HIV感染与硒衰竭

近年来硒在艾滋病发生发展中的作用越来越引起人们的关注,ＨＩＶ感染者及ＡＩＤＳ病人具有渐进性硒衰竭的症状,而病毒及Ｔ细胞有可能具有编码硒蛋白的功能,其中一种病毒编码的硒蛋白可能对ＨＩＶ的表达起抑制作用。在体外,硒对ＨＩＶ １的复制具有调节作用,为硒的临床应用提供了潜在的前景。     

ZAP融合蛋白抑制HIV病毒模型的构建及功能分析

ZAP是一种抗病毒因子,能够特异性结合病毒RNA并招募细胞中的RNA酶降解所结合的靶RNA,从而抑制某些病毒的复制,如鼠白血病病毒(MLV)、辛德比斯病毒(SIN).ZAP对HIV病毒抑制作用并不明显.Tat和Rev是HIV编码的两种可以特异性结合HIVRNA的蛋白质,将它们与ZAP构建成融合蛋白,使得融合蛋白通过Tat或Rev结合HIVRNA并通过ZAP降解HIVRNA,从而抑制HIV假病毒载体携带基因的表达.这一结果为抑制HIV病毒提供了一个新思路,也支持了ZAP招募mRNA降解机器降解靶RNA的模型.     

反式激活应答元件RNA在HIV-1感染中的作用

反式激活应答(transactivation response,TAR)元件RNA作为HIV-1中的一种非编码RNA,从转录与翻译水平负调控HIV-1的基因表达.同时HIV-1采取了相应的策略拮抗TAR RNA的负调控作用:病毒蛋白Tat或细胞蛋白TAR RNA结合蛋白(TRBP)结合TAR RNA后,分别在转录与翻译水平促进HIV-1的基因表达.此外,TAR编码的miRNA有助于保持HIV的潜伏感染及阻止细胞凋亡.TAR与其它蛋白间相互作用及其功能的研究对于深入了解HIV-1感染细胞后的调控机制,寻求新的抗HIV治疗靶点具有重要意义.     

一种新型细胞源性AIDS病疫苗正待试验

美国马里兰州巴尔的摩人类病毒研究所所长 Robert Gallo今年 5月公布了他们将在近两年内在巴尔的摩和乌干达两地试验新型艾滋病疫苗的计划 .这种疫苗是由人类病毒所疫苗组主任 George Lewis及其同事David Hone研制的 .与其它抗 HIV疫苗不同 ,新型疫苗可口服 ,并采用沙门氏菌作为 HIV基因的载体 .当非致病的沙门氏菌携带 HIV gag蛋白及其他病毒蛋白片段编码基因 (这些基因最初曾被牛津大学的 An-drew Me Michael制作裸 DNA疫苗 )进入人体细胞后 ,缺陷型沙门氏菌的细胞壁破裂并释放病毒 DNA,宿主细胞将其转录、翻译为 HIV蛋白 ,从…     

EIAV与HIV分子生物学相关性研究进展

马传染性贫血病毒 (equineinfectiousanemiavirus,EIAV)与人类免疫缺陷病毒(humanimmunodeficiencyvirus ,HIV)同属逆转录病毒科、慢病毒属成员。两者在形态结构、抗原特性、基因组构成以及病毒与宿主的持续作用等方面极为相似 ,且EIAV具有独特的快速发病进程和明显的病程分界 ,使其成为研究HIV的基因变异与临床症状之间相互关系的理想动物模型。EIAV疫苗是我国拥有自立知识产权的世界上唯一的慢病毒疫苗 ,以该疫苗为基础 ,开发新型HIV疫苗将成为今后的发展策略。近年国内外学者对EIAV及HIV的分子生物学进行了深入研究 ,确定了与病毒毒力相关的某些基因及编码蛋白 ,并在疫苗的研究上取得了一定进展。     

HIV-1辅助蛋白Vif的结构与功能

HIV-1 Vif(viral infectivity factor)蛋白是由保守的vif基因编码的碱性蛋白质,是HIV-1病毒的辅助调节蛋白之一.研究表明Vif蛋白具有调节病毒侵入、组装、出芽和成熟等功能.此外,Vif蛋白能够特异性地与体内抗病毒因子APOBEC3G相互作用,增强病毒的感染性.因此,针对HIV-1Vif蛋白进行抑制剂设计已经成为抗HIV药物研究的热点之一.本文对HIV-1Vif蛋白的结构与功能研究的最新进展进行了综述.     

硬粒小麦基因组中疑似硒蛋白生物信息分析

目的：用生物信息学的方法对硬粒小麦基因组中疑似硒蛋白的氨基酸序列进行综合分析,进一步找寻其为硒蛋白的生物信息依据,并初步分析推断其功能。方法：利用Vector NTI等多种生物信息学工具对硬粒小麦AYl46587．1序列中发现的疑似硒蛋白编码序列进行综合分析研究。结果：发现2段目标编码序列具有与某些蛋白酶相似的生物信息学特征,并推测其蛋白编码具有目前未知的机理。结论：推断AYl46587．1序列中存在编码未知硒蛋白的编码段,其编码的硒蛋白参与硬粒小麦胚芽生长发育时期能量调节。     

TSG101基因研究进展

人TSG101基因是近年来发现的一个新的抑瘤基因候选,定位于11p15.1-15.2,其编码产物TSG101蛋白N端区与泛素连接催化区同源。近年来的研究表明,TSG101基因与多种肿瘤密切相关,其产物TSG101蛋白具有多种重要功能,由于其参与HIV病毒的感染过程,使得研制和开发针对HIV病毒的基因药物来治疗艾滋病成为可能。     

HIV感染导致MT4细胞蛋白表达差异的初步研究

为了比较MT4细胞株感染HIV-1的ⅢB株前后的蛋白质表达差异,我们分别提取MT4细胞及感染了人类免疫缺陷病毒(HIV)的MT4细胞的总蛋白质,通过双向电泳分离,使用Image Master 2D Elite 3.10图像分析软件分析获得的凝胶图谱,寻找差异点,使用质谱仪鉴定获得的差异点蛋白质.结果表明感染HIV和未感染HIV的MT4细胞有40个蛋白质点差异,HIV感染后减少的蛋白质点有12个,增多的有28个,通过质谱分析,29个蛋白质得到鉴定.其中HIV感染后下调的蛋白质有能量代谢相关蛋白、肌动蛋白相关蛋白及假想蛋白等;上调的蛋白有肌动蛋白、酶类蛋白、免疫蛋白及假想蛋白等.通过研究我们可以看出宿主细胞感染HIV病毒后有多个蛋白发生变化,可能和HIV与宿主细胞的相互作用有关.为了研究HIV感染的机制必须去除高丰度蛋白,针对特定功能的蛋白质进行具体研究.     

核酶与AIDS治疗

 艾滋病(AIDS)是由人免疫缺陷病毒(HIV)感染并破坏人体免疫功能所导致的一种综合症. 作为具有核酸内切酶活性的RNA小分子,核酶能特异性结合及切割HIV病毒靶分子,并促进靶分子mRNA的裂解,且能相继与多个靶分子RNA作用,同时又不影响宿主细胞RNA. 利用核酶治疗艾滋病不仅没有化疗药物常见的副作用,而且由于核酶本身具有RNA剪切酶活性,可同时剪切HIV mRNA和HIV生命过程中重要的调节蛋白mRNA.因此,较其它基因疗法如RNAi、DNA decoy等,更能有效地抑制HIV复制,并且对由HIV变异而导致的耐药病毒株同样有效,同时对病毒突变的诱导作用也较其它抗病毒药物低.因此,在抗AIDS基因治疗研究中具有潜在的应用价值. 本文在对核酶的结构、催化作用机制及其对HIV-1的作用机制进行概述的基础上,重点讨论了近年来核酶作用于HIV的研究进展以及对AIDS治疗的应用前景.     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.