抗乙型肝炎表面抗原不同亚型单克隆抗体细胞腺的建立和鉴定

乙型肝炎病毒表面抗原主的的５个不同亚型,是乙肝病毒不同遗传变种表面的表达,通过四次细胞融合获得了抗－ａ、抗－ｄ抗－ｙ、抗－ｗ亚型的单克隆抗体,并作了鉴定及初步应用,为进一步对乙肝亚型分型试剂的研制打下了良好的基础。     

不同感染状态下EB病毒核抗原亚型表达的研究

本实验用免疫印迹法纯化的抗ＥＢＮＡ亚型抗体,结合显微荧光分光光度检测技术,检测在不同感染状态下,三种亚型ＥＢＮＡ抗原在细胞中的表达程度。结果表明,处于潜伏感染状态下的Ｒａｊｉ细胞ＥＢＮＡ－１表达量较大,经巴豆油和正丁酸诱导进入钝挫感染状态后ＥＢＮＡ－１表达减少,而ＥＢＮＡ－２的表达增强。Ｂ＿（９５－８）细胞也有相似的趋势。表明ＥＢ病毒的激活可能与不同ＥＢＮＡ亚型表达量的改变有关。     

大鼠左心房α1受体及其亚型对β受体正性变力效应的影响

本文用放射配体结合实验研究了α１－肾上腺素受体（α１－ＡＲ）及亚型在大鼠左心房的分布。结果表明,大鼠左心房α１－ＡＲ有α１Ａ与α１Ｂ两种亚型,α１Ａ亚型约占１／３,α１Ｂ亚型占２／３。离体灌流左心房功能实验结果表明,α１－ＡＲ不同亚型对β肾上腺素受体（β－ＡＲ）所介导的正性变力反应具有不同性质的协同作用。当酚妥拉明１０μｍｏｌ／Ｌ同时阻断α１Ａ与α１Ｂ亚型时,ＮＥ（同时激动α１－与β－ＡＲ）的剂量－收缩效应曲线显著左移,当用ＣＥＣ２０μｍｏｌ／Ｌ预处理以阻断α１Ｂ亚型时,ＮＥ的剂量－收缩效应曲线则显著右移,而用ＷＢ４１０１１ｎｍｏｌ／Ｌ阻断α１Ａ亚型后,ＮＥ的剂量－收缩效应曲线出现左移;此外,当用苯肾上腺素激动α１－ＡＲ时,异丙肾上腺素的剂量－收缩效应曲线亦显著右移。提示α１Ａ亚型可抑制β－ＡＲ介导的正性变力效应,而α１Ｂ亚型则可增强β－ＡＲ所介导的反应,但当α１－ＡＲ的上述两种亚型同时激动时,则以α１Ａ亚型的调节作用为主。     

佛波酯对A—549细胞株中蛋白激酶C的调节

探讨了佛波酯（ｐｈｏｒｂｏｌ １２－ｍｙｒｉｓｔａｔｅ １３－ａｃｅｔａｔｅ,ＰＭＡ）对人肺癌表皮细胞株Ａ－５４９细胞中数种蛋白激酶Ｃ（ｐｒｏｔｅｉｎ ｋｉｎａｓｅ Ｃ,ＰＫＣ）亚型的调节作用,用蛋白质免疫印迹法在Ａ－５４９细胞中检测到有ＰＫＣ－α、ＰＫＣ－βⅡ、ＰＫＣ－γ、ＰＫＣ－δ和ＰＫＣ－ε等亚型的表达,但未检测到ＰＫＣ－ζ的表达。ＰＭＡ对细胞的短时间处理诱导所有这５种亚型的不同程序的转位（     

基因工程人干扰素α2b和α2a亚型抗病毒效应的实验研究

本文采用鸡胚接种法和微量细胞病变抑制法研究了不同亚型α干扰素（α２ａＩＦＮ和α２ｂＩＦＮ）抗流感病毒、脊髓灰质炎病毒以及麻疹病毒的作用。结果表明：两种亚型α干扰素均显示明显的抗病毒效应,其中（１）α２ｂＩＦＮ抗流感病毒作用略强于α２ａＩＦＮ,（２）两亚型α干扰素抗脊髓灰质炎和麻疹病毒作用相似。     

广西壮族自治区HIV-1流行毒株的基因序列测定和亚型分析

使用ＰＣＲ技术对１４份广西ＨＩＶ－１阳性感染者外周血单核细胞（ＰＢＭＣｓ）样品进行扩增,获得ＨＩＶ－１膜蛋白（ｅｎｖ）基因的核酸片段,并对其Ｃ２－Ｖ３及邻区３５０－４５０个核苷酸序列进行了测定和分析。结果表明,１４份样品中９份为泰国Ｂ（Ｂ′）亚型,５份为Ｅ亚型毒株。其中Ｂ′亚型毒株的基因离散率为４．２％,与Ａ－Ｅ参考亚型及部分Ｂ亚型代表株序列相比较,与包括泰国、缅甸及云南德宏在内的Ｂ亚型毒株序列十分接近,相互之间基因离散率在３．０％－４．４％的范围内;而Ｅ亚型毒株的基因离散率为２．１％,与国际Ｅ亚型毒株的基因离散率最近,为５．６％,与其它国际参考亚型基因离散率很远,在２１．１％－２７．３％。根据以上数据及其它资料提示,广西存在Ｂ′和Ｅ两种亚型的ＨＩＶ－１的流行,且其Ｂ′亚型毒株的传入,与流行在云南德宏州的相同亚型ＨＩＶ－１毒株密切相关,而Ｅ亚型毒株则可能是由泰国经越南传入广西的     

中国不同地区和人群HDV cDNA的筛选、克隆及抗原编码区基因异质性的分析

为研究我国不同地区不同人群中ＨＤＶ毒株的感染分子特征,从我国河南、内蒙、北京、四川、广西、西藏、新疆、辽宁、上海等地的ＨＤＶ健康携带者、慢性丁肝病人与重症肝炎病人中筛选获得１０余份ＨＤＶ－ＲＮＡ阳性血清。经逆转录一多聚酶链反应（ＲＴ－ＰＣＲ）交叉扩增获得ＨＤＶ抗原编码区的ｃＤＮＡ片段并克隆到ＰＧＥＭ－３Ｚｆ（－）或ＰＧＥＭ－Ｔ载体上,经序列分析研究其基因结构特点,结果表明：中国的ＨＤＶ毒株基因型均为Ⅰ型,但至少存在ⅠＡ、ⅠＢ两个亚型,ＨＤＶ毒株在不同地区间存在异质性,其中河南－１、－２、－３株及新疆株与台湾株同源性较高（核苷酸与氨基酸同源性分别大于９２．１％与８６．９％）．当为ⅠＡ型;内蒙－１、四川、广西、西藏－１、辽宁、北京株与美国－１株同源性较高（核苷酸与氨酸同源性分别大于９４．３％与８８．８％）,当为ⅠＢ亚型;上海株与意大利株的核昔酸同源性最高,为９８．１％。研究证明我国新疆、内蒙、西藏等地区抗ＨＤ阳性率比其他省市高并不是由于存在其他基因型所致。     

草鱼IGF—Ⅰ cDNA的克隆和在原核生物中的表达

根据亲缘关系较近的鲤鱼胰素样生长因子－Ⅰ（IGF－Ⅰ）cDNA设计一对引物,通过RT－PCR从草鱼（Ctenopharyngodon idellus）肝组织首次克隆了草鱼IGF－ⅠcDNA开放阅读框（ORF）片段,经序列分析表明克隆的草鱼IGF－ⅠcDNA为Ea－2亚型,ORF与鲤鱼有95％的同源性,与人有63％的同源性;草鱼IGF－Ⅰ蛋白与鲤鱼IGF－Ⅰ仅2个氨基酸残基不同,与人IGF－Ⅰ也仅有13个残基不同,将表达成熟草鱼IGF－Ⅰ(gcIGF-Ⅰ）蛋白的cDNA片段亚克隆至谷胱甘肽S－转移酶（GST）融合表达载体pGEX－4T－3,再将构建的重组表达载体pGEX-T-gcIGF-Ⅰ转入大肠杆菌BL21。在IPTG的诱导下,GST－gcIGF-Ⅰ融合蛋白高效表达。兔抗鲑鱼IGF－Ⅰ抗血清进行了Western Blot检测显示重组草鱼IGF－Ⅰ蛋白具有免疫活性。     

乙型肝炎病毒表面抗原aa126 Ile→Ser变异株HBsAg的暂时表达和抗原性鉴定

曾在一个儿童患者体内,发现一个新的乙型肝炎病毒（ＨＢＶ）变异株,其ＨＢｓＡｇ主蛋白ａａ１２６发生Ｉｌｅ（ＡＴＴ）到Ｓｅｒ（ＡＧＴ）的取代。已知ａｄｒ／ａｙｒ亚型ＨＢｓＡｇ１２６位为Ｉｌｅ,而ａｄｗ／ａｙｗ亚型ＨＢｓＡｇ１２６位为Ｔｈｒ,表明ＨＢｓＡｇ１２６Ｓｅｒ是一个新的变异株。用计算机做结构分析的结果表明,突变体ＨＢｓＡｇ１２６Ｓｅｒ主蛋白ａａ１２０－ａａ１３０区段的二级结构与野生型ａｄｒＨＢＶＨＢｓＡｇ１２６Ｉｌｅ相比发生明显的改变。这种构象的变化可能会影响ａ抗原决定簇（ａ１２４－ａａ１４７）的抗原性。为了证实这一点,构建了突变Ｓ基因表达质粒,在ＳＶ４０早期启动子的控制下进行抗原表达。利用ＨＢｓＡｇ９肽（Ｔｈｒ－Ｉｌｅ１２６－Ｐｒｏ－Ａｌａ－Ｇｌｎ－Ｇｌｙ－Ｔｈｒ－Ｓｅｒ－Ｍｅｔ）抗ｉ单克隆抗体和９肽（Ｔｈｒ－Ｔｈｒ１２６－Ｐｒｏ－Ａｌａ－Ｇｌｎ－Ｇｌｙ－Ｔｈｒ－Ｓｅｒ－Ｍｅｔ）抗ｔ单克隆抗体进行放射免疫测定,结果表明,这种Ｓｅｒ１２６突变蛋白对抗ｉ单克隆抗体的反应性比野生蛋白减弱,对抗ｔ单克隆抗体的反应性则与ＨＢｓＡｇ１２６Ｔｈｒ接近。但用三种抗－ａ单克隆抗体的检测结果揭示,突变蛋白ＨＢｓＡｇ１２６     

广西壮族自治区HIV—1流行毒株的基因序列测定和亚型分析

使用ＰＣＲ技术对１４份广西ＨＩＶ－１阳性感染者外周血单核细胞（ＰＢＭＣｓ）样品进行扩增,获得ＨＩＶ－１膜蛋白（ｅｎｖ）基因的核酸片段,并对其Ｃ２－Ｖ３及邻区３５０￣４５０个核苷酸序列进行了测定和分析。结果表明,１４份样品中９份为泰国Ｂ（Ｂ＇）亚型,５份为Ｅ亚型毒株。其中Ｂ＇亚型毒株的基因离散率为４．２％,与Ａ－Ｅ参考亚型及部分Ｂ亚型代表株序列相比较,与包括泰国、缅甸及云南德宏在内的Ｂ亚型毒株序列十     

Molecular phylogenetic analyses indicate a wide and ancient radiation of African hepatitis delta virus, suggesting a deltavirus genus of at least seven major clades

Hepatitis D virus (HDV) is a satellite of hepatitis B virus (HBV) for transmission and propagation and infects nearly 20 million people worldwide. The HDV genome is a compact circular single-stranded RNA genome with extensive intramolecular complementarity. Despite its different epidemiological and pathological patterns, the variability and geographical distribution of HDV are limited to three genotypes and two subtypes that have been characterized to date. Phylogenetic reconstructions based on the delta antigen gene and full-length genome sequence data show an extensive and probably ancient radiation of African lineages, suggesting that the genetic variability of HDV is much more complex than was previously thought, with evidence of additional clades. These results relate the geographic distribution of HDV more closely to the genetic variability of its helper HBV.     

丙型肝炎病毒多表位DNA疫苗的研究进展

丙型肝炎病毒（hepatitis C virus,HCV）是非甲非乙型肝炎的主要病原,目前还没有有效的预防和治疗手段。多表位DNA疫苗(multi-epitope DNA vaccine, minigenes/epigenes)是指通过筛选与组合优势抗原表位(包括T细胞、B细胞表位)基因,以能产生高效细胞、体液免疫应答进而清除HCV病毒为目的的新型核酸疫苗。其优势在于通过选择最具免疫保护潜力的表位以覆盖尽量多的病毒亚型和诱导全面的机体抗病毒免疫应答,并尽量减少无关、干扰和抑制序列可能产生的负面影响。本文介绍近年来国内外在丙型肝炎多表位DNA疫苗方面的研究进展,并展望了其发展方向。     

A replication enhancer of viral origin increases the mitotic stability of yeast transformants]

It is shown in this paper that a DNA fragment of Hepatitis B virus possessing structural features of yeast replication enhancer increases the mitotic stability of yeast transformants containing hybrid plasmids of episomal and replicative types. The mitotic stability of transformants with plasmid of the replicative type and with the replication enhancer increases only in [cir+] cells. Comparison of primary sequences of HBV DNA of different subtypes revealed that only DNA has unique structural features of the yeast enhancer of replication.     

Antigenic structure of hepatitis B surface antigen: identification of the "d" subtype determinant by chemical modification and use of monoclonal antibodies

Hepatitis B surface antigens (HBsAg) of both the adw and ayw subtypes were reductively methylated with formaldehyde in the presence of sodium cyanoborohydride. The effect on antigenicity was determined by radioimmunoassay with monoclonal antibodies specific for seven different antigenic determinants. The reaction was shown to eliminate specifically the "d" antigenic activity of HBsAg/adw and to have no effect on HBsAg/ayw. Moreover, the reaction had only a slight affect on HBsAg/adw at one of the "a" antigenic determinants. The sites of modification were determined and the extent of modification of each site was compared to the loss of "d" antigenic activity. These studies demonstrated that the loss of "d" activity was due to the modification of lysine 122 in HBsAg/adw, and that although the amino terminus and lysine residues 141 and 160 of both HBsAg/adw and HBsAg/ayw are reactive, their modification does not alter any measurable antigenic activity.     

Current Concepts of Viral Hepatitis and A Peek into the Future

New information has prompted revision of the conceptual framework for considering the epidemiology and virology of viral hepatitis. The means are now at hand to identify infections due to either Hepatitis A or B, as well as to implicate other etiologic agents in hepatitis. Immunologic evidence of variation in the antigens associated with Hepatitis B, and possibly in Hepatitis A, may explain some well known epidemiologic phenomena and has important implications in immune serum globulin prophylaxis. The ambiguous relationship of antigenemia and viremia in Hepatitis B is explored in relation to the hepatitis hazard of blood products, to trials of immune serum globulin, and to the potential role of the carrier-health worker in hepatitis transmission. The emerging concept of non-parenteral transmission of Hepatitis B is reviewed and future developments in the production of hepatitis vaccines and in experimental viral hepatitis in non-human primates is briefly discussed.     

HCV genotyping using statistical classification approach

The genotype of Hepatitis C Virus (HCV) strains is an important determinant of the severity and aggressiveness of liver infection as well as patient response to antiviral therapy. Fast and accurate determination of viral genotype could provide direction in the clinical management of patients with chronic HCV infections. Using publicly available HCV nucleotide sequences, we built a global Position Weight Matrix (PWM) for the HCV genome. Based on the PWM, a set of genotype specific nucleotide sequence "signatures" were selected from the 5' NCR, CORE, E1, and NS5B regions of the HCV genome. We evaluated the predictive power of these signatures for predicting the most common HCV genotypes and subtypes. We observed that nucleotide sequence signatures selected from NS5B and E1 regions generally demonstrated stronger discriminant power in differentiating major HCV genotypes and subtypes than that from 5' NCR and CORE regions. Two discriminant methods were used to build predictive models. Through 10 fold cross validation, over 99% prediction accuracy was achieved using both support vector machine (SVM) and random forest based classification methods in a dataset of 1134 sequences for NS5B and 947 sequences for E1. Prediction accuracy for each genotype is also reported.     

戊型肝炎病毒遗传多样性和进化机制的研究进展

戊型肝炎病毒(hepatitis E virus, HEV)是一种引发全球急性病毒性肝炎的人兽共患病病原。HEV具有丰富的遗传多样性,不同基因型或基因亚型的流行与地理位置、宿主物种以及防控策略等密切相关。欧洲和美洲HEV流行株为HEV-3,包括3a-i亚型,而亚洲流行株含HEV-3和HEV-4;我国的流行毒株已从HEV-1进化到HEV-4。近年来,研究发现HEV进化的影响机制,包括同义密码子使用模式、氨基酸突变和基因重组等,其中氨基酸突变是病毒持续流行的主要驱动力。因此,本文就HEV的分类、全球流行特征、进化机制等进行综述,以期为戊型肝炎的有效防控以及疫苗开发提供参考。     

A Mouse Model for Studying the Clearance of Hepatitis B Virus In Vivo Using a Luciferase Reporter

Hepatitis B virus(HBV) infection remains a global problem, despite the effectiveness of the Hepatitis B vaccine in preventing infection. The resolution of Hepatitis B virus infection has been believed to be attributable to virus-specific immunity. In vivo direct evaluation of anti-HBV immunity in the liver is currently not possible. We have developed a new assay system that detects HBV clearance in the liver after the hydrodynamic transfer of a reporter gene and over-length, linear HBV DNA into hepatocytes, followed by bioluminescence imaging of the reporter gene (Fluc). We employed bioluminescence detection of luciferase expression in HBV-infected hepatocytes to measure the Hepatitis B core antigen (HBcAg)-specific immune responses directed against these infected hepatocytes. Only HBcAg-immunized, but not mock-treated, animals decreased the amounts of luciferase expression, HBsAg and viral DNA from the liver at day 28 after hydrodynamic infection with over-length HBV DNA, indicating that control of luciferase expression correlates with viral clearance from infected hepatocytes.     

Preliminary biochemical characterization of two angiotensin II receptor subtypes

Two angiotensin II receptor subtypes (A and B) are described from rat and human tissues. They have been characterised using specific peptidic and non-peptidic ligands with affinities differing by 1000 fold or more. These subtypes are present in adrenal glomerulosa of both species. Human uterus contains only subtype A, whereas both subtypes are found in rat uterus. Vascular smooth muscle cells in culture express only subtype B. Dithio-threitol totally inhibits binding to subtype B, but enhances the affinity to subtype A. There is a good correlation between the affinities of the selected agonists and antagonists for the two subtypes in the various tissues tested which is a usual requirement for receptor classification.