Humoral and cell-mediated immune responses to live recombinant BCG-HIV vaccines

Several viral and bacterial live recombinant vaccine vehicles are being developed to produce a new generation of vaccines against a broad spectrum of infectious diseases. The human tuberculosis vaccine Mycobacterium bovis bacillus Calmette-Guerin (BCG) has features that make it a particularly attractive live recombinant vaccine vehicle. BCG and other mycobacteria are highly effective adjuvants, and the immune response to mycobacteria has been studied extensively. With nearly two billion immunizations, BCG has a long record of safe use in man. It is one of the few vaccines that can be given at birth, it engenders long-lived immune responses with only a single dose, and there is a worldwide distribution network with experience in BCG vaccination. Recently developed molecular genetic tools and methods for mycobacteria have provided the means to introduce foreign genes into BCG. Here we report that a variety of human immunodeficiency virus type 1 polypeptides can be expressed in BCG recombinants under the control of the mycobacterial hsp70 promoter and that the foreign polypeptides produced in BCG can induce antibody and T-cell responses. These results demonstrate that BCG can be used as a live recombinant vaccine vehicle to induce immune responses to pathogen proteins produced by the bacillus.     

分枝杆菌重组疫苗rBCG-Sj26GST对小鼠的保护作用

为了研究分枝杆菌重组疫苗rBCG-Sj26GST对小鼠的保护作用,用分枝杆菌重组疫苗rBCG-Sj26GST免疫雄性BALB/c,结核杆菌H37Ra进行攻击,检测小鼠淋巴细胞刺激指数(SI),腹腔巨噬细胞培养上清释放NO量,小鼠血清IFN-γ、IL-2的含量,并计数小鼠肝、肺活细菌数.rBCG-Sj26GST疫苗免疫的小鼠,其脾淋巴细胞刺激指数(SI)为4.12±1.11,与对照组(2.63±0.47)、载体组(1.06±0.08)和BCG组(1.50± 0.41)相比,差异具有显著意义(P＜0.05);rBCG-Sj26GST组巨噬细胞释放的NO量明显高于对照组(P＜ 0.05).小鼠血清IFN-γ的浓度较对照组高33?%,但差异无显著意义(P＞0.05);与载体组相比,差异具有显著意义(P＜0.05).血清白介素-2的浓度较对照组高43?%,较载体组高38?%,但差异无显著意义(P＞ 0.05).经rBCG-Sj26GST免疫的小鼠受结核杆菌攻击后其肺、肝脏结核菌数较对照组少.分枝杆菌重组疫苗rBCG-Sj26GST免疫小鼠后能提高小鼠淋巴细胞刺激指数,刺激IFN-γ、IL-2的分泌,说明此疫苗能诱导CD+4Th1和CD+8CTL的细胞免疫反应,增强小鼠细胞免疫功能,并使小鼠能抵抗结核杆菌的攻击.     

A human recombinant haemoglobin designed for use as a blood substitute.

The need to develop a blood substitute is now urgent because of the increasing concern over blood-transmitted viral and bacterial pathogens. Cell-free haemoglobin solutions and human haemoglobin synthesized in Escherichia coli and Saccharomyces cerevisiae have been investigated as potential oxygen-carrying substitutes for red blood cells. But these haemoglobins cannot be used as a blood substitute because (1) the oxygen affinity in the absence of 2,3-bisphosphoglycerate is too high to allow unloading of enough oxygen in the tissues, and (2) they dissociate into alpha beta dimers that are cleared rapidly by renal filtration, which can result in long-term kidney damage. We have produced a human haemoglobin using an expression vector containing one gene encoding a mutant beta-globin with decreased oxygen affinity and one duplicated, tandemly fused alpha-globin gene. Fusion of the two alpha-globin subunits increases the half-life of this haemoglobin molecule in vivo by preventing its dissociation into alpha beta dimers and therefore also eliminates renal toxicity.     

苧麻脱胶新工艺的研究

用酶及化学法联合脱胶所获得的麻中果胶质量分数为0.103%,半纤维素的质量分数为1.64%,束纤平均断裂强度大于0.567×10-6kg·m-1,新工艺流程短,成本低且脱胶效果良好.     

胞壁形式表达融合蛋白Der p2-PEB1重组BCG的构建和鉴定

利用重组BCG技术,构建能以胞壁形式表达屋尘螨Der p2和PEB1抗原的重组BCG口服哮喘疫苗pCW-Der p2-PEB1-rBCG,以pCW-Der p2质粒和pUC-PEB1质粒DNA为模板扩增基因,构建出重组质粒pCW-Der p2-PEB1.将重组质粒电穿导入BCG感受态细胞,潮霉素抗性筛选rBCG阳性克隆.阳性rBCG经PCR特异性扩增目的基因片段Der p2及PEB1,证实其中含有目的基因.用抗Der p2单克隆抗体和制备的小鼠PEB1抗血清对rBCG进行间接免疫荧光鉴定.结果成功扩增了Der p2及PEB1基因,构建出重组质粒pCW-Der p2-PEB1,并将质粒电穿入BCG中,免疫荧光法鉴定其成功.说明成功地构建了胞壁表达Der p2-PEB1融合蛋白重组BCG pCW-Der p2-PEB1-rBCG.为基因工程疫苗的研制奠定了基础.     

Progress and challenges for malaria vaccines

Malaria causes much physical and economic hardship in tropical regions, particularly in communities where medical care is rudimentary. Should a vaccine be developed, it is the residents of these areas that stand to benefit the most. But the vaccine, which has been promised to be 'just round the corner' for many years, remains elusive. It is important to ask why this is so, when effective vaccines exist for many other infectious diseases. What are the reasons for the slow rate of progress, and what has been learned from the first clinical trials of candidate malaria vaccines? What are the remaining challenges, and what strategies can be pursued to address them?     

Detecting quantitative trait loci for water use efficiency in rice using a recombinant inbred line population

Breeding rice with high water use efficiency (WUE) can ameliorate water shortage through water-saving irrigation.However,WUE is a complex quantitative trait and very few studies have been conducted to measure WUE directly.In this study,a recombined inbred line population derived from a cross between an indica lowland rice and upland japonica rice was used to dissect the genetic control of WUE by fine-monitored water supply experiments.Quantitative trait loci (QTL) were scanned for 10 traits including heading date (HD),water-consumption per day (water/d),shoot weight gain per day (shootw/d),root weight gain per day (rootw/d),kernel weight gain per day (kernelw/d),average WUE at whole plant level (WUEwhole/d),average WUE for up-ground biomass (WUEup/d),average WUE for grain yield (WUEyield/d),average economic index (econindex/d),and average root/shoot ratio per day (ratio/d).The results show that most of the traits were significantly correlated to each other.Twenty-four QTL (LOD ≥ 2.0) were detected for econindex,econindex/d,WUEyield,WUEyield/d,WUEup,WUEup/d,WUEwhole,WUEwhole/d,kernelw,kernelw/d,rootw,and water/d by composite interval mapping.These QTLs are located on chromosomes 1,2,4,6,7,8,and 12.Individual QTLs accounted for 4.97%-10.78% of the phenotypic variation explained.Some of these QTLs overlapped with previously reported drought resistance QTLs detected in this population.These results provide useful information for further dissection of the genetic basis and marker-assisted selection of WUE in rice.     

Generation of a recombinant herpes simplex virus which can provide packaging function for recombinant adeno-associated

The generation of a recombinant HSV (rHSV) that can provide packaging function for rAAV production is described. A set of cosmids including cos48, cos28, cos6, cos14 and cos56, which represents the HSV-1 genome was used for generation of this rHSV. Rep and cap genes of AAV-2 were inserted into Xba Ⅰ site of UL2 gene on cos6, generating cos6-rcΔUL2. After being digested with Pac Ⅰ , cos6-rcΔUL2 and the other 4 cosmids were cotrans-fected into BHK-21 cells. The recombinant virus HSV1-rc/ΔUL2 carrying rep and cap genes was generated due to the homologous recombination of the 5 cosmids. The results showed that the existence of rep and cap genes on this rHSV was stable from passage to passage and the rHSV could support the packaging of rAAV either in cells transiently transfected with AAV vector or in stable cell line harboring AAV vector. Further modification of this rHSV and optimization of conditions involved in rAAV preparation may lead to a large-scale production of rAAV in the near future.     

BCG 65KD热休克蛋白的纯化

目的：研究卡介苗（BCG）65KD热休克蛋白的提纯方法。方法：BCG经37℃恒温振荡培养两周,42℃热休克处理2h,培养液经离心、抽滤、盐析沉淀、SDS-PAGE分离、电泳洗脱等步聚纯化。结果：提纯产物经SDS－PAGE分析,其电泳区带在65KD位置,经抑制试验表明具有较高抗原活性结论：流程方法简单、实用,有助于对IDDM的诊断及其深入研究。     

卡介苗ERP基因缺失突变株免疫原性的研究

为了探究卡介苗ERP基因缺失突变株对小鼠免疫应答的影响,明确敲除ERP基因后是否影响卡介苗的免疫原性,采用卡介苗ERP基因缺失突变株、卡介苗(BCG)及生理盐水背部皮下免疫小鼠,4周、8周、12周、16周后,分别采用CCK8检测脾脏淋巴细胞增殖转化率,ELISA检测淋巴细胞培养上清液IL-2、IFN-γ的产量。结果表明:卡介苗ERP基因缺失突变株组脾淋巴细胞的增殖能力及培养上清液中IL-2I、FN-γ的分泌量均明显高于生理盐水对照组(P<0.01),但与卡介苗组相比无明显差别(P>0.05)。卡介苗ERP基因缺失突变株可引发一定强度的特异性细胞免疫,而此效果与卡介苗相当。     

中红移BCG的X射线性质

最亮团星系(brightest cluster galaxy, BCG)的X射线起源尚不清楚. 射电喷流与径移主导吸积流(advection-dominated accretion flows, ADAF)是2种主要可能的物理起源机制. 2种模型中是否存在主导模型或模型间是否存在关系并不明确, 而且不是所有BCG都存在X射线辐射. 为探究BCG的X射线性质, 进一步了解X射线物理起源机制, 本文选取钱德拉塞卡X射线望远镜(Chandra X-ray observatory, 简称Chandra) 数据存档红移范围0.2相似文献   

一种用存储器实现比较器的方法

介绍了一种实用的双端口存储顺实现比较器的方法,具有容量大,实用性强的特点,并成功地应用于某试验样机。     

HIV感染的治疗性DNA疫苗（综述）

DNA疫苗被称为继完速病原体疫苗和基因工程重组蛋白疫苗后的第3代疫苗,其兼有重组亚单位疫苗的安全性和减毒活疫苗的有效性。HIV感染的防治则以激发细胞免疫为主,以激发细胞免疫为主的DNA疫苗给HIV感染防治带来曙光。目前DNA疫苗在HIV感染防治研究方面已取得显著进展,其临床研究已证明具有明显的刺激机体细胞免疫的效果,尤其是一些细胞因子、趋化因子可明显增强HIV DNA疫苗的免疫反应。就DNA免疫佐剂、HIV病毒基因DNA疫苗作用机制以及加强HIV DNA疫苗的各种调节因素方面的研究进展进行综述,以促进HIV DNA疫苗防治的研究。