贵州白纹伊蚊对登革病毒易感性的研究

目的 用细胞、分子生物学技术进行贵州省白纹伊蚊不同地理株对登革病毒(DEN)易感性的研究。方法 采集贵州省9个地(州)市共计15个县(区)白纹伊蚊幼虫标本，饲养为成蚊；取羽化后3～5日龄期的贵州不同地理株白纹伊蚊，用不同型别的DEN分别经口连续感染3d，于首次感染后的4、7、10、14d收集感染成蚊标本；制备蚊悬液，碘化钠法提取RNA，用DENNS1基因区通用引物经逆转录．聚合酶链反应(RT-PCR)检测DEN核酸；蚊悬液接种C6／36细胞进行病毒分离，制作细胞抗原片，经间接免疫荧光法检测DEN抗原；同时感染白纹伊蚊海南株作为对照。结果 DEN1-4型国际参考株感染白纹伊蚊贵州省不同地方株，其感染比率分别为12／15、12／15、8／15和13／15。结论 白纹伊蚊贵州省不同地方株对DEN1-4型国际参考株普遍易感，表明贵州省具备引起登革热流行的条件。     

4型腺病毒载体的构建和β－半乳糖苷酶基因的表达

以４型腺病毒疫苗株感染Ａ５４９细胞，提取病毒ＤＮＡ，将ＥｃｏＲＩ消化的Ｄ片段（７０．５－８３．０基因图谱单位）克隆入ｐＵＣ１８质粒，得ｐＡｄ４（７０．５－８３）质粒，质粒ｐＡｄ４（７０．５－８３）和ｐＡｄ４Ｃ１－２５经酶切、系列亚克隆、加接头等方法得到大部分和部分缺失Ｅ３区的重组质粒。聚合酶链反应（ＰＣＲ）法获得ｐｏｌｙ（Ａ），构建约８００ｂＰ腺病毒晚期表达盒，在所构建的腺病毒重组质粒Ｅ３缺失区或Ｅ４与ＩＴＲ间插入表达盒，得到可同时表达２个或２个以上外源基因和保留了Ｅ３区编码分子量为１９３００糖蛋白基因的３种Ａｄ４载体。将ｌａｃＺ基因插入载体表达区，与Ｂｅｌｌ消化的Ａｄ４ＤＮＡＡ片段共转染Ａ５４９细胞，ＯＮＰＧ法检测证实所构建的载体和表达盒功能良好。本项工作对于在国内研究口服活疫苗及开展基因治疗均具有重要意义。     

Vector-based genetically modified vaccines: Exploiting Jenner’s legacy

The global vaccine market is diverse while facing a plethora of novel developments. Genetic modification (GM) techniques facilitate the design of ’smarter’ vaccines. For many of the major infectious diseases of humans, like AIDS and malaria, but also for most human neoplastic disorders, still no vaccines are available. It may be speculated that novel GM technologies will significantly contribute to their development. While a promising number of studies is conducted on GM vaccines and GM vaccine technologies, the contribution of GM technology to newly introduced vaccines on the market is disappointingly limited.In this study, the field of vector-based GM vaccines is explored. Data on currently available, actually applied, and newly developed vectors is retrieved from various sources, synthesised and analysed, in order to provide an overview on the use of vector-based technology in the field of GM vaccine development. While still there are only two vector-based vaccines on the human vaccine market, there is ample activity in the fields of patenting, preclinical research, and different stages of clinical research. Results of this study revealed that vector-based vaccines comprise a significant part of all GM vaccines in the pipeline. This study further highlights that poxviruses and adenoviruses are among the most prominent vectors in GM vaccine development.After the approval of the first vectored human vaccine, based on a flavivirus vector, vaccine vector technology, especially based on poxviruses and adenoviruses, holds great promise for future vaccine development. It may lead to cheaper methods for the production of safe vaccines against diseases for which no or less perfect vaccines exist today, thus catering for an unmet medical need. After the introduction of Jenner’s vaccinia virus as the first vaccine more than two centuries ago, which eventually led to the recent eradication of smallpox, this and other viruses may now be the basis for constructing vectors that may help us control other major scourges of mankind.     

Live porcine reproductive and respiratory syndrome virus vaccines: Current status and future direction

Porcine reproductive and respiratory syndrome (PRRS) caused by PRRS virus (PRRSV) was reported in the late 1980s. PRRS still is a huge economic concern to the global pig industry with a current annual loss estimated at one billion US dollars in North America alone. It has been 20 years since the first modified live-attenuated PRRSV vaccine (PRRSV-MLV) became commercially available. PRRSV-MLVs provide homologous protection and help in reducing shedding of heterologous viruses, but they do not completely protect pigs against heterologous field strains. There have been many advances in understanding the biology and ecology of PRRSV; however, the complexities of virus-host interaction and PRRSV vaccinology are not yet completely understood leaving a significant gap for improving breadth of immunity against diverse PRRS isolates. This review provides insights on immunization efforts using infectious PRRSV-based vaccines since the 1990s, beginning with live PRRSV immunization, development and commercialization of PRRSV-MLV, and strategies to overcome the deficiencies of PRRSV-MLV through use of replicating viral vectors expressing multiple PRRSV membrane proteins. Finally, powerful reverse genetics systems (infectious cDNA clones) generated from more than 20 PRRSV isolates of both genotypes 1 and 2 viruses have provided a great resource for exploring many innovative strategies to improve the safety and cross-protective efficacy of live PRRSV vaccines. Examples include vaccines with diminished ability to down-regulate the immune system, positive and negative marker vaccines, multivalent vaccines incorporating antigens from other porcine pathogens, vaccines that carry their own cytokine adjuvants, and chimeric vaccine viruses with the potential for broad cross-protection against heterologous strains. To combat this devastating pig disease in the future, evaluation and commercialization of such improved live PRRSV vaccines is a shared goal among PRRSV researchers, pork producers and biologics companies.     

Gene and antisense delivery in alcoholism research

This article represents the proceedings of a symposium at the 2001 annual meeting of the Research Society on Alcoholism in Montreal, Canada. Drs. Yedy Israel and Fulton Crews were organizers and co-chairpersons. The presentations were (1) Introduction to the symposium, by Yedy Israel; (2) Gene delivery to the brain, by Fulton T. Crews; (3) Gene therapy in alcoholic liver injury, by Ronald Thurman; and (4) Antisense oligonucleotides and antisense-gene delivery, by Yedy Israel.     

构建不同筛选特性的HBV X基因真核表达载体

目的:构建不同筛选特性的两个HBV X基因真核表达载体.方法:从质粒pEcob6中PCR扩增HBV X全基因,利用pCEP4和pcDNA3.1( )两者多克隆位点的特点,选用pGEM(R)-T Easy Vector构建中间载体pEasy-X,分别酶切后连接特异性片段构建载体pCEP4-X和pcDNA3.1( )-X.结果:从质粒pEcob6成功PCR扩增出HBV X全基因并克隆至质粒pEasy-X,酶切、PCR及测序均证实真核表达载体质粒pCEP4-X和pcDNA3.1( )-X构建成功.结论:具有不同筛选特性的两个HBVX基因真核表达载体业已成功构建.     

海南三亚农村人居环境整治成效与病媒生物种群密度的相关性

目的 调查海南三亚农村重要病媒生物的种群密度,分析其密度变化与农村人居环境整治成效的相关性。方法 于2019年6—11月,参考国家相关标准,对三亚市4个行政区和1个生态区管委会分别随机选取自然村或农场队的公共区域、农户庭院和房前屋后以目测法调查蚊幼孳生地、蚊幼阳性积水、成蚊数,蝇类孳生地、成蝇数,鼠类栖息地、鼠迹数及蟑迹数。结合该自然村或农场队的人居环境评分,分析其与病媒生物种群密度的相关性。结果 共调查三亚市163个自然村/农场队次的病媒生物种群数量,其中成蝇数（15.82±22.24）只、蝇孳生地数（4.45±3.21）处的种群数量相对较大,其次是鼠类栖息地数（2.97±6.58）处、鼠迹数（2.79±2.88）只和成蚊数（1.69±6.40）只、蚊孳生地数（2.87±2.53）处、阳性积水数（2.33±2.82）处,蜚蠊蟑迹数（0.16±0.48）只数量较少。从6—11月,病媒生物种群数量整体呈下降趋势。而蝇类孳生地数未见明显改变,鼠迹数和鼠类栖息地数量先下降后上升。本研究观察到三亚农村的病媒生物孳生和栖息地类型很多,具有明显的热带地方特色。相关性分析显示,三亚市农村蚊幼孳生地数、蝇类孳生地、成蝇数、鼠迹数与整治成效,在5个月中呈负相关关系;本研究调查的病媒生物种群数量的8个指标中,除蝇类孳生地和鼠类栖息地外（P>0.05）,蚊幼孳生地（P<0.01）、蚊幼阳性积水（P=0.04）、成蚊数量（P=0.01）、成蝇数量（P<0.01）、鼠迹数（P=0.04）和蟑迹数（P=0.04）在农村人居环境和村庄清洁整治后,均有明显降低。结论 三亚农村环境中的病媒生物种群密度高,通过农村人居环境整治,病媒生物种群密度明显下降。     

逆转MDR-1小干扰RNA的慢病毒载体系统的构建和鉴定

目的 构建并鉴定表达MDR-1小干扰RNA的慢病毒载体系统并检测其对于喉癌多药耐药细胞系(LSC-1/TAX)多药耐药表型的逆转效果.方法 根据MDR-1基因序列,设计3条寡聚核苷酸序列,合成互补DNA链,插入慢病毒表达质粒pLVTHM中,与pCMV-dR8.74和pMD2G共转染293T细胞,包装产生病毒颗粒.以RT-PCR、realtime PCR及Western blot方法检测三条siRNA在人喉癌耐药细胞系(LSC-1/TAX)中的干扰效率,并采用MTT方法检测干扰前后化疗药物的敏感性.结果 通过酶切和测序证实慢病毒载体构建正确,产生能够表达GFP和siRNA的慢病毒颗粒,浓缩滴度为＞1×108TU/ml.三条siRNA均可以感染LSC-1/TAX细胞系,其中第三条siRNA敲减效果最佳.结论 成功建立逆转MDR-1小干扰RNA的慢病毒载体系统,为逆转喉癌多药耐药表型的实验奠定了基础.     

HCV非结构蛋白3真核表达载体pcDNA3.1(-)/NS3的构建

目的：构建HCV NS3基因真核表达载体，为进一步研究和解析HCV NS3基因诱发不死化人肝细胞癌化的机制准备了条件。方法：将含HCV全长基因的pBRTM/HCV1-3011质粒转化感受态菌JM109并扩增；提取pBRTM/HCV1-3011质粒；从pBRTM/HCV1-3011质粒中PCR扩增出HCV NS3片段；并将其插入到克隆载体pMD18-T中，再与表达载体pcDNA3.1(-)重组，以得到重组的真核表达载体pcDNA3.1(-)/NS3；最后限制性酶切鉴定HCV NS3表达载体。结果：从pBRTM/HCV1-3011质粒中扩增出的HCV NS3片段大小正确，经测序证明其碱基序列为编码目的基因的正确序列；凝胶电泳结果证明已将此片段克隆到pcDNA3.1/NS3内。结论：成功地构建了HCV NS3基因的真核表达载体pcDNA3.1(-)/NS3。     

Virally mediated gene transfer to the vasculature

Gene transfer technology provides valuable tools for the study of vascular biology. By using gene transfer, effects of specific gene products can be evaluated in a highly selective manner. In recent years, techniques used for gene transfer have been adapted for applications to blood vessels, including microvessels, both in vitro and in vivo. The purpose of this review is to provide a survey of published work in this field of investigation and to discuss advantages and limitations of current methods used for gene transfer to the vasculature.