RNA-based gene therapy for the treatment and prevention of HIV: from bench to bedside

Gene therapy is considered a feasible approach for the treatment and prevention of HIV/AIDS. Targeting both viral genes and host dependency factors can interfere with the viral lifecycle and prevent viral replication. A number of approaches have been taken to target these genes, including ribozymes, aptamers, and RNAi based therapies. A number of these therapies are now beginning to make their way into clinical trials and providing proof of principle that gene therapy is a safe and realistic option for treating HIV. Here, we focus on those therapies that have progressed along the pipeline to preclinical and clinical testing.     

艾滋病治疗药物-HIV抑制剂作用机制及研究进展

艾滋病（AIDS）是由人类免疫缺陷病毒（HIV）感染而引起的慢性进行性致死性传染病,又称获得性免疫缺陷综合症,目前无有效治愈的方法,严重危害着人类的健康。现今,艾滋病治疗药物主要包括逆转录酶抑制剂、蛋白酶抑制剂、进入抑制剂、整合酶抑制剂四大类化学药物和一些中草药制剂。抗HIV药物虽然不能完全治愈艾滋病,但可以控制艾滋病病情的发展,延长患者的无病生存期,提高患者的生活质量。本文就艾滋病发病机制、HIV抑制药物的抗病机制、副作用及其研究进展做一综述。     

Effects of signal peptide exchange on HIV-1 glycoprotein expression and viral infectivity in mammalian cells

In certain cell systems, exchange of the human immunodeficiency virus (HIV) Env signal peptide (SP) sequence with that of heterologous SPs has been shown to increase gp120 transport and secretion. Here we demonstrate that exchange of the HIV-Env-SP with those from erythropoietin or tissue plasminogen activator in the proviral context does not increase wild-type membrane-bound Env expression or incorporation into released virions. In fact, virion infectivity was decreased. These infectivity decreases were largely due to effects on Env transport and/or function and only to a minor extent to cis effects as a result of the sequence exchanges themselves. Thus, in fact, it is not advantageous to employ heterologous SPs to achieve high-level expression of functional cell surface membrane- or virion-associated HIV-Env.     

艾滋病治疗药物--HIV 抑制剂作用机制及研究进展

艾滋病(AIDS)是由人类免疫缺陷病毒(HIV)感染而引起的慢性进行性致死性传染病,又称获得性免疫缺陷综合症,目前无有效治愈的方法,严重危害着人类的健康。现今,艾滋病治疗药物主要包括逆转录酶抑制剂、蛋白酶抑制剂、进入抑制剂、整合酶抑制剂四大类化学药物和一些中草药制剂。抗HIV药物虽然不能完全治愈艾滋病,但可以控制艾滋病病情的发展,延长患者的无病生存期,提高患者的生活质量。本文就艾滋病发病机制、HIV抑制药物的抗病机制、副作用及其研究进展做一综述。     

HIV-1 remission and possible cure in a woman after haplo-cord blood transplant

1. Download : Download high-res image (247KB)
2. Download : Download full-size image

     

治疗艾滋病的构想——多重复合型抗体

由于HIV的高度变异性．人们现在仍未成功研制出有效的疫苗或抗体。通过在体内已经存在的聚合型抗体(如IgM、IgA)的启示,可以联想合成一种含有不同亚单位的复合型抗体——多重复合型抗体,通过这个复合型抗体的多效特异性去消灭各种HIV,从而达到通过被动体液免疫来消除细胞外的HIV的目的。再通过同抑制病毒在细胞内反转录及疫苗免疫疗法,从根本上消灭HIV,最后治愈艾滋病。     

HIV的发现者——蒙塔格尼尔

对蒙塔格尼尔的生平和学术贡献进行了简略的介绍。蒙塔格尼尔是20世纪最伟大的病毒学家之一，他发明了病毒的体外培养方法，深入研究了病毒的致癌机制，发现了干扰素，特别是在1983年鉴定了艾滋病的病原HIV从而使人们对这种传染病的发生原因有了深入性的理解。蒙塔格尼尔对生命科学发展的贡献使他成为近几年诺贝尔奖的热门人物之一。     

44例HIV感染者的临床分析

目的探讨HIV感染者在皮肤科的病种分布、临床表现特点、传播途径。方法回顾分析44例住院、门诊HIV感染者皮肤疾病的种类、特征及实验室指标。结果HIV感染者皮肤黏膜病变的有25例（56．81％）,以感染性疾病病毒、梅毒感染为主,分别为12例（27．27％）、6例（13．63％）,疾病种类依次为梅毒、尖锐湿疣、生殖器疱疹病毒、带状疱疹、支原体、衣原体、淋病、全身湿疹和口腔念珠菌等9种。有2种以上皮肤黏膜疾病者8例（18．18％）。感染途径以男性同性恋为主17例,其次是异性恋13例。结论HIV感染者在皮肤科就诊时皮肤黏膜损害以病毒和梅毒感染为主。     

疫苗的研究

疫苗为人类预防传染病作出了巨大的贡献。介绍了各种疫苗的作用方式和制备方法,并对目前的研究热点作一简要概述。     

HIV整合位点的生物信息学分析

已有研究证明,HIV整合位点的选择,与宿主基因组功能和染色体结构特性之间存在着紧密的联系,但是具体的选择机制还不明确。使用聚类分析、特征提取、分类分析等生物信息学方法,对HIV整合位点序列进行分析和研究,挖掘HIV整合位点序列之间的关系,探索HIV整合位点的选择规律。通过实验和计算,从HIV整合位点集合中提取出了含有6个特征向量的向量集,该向量集与大部分整合位点的特征向量具有较高的相关性,从而提示了HIV整合位点选择中的规律性,即符合向量集的宿主DNA序列可为HIV的整合位点。研究结果为进一步揭示HIV整合位点的选择机制提供了可供参考的依据。     

熊猴存在TRIM5/TRIMCyp杂合子基因型

缺乏合适的动物模犁是制约艾滋病研究取得重大突破的关键瓶颈之一.细胞内的抗病毒蛋白被称为限制因子.研究不同灵长类动物抗HIV-1宿主限制因子的存在形式及作用机制对建立合适AIDS灵长类动物模型有十分重要的意义.TRIM5α是哺乳动物细胞中一种重要和关键的限制因子,它以物种依赖的方式限制包括HIV-1在内的逆转录病毒的感染.TRIM5-CypA融合基因是存在于新大陆猴与旧大陆猴中的一种独特的TRIM5基因形式.为了研究不同灵长类动物TRIM5基因的存在方式,该文对熊猴、藏婀猴、红面猴及中闰恒河猴4个物种共110只灵长类动物进行了TRIM5-CypA融合模式的研究.首次发现熊猴也存在TRIM5-CypA基因融合现象.熊猴TRIMCyp融合基因形成模式类似于北平顺猴TRIMCyp融合基因模式,即CypA假基因的cDNA序列通过逆转座方式插入到TRIM5基凶的3'-UTR区域.基因序列分析表明,该基因与北平顶猴相应基因序列高度相似;并且其TRIM5内含子6的3'-剪接位点也相应存存G-to-T突变现象(G/T).这提示熊猴也极有可能像北平顶猴一样表达TRIM5-CypA融合蛋白,从而导致熊猴可能跟北平顶猴一样可能被HIV-1感染.因此,熊猴极有希望成为一种新的HIV/AIDS灵长类动物模型.     

Modeling Maternal-Infant HIV Transmission in the Presence of Breastfeeding with an Imperfect Test

An important public health question is to determine the probabilities of perinatal HIV transmission and when it occurs, whether antepartum, intrapartum, or postpartum through breastfeeding. However, this is a difficult problem because the presence of HIV infection in an infant can only be ascertained through viral assays in the postpartum period. We propose a model that simultaneously estimates the risks of antepartum, intrapartum, and postpartum transmissions together with the sensitivity of the screening tests for HIV infection. The model allows estimating of infectivity through breast milk during postpartum periods. The methods are illustrated on a South African randomized clinical trial of extended AZT versus a short course of nevirapine in infants whose mothers had no access to antenatal antiretroviral therapy.     

HIV-1中和抗体疫苗研究进展

由于HIV具有与其它微生物极为不同的生物学特点,HIV疫苗的研究面临着前所未有的困难和挑战。20多年来,艾滋病疫苗研究主要采用了诱发中和抗体为主或细胞免疫为主两种策略,然而至今尚无实质性突破。诱发有效中和抗体一直是传统疫苗研发的重要策略,但HIV的高变异、多亚型等特点,使该策略在HIV疫苗研发中的应用成效甚微。近年来,一些具有广谱中和活性的HIV单抗的发现及其相应抗原表位的阐明,给HIV中和抗体疫苗的研究带来了新的希望。综合分析与评述这些进展,对于重新思考艾滋病疫苗和采用更好的策略进行艾滋病疫苗研究会衣纸帮助。     

HIV介导的细胞凋亡

细胞凋亡是多细胞生物的一种生理性细胞死亡 ,它和坏死性细胞死亡是两种不同的细胞死亡形式 ,细胞凋亡是细胞内在的有规律的机制引起的 ,它可由细胞内部因素和外部刺激所诱导 ,细胞凋亡有其固有的形态特点 ,这种“自杀”行动对机体的正常发育和新陈代谢都是必要的 ,有助于维持组织稳态 ,对于机体是有利的。如细胞凋亡异常将会给机体带来各种病理后果。另外由于细胞凋亡的可诱导性 ,就为疾病的治疗提供了一条新思路。近年来发现 ,ＨＩＶ病毒也参与了细胞凋亡的诱导和抑制 ,在这些过程中相关的病毒基因的表达和相应蛋白质的合成起着关键性的作…     

CD32+CD4+ T Cells Are Highly Enriched for HIV DNA and Can Support Transcriptional Latency

1. Download : Download high-res image (230KB)
2. Download : Download full-size image

     

Repetitive exposures with simian/human immunodeficiency viruses: strategy to study HIV pre-clinical interventions in non-human primates

BACKGROUND: Non-human primate models for human immunodeficiency virus (HIV) infection represent a valuable pre-clinical tool to evaluate interventions (e.g., topical microbicides, vaccines, and chemoprophylaxis) designed to prevent transmission or slow disease progression after infection. Standard transmission models use a single-dose exposure with high, non-physiologic levels of virus to approach 100% infection rates of control animals. These single-exposure models do not represent the circumstances of mucosal HIV transmission in humans and may result in misleading data with regard to intervention efficacy. Therefore, we have developed a repetitive mucosal exposure model using doses of virus that better reflects human exposures. METHODS: The virus used for these evaluations was simian-human immunodeficiency virus [SHIVSF162P3 (R5-using, subtype B HIV-1 envelope)] and the virus dose used (approximately 10(5)-10(6) viral particle equivalents or approximately 10 tissue culture infectious doses per exposure) approximates viral loads observed in the semen during acute HIV-1 infection. Using the repeated mucosal exposure approach, we have evaluated a candidate vaginal microbicide (cellulose acetate phthalate, CAP) given 15 minutes prior to each weekly virus exposure. Pig-tailed macaques were exposed weekly by vaginal inoculations with and without microbicide until systemic viral RNA was detected. RESULTS: Groups of na?ve control monkeys were infected after an average of three to four exposures for the vaginal route of inoculation. Data from the first application of this monkey model to evaluate the topical microbicide CAP suggested that protection from SHIV infection was possible with three of four CAP-treated monkeys remaining uninfected after 12 exposures (P = 0.015). CAP efficacy was markedly improved from 66% in a previous single-dose virus exposure study to 92% in this repeated exposure system. CONCLUSIONS: Our experience with using repetitive virus exposures to study topical microbicides and the findings to date from this study provides a basis to refine monkey models to more closely resemble human exposure during HIV transmission. This model may be highly relevant to pre-clinical evaluation for a variety of therapeutic interventions which is discussed here.     

DC-SIGN蛋白在家蚕系统中的表达及生物活性研究

目的：构建人DC-SIGN基因片段的家蚕表达系统,进行目的产物表达、鉴定及生物活性分析。方法：从体外刺激分化的DC细胞中克隆出DC-SIGN cDNA,在家蚕表达载体pBacPAK8的BamHⅠ和EcoRⅠ位点构建成重组质粒pBacPAK8-DC-SIGN,与线性化的Bm-BacPAK6病毒基因组DNA共转染家蚕细胞,空斑筛选得到重组病毒Bm-BacPAK-DC-SIGN,重组病毒感染家蚕细胞BmN,Western blot检测表达产物;HIV-1包膜糖蛋白gp120与表达产物孵育检测其生物活性。结果：构建了稳定表达人DC-SIGN蛋白片段的家蚕杆状病毒表达系统;成功表达了DC-SIGN蛋白片段,且能特异性地与HIV-1包膜糖蛋白gp120结合。结论：成功地在家蚕杆状病毒表达系统中表达了人DC-SIGN蛋白片段,具有天然DC-SIGN蛋白样的生物活性,为其抗体制备及AIDS防治药物的研发奠定了基础。