VP7基因核苷酸与推导的氨基酸变化完全一致,与GenBanK中LLR参考株(L11602)同源性分别为99.9%和99.7%。与14株G10血清型RV毒株之间,核苷酸与推导的氨基酸序列同源性分别为84.3%～87.4%和92.7%～94.9%;与不同血清型RV代表株间,VP7基因核苷酸与推导的氨基酸同源性分别为62.2%～76.8%和72.9%～83.1%;在A、B、C3个重要抗原表位,LLR株与同一血清型RV代表株B223氨基酸同源性高达97.5%,而与不同血清型仅为42.5%～62.5%。结论轮状病毒LLR疫苗株VP7基因具有良好的遗传稳定性,与来自不同国家同一型别的RV株VP7蛋白氨基酸序列之间无明显差异,在遗传上密切相关,从VP7基因分子水平证明LLR株毒种及其制备的疫苗是安全可靠的。     

重庆地区5岁以内儿童腹泻病毒病原及流行病学特点

目的了解重庆地区5岁以内儿童腹泻病毒病原及流行病学特点。方法收集重庆医科大学附属儿童医院2010年8～11月就诊的5岁以内腹泻患儿的粪便标本共500份,采用胶体金法检测A组轮状病毒(Rotavirus,RV),RT-PCR法检测B、C组RV、诺如病毒(Norovirus,NV)GⅠ和GⅡ、肠道腺病毒(Adenovirus,ADV)、札如病毒(Sapovirus,SLV)和星状病毒(Astrovirus,ASV),取NV和SLV阳性PCR产物测序,并对病毒基因进行分型。采用MEGA 5.05软件构建进化树,Kimura’s two-parameter法计算遗传距离,邻接法(Neighbor-joining)boot-strap重复检验1 000次。结果 500份标本中,检测到A组RV阳性标本134份,阳性率为26.8%;NV GⅡ型阳性标本132份,阳性率为26.4%;ADV阳性标本31份,阳性率为6.2%;SLV阳性标本9份,阳性率为1.8%;ASV阳性标本1份,阳性率为0.2%;未检测到B、C组RV和NV GⅠ型。随机选择22份NV阳性标本进行测序及基因分型,其中GⅡ/4占绝对优势,其次为GⅡ/6、GⅡ/2、GⅡ/3和GⅡ/7。SLV可分为4个基因亚型,其中GⅠ/1为优势株,其次为GⅠ/2、GⅡ/1和GⅠV 1。结论重庆地区5岁以下儿童腹泻以病毒感染为主,RV是主要的病原体,其次为NV、ADV、SLV和ASV。     

抗轮状病毒LLR株G10血清型特异性单克隆抗体的制备与鉴定

目的制备抗轮状病毒(RV)LLR株G10血清型特异性单克隆抗体,并鉴定其特性。方法以纯化的RVLLR株(血清型为G10)为抗原免疫BALB/c小鼠,应用杂交瘤细胞技术筛选分泌G10血清型特异性单抗的杂交瘤细胞株。采用层析法纯化单抗,常规免疫学方法鉴定单抗的特性。结果经筛选获得5G5、1H1和7F6共3株可稳定分泌高效价且具有G10血清型特异性单抗的杂交瘤细胞株。3株细胞分泌的单抗分别为IgG2a/κ、IgG2a/κ和IgG1/κ型;腹水效价均可达1.024×106;分别识别两个抗原位点;相对亲和力依次为1H1﹥7F6﹥5G5;5G5和1H1(细胞上清)均与G1～G4和G6血清型RV抗原无交叉反应;3株杂交瘤细胞分泌的单抗均识别相对分子质量约为34000的VP7蛋白,且均有不同程度的中和活性。结论已成功制备了抗RVLLR株G10血清型特异性单抗,该单抗可用于G10血清型RV的分型检测或LLR毒株的鉴别。     

Genetic Deficiency and Pharmacological Stabilization of Mast Cells Ameliorate Pressure Overload-Induced Maladaptive Right Ventricular Remodeling in Mice

Although the response of the right ventricle (RV) to the increased afterload is an important determinant of the patient outcome, very little is known about the underlying mechanisms. Mast cells have been implicated in the pathogenesis of left ventricular maladaptive remodeling and failure. However, the role of mast cells in RV remodeling remains unexplored. We subjected mast cell-deficient WBB6F1-KitW/W-v (Kit^W/Kit^W-v) mice and their mast cell-sufficient littermate controls (MC^+/+) to pulmonary artery banding (PAB). PAB led to RV dilatation, extensive myocardial fibrosis, and RV dysfunction in MC^+/+ mice. In PAB Kit^W/Kit^W-v mice, RV remodeling was characterized by minimal RV chamber dilatation and preserved RV function. We further administered to C57Bl/6J mice either placebo or cromolyn treatment starting from day 1 or 7 days after PAB surgery to test whether mast cells stabilizing drugs can prevent or reverse maladaptive RV remodeling. Both preventive and therapeutic cromolyn applications significantly attenuated RV dilatation and improved RV function. Our study establishes a previously undescribed role of mast cells in pressure overload-induced adverse RV remodeling. Mast cells may thus represent an interesting target for the development of a new therapeutic approach directed specifically at the heart.     

轮状病毒检测技术的研究进展

轮状病毒是引起婴幼儿病毒性腹泻最常见的病原体,对轮状病毒进行快速、准确的检测,对轮状病毒感染的病原学、流行病学研究以及疫苗的研制和治疗效果评价均有重要意义。本文就轮状病毒检测技术的最新研究进展作一综述。     

Structure-Based Reverse Vaccinology Failed in the Case of HIV Because it Disregarded Accepted Immunological Theory

Two types of reverse vaccinology (RV) should be distinguished: genome-based RV for bacterial vaccines and structure-based RV for viral vaccines. Structure-based RV consists in trying to generate a vaccine by first determining the crystallographic structure of a complex between a viral epitope and a neutralizing monoclonal antibody (nMab) and then reconstructing the epitope by reverse molecular engineering outside the context of the native viral protein. It is based on the unwarranted assumption that the epitope designed to fit the nMab will have acquired the immunogenic capacity to elicit a polyclonal antibody response with the same protective capacity as the nMab. After more than a decade of intensive research using this type of RV, this approach has failed to deliver an effective, preventive HIV-1 vaccine. The structure and dynamics of different types of HIV-1 epitopes and of paratopes are described. The rational design of an anti-HIV-1 vaccine is shown to be a misnomer since investigators who claim that they design a vaccine are actually only improving the antigenic binding capacity of one epitope with respect to only one paratope and not the immunogenic capacity of an epitope to elicit neutralizing antibodies. Because of the degeneracy of the immune system and the polyspecificity of antibodies, each epitope studied by the structure-based RV procedure is only one of the many epitopes that the particular nMab is able to recognize and there is no reason to assume that this nMab must have been elicited by this one epitope of known structure. Recent evidence is presented that the trimeric Env spikes of the virus possess such an enormous plasticity and intrinsic structural flexibility that it is it extremely difficult to determine which Env regions are the best candidate vaccine immunogens most likely to elicit protective antibodies.     

狂犬病病毒4aG株G蛋白基因的克隆及其生物信息学分析

目的克隆狂犬病病毒(Rabies virus,RV)4aG株G蛋白基因,并与其他疫苗毒株G蛋白基因序列进行比较,为我国狂犬病疫苗的研制提供理论依据。方法从RV 4aG株中扩增G蛋白基因,并进行序列测定,利用生物信息学软件绘制系统进化树,预测G蛋白功能位点、二级结构和B细胞抗原表位,并与其他疫苗毒株进行比较。结果克隆的4aG株G蛋白基因序列与GenBank中登录的序列一致。进化树分析显示,4aG株与CVS株的进化关系较远;4aG、4aGV18、CVS、PV及RC-HL毒株跨膜区域在第460～479氨基酸之间,其他毒株在459～478氨基酸之间;PV株有5个糖基化位点,RV-97株有3个糖基化位点,其他毒株均有4个糖基化位点;G蛋白抗原表位位于氨基酸100～300及480～520之间;不同毒株G蛋白抗原位点区域有所不同,与CVS株比较,PV株抗原表位与其最为接近,4aG、4aGV18、CTN-1-31及Flury-HEP株与其抗原表位较为接近。结论4aG株G蛋白功能位点和抗原表位与CVS株相差较大,但其在Vero细胞上传代稳定,可用于制备Vero细胞纯化疫苗。     

Lack of Contribution of p66shc to Pressure Overload-Induced Right Heart Hypertrophy

The leading cause of death in pulmonary arterial hypertension (PAH) is right ventricular (RV) failure (RVF). Reactive oxygen species (ROS) have been suggested to play a role in the development of RV hypertrophy (RVH) and the transition to RVF. The hydrogen peroxide-generating protein p66shc has been associated with left ventricular (LV) hypertrophy but its role in RVH is unclear. The purpose of this study was to determine whether genetic deletion of p66shc affects the development and/or progression of RVH and RVF in the pulmonary artery banding (PAB) model of RV pressure overload. The impact of p66shc on mitochondrial ROS formation, RV cardiomyocyte function, as well as on RV morphology and function were studied three weeks after PAB or sham operation. PAB in wild type mice did not affect mitochondrial ROS production or RV cardiomyocyte function, but induced RVH and impaired cardiac function. Genetic deletion of p66shc did also not alter basal mitochondrial ROS production or RV cardiomyocyte function, but impaired RV cardiomyocyte shortening was observed following PAB. The development of RVH and RVF following PAB was not affected by p66shc deletion. Thus, our data suggest that p66shc-derived ROS are not involved in the development and progression of RVH or RVF in PAH.     

Central Role of Dendritic Cells in Pulmonary Arterial Hypertension in Human and Mice

The pathogenesis of idiopathic pulmonary arterial hypertension (IPAH) is not fully understood, but evidence is accumulating that immune dysfunction plays a significant role. We previously reported that 31-week-old Tnfaip3^DNGR1-KO mice develop pulmonary hypertension (PH) symptoms. These mice harbor a targeted deletion of the TNFα-induced protein-3 (Tnfaip3) gene, encoding the NF-κB regulatory protein A20, specifically in type I conventional dendritic cells (cDC1s). Here, we studied the involvement of dendritic cells (DCs) in PH in more detail. We found various immune cells, including DCs, in the hearts of Tnfaip3^DNGR1-KO mice, particularly in the right ventricle (RV). Secondly, in young Tnfaip3^DNGR1-KO mice, innate immune activation through airway exposure to toll-like receptor ligands essentially did not result in elevated RV pressures, although we did observe significant RV hypertrophy. Thirdly, PH symptoms in Tnfaip3^DNGR1-KO mice were not enhanced by concomitant mutation of bone morphogenetic protein receptor type 2 (Bmpr2), which is the most affected gene in PAH patients. Finally, in human IPAH lung tissue we found co-localization of DCs and CD8+ T cells, representing the main cell type activated by cDC1s. Taken together, these findings support a unique role of cDC1s in PAH pathogenesis, independent of general immune activation or a mutation in the Bmpr2 gene.