科学家开发出实验性猿类艾滋病病毒疫苗

美国研究人员开发出一种实验性猿类免疫缺陷病毒疫苗,可大幅降低恒河猴感染猿类艾滋病病毒的风险。这一研究成果为开发人类艾滋病疫苗提供了新思路。研究显示,与注射安慰剂疫苗的恒河猴相比,注射实验性疫苗的恒河猴感染猿类免疫缺陷病毒(SIV)的风险低80%。反复接触病毒后,大部分注射疫苗的恒河猴最终感染猿类免疫缺陷病毒,即猿类艾滋病病毒,但血液中病毒     

HIV/艾滋病疫苗:策略及展望

全球范围内艾滋病的流行使发展安全有效的疫苗势在必行。本文讨论了各种不同类型的艾滋病疫苗的优点和缺点,包括传统疫苗(灭活疫苗、减毒活疫苗)和新型疫苗(病毒颗粒样疫苗、重组亚单位疫苗、重组活载体病毒疫苗),同时也指出了发展艾滋病疫苗所面临的挑战,如病毒的变异、没有充足的动物模型和HIV感染免疫系统本身。概述了正在进行的艾滋病疫苗的临床试验,并对下一步研究进行了展望。     

SHIV减毒株在AIDS疫苗研究中的应用

艾滋病,即获得性免疫缺陷综合症(Acquired Immunodeficiency Syndrome, AIDS)是由人免疫缺陷病毒(Human Immunodeficiency Virus, HIV)引起的,以全身免疫系统严重损害为特征的传染性疾病.感染者终身携带病毒,迄今仍缺乏有效的预防和治愈措施.艾滋病已成为威胁人类健康的最大传染性疾病之一.历史上对付传染性疾病最经济有效的方法就是发展安全有效的疫苗.     

谁发现了艾滋病病毒？

艾滋病曾经是人们谈之色变的疾病,然而今天尽管人类还不能征服艾滋病,但对它已经有了比较充分的了解。人类认识艾滋病,是和发现艾滋病病毒,即人免疫缺陷病毒(HIV),分不开的。不过,在是谁第一个发现 HIV 这个问题上,科学界有过一场一波三折的争夺战。两个"独立发现"1981年6月5日,美国亚特兰大疾病控制中心的周刊上发表了一则报道,说洛杉矶的两     

美研究人员发现2种艾滋病病毒抗体

美国科研人员不久前发现了2种艾滋病病毒抗体。这2种抗体能抑制艾滋病病毒在人体内的活动。这一发现有助于推动艾滋病疫苗和药物的研发。     

人类免疫缺陷病毒疫苗的研究进展

人类免疫缺陷病毒疫苗是控制艾滋病的最佳方法,动物模型证实该病毒疫苗是可行的。人类免疫缺陷病毒中和抗体可达到足够高的水平以预防该病毒感染,但有型特异性,人类免疫缺陷病毒特异性细胞毒T淋巴细胞不能单独预防该病毒感染,但能将病毒血病控制在低水平,目前,人们研究重点集中于病毒特异性抗性体和T细胞反应。现有疫苗尚不能诱导对原发性病毒株具有广泛中和能力的抗体。然而,重组痘病毒疫苗和DNA疫苗提示细胞毒T淋巴细胞反应对来自不同进化分支的原发病毒株有广泛的交叉反应力,人们需找到新的免疫原来诱导中和抗体,以取得最佳细胞毒T淋巴细胞反应。     

人类免疫缺陷病毒黏膜疫苗

在以往的20年间,有关发展艾滋病疫苗的研究曾经进行了大量的工作,但进展不大,通常诱生基于抗包膜抗体的疫苗效果并不理想。目前一般认为,细胞免疫应答,特别是CD8细胞毒性T淋巴细胞(CTL)／抑制细胞和CD4辅助性T淋巴细胞在人类免疫缺陷病毒的控制上是必需的。因此能诱生细胞免疫应答的疫苗在控制人类免疫缺陷病毒的播散上至关重要。本文阐述了有关黏膜疫苗的理论、艾滋病黏膜疫苗的种类以及经口免疫耐受性问题,并提出艾滋病应当视为一种自身免疫病。故抗炎症或免疫抑制药物应用似有其可取之处。     

科学家发现新艾滋病病毒抗体或有助于疫苗的研发

澳大利亚墨尔本大学宣布,该校研究人员在一些艾滋病病毒携带者身上识别出1种艾滋病病毒抗体,有望在此基础上研发出预防艾滋病的疫苗。研究人员在分析100名艾滋病病毒携带者血液样本时发现,这些人感染艾滋病病毒后,体内能够产生1种抗体,这种抗体可促使人体免疫系统找到并攻击艾滋病病毒,     

一种新型HIV疫苗能有效预防SHIV通过黏膜感染

HIV严峻的流行形势迫切需要艾滋病疫苗,特别是黏膜疫苗。法国科学家Morgane Bomsel发表在最新一期Immunity中的文章表明,由该实验室研制的HIV黏膜疫苗能有效预防免疫缺陷病毒的黏膜感染。该疫苗是由包裹gp41亚单位抗原的病毒小体组成。该疫苗肌肉注射和滴鼻两种方式免疫恒河猴,     

ALVAC和AIDSVAX艾滋病联合疫苗研究进展

艾滋病流行形势日益严峻已成为严重的公共卫生问题,安全有效的疫苗是防治艾滋病最为有效的手段。2009年底,美国和泰国研究人员共同宣布基于有过失败"前科"的两种疫苗(ALVAC和AIDSVAX)的联合使用可以将人体感染艾滋病病毒的风险降低31.2%,这是人类首次获得具有一定免疫保护效果的艾滋病疫苗。本文就两种疫苗单独和联合免疫的临床试验进行综述。     

The Progress on the Studies of HIV/AIDS Vaccine

人类控制HIV感染长远的目标是发展安全、有效、廉价的HIV AIDS疫苗。但经 2 0多年的努力 ,人类探索HIV AIDS疫苗之路仍在继续。分析了疫苗研究的复杂性和发展HIV AIDS疫苗过程中所面临的挑战 ,并对发展HIV AIDS疫苗的可能性从实验和临床方面进行了阐述。同时结合HIV感染的免疫应答原理对现有的各种HIV AIDS疫苗研究策略作一综述 ,并根据以往HIV AIDS疫苗研究的经验和教训提出未来疫苗的发展思路及展望。     

AIDS猕猴模型在HIV疫苗研究中的应用

对HIV疫苗的研究一直是国际上艾滋病方面研究的热点和难点。动物模型则为疫苗研究必不可缺少的重要工具,缺乏合适的动物模型很大程度上制约了AIDS疫苗的研究。目前在国际上SIV或SHIV感染的猕猴模型为最常用的AIDS研究模型,受猕猴背景及病毒特性等多种因素的影响,使得以上两种模型在HIV疫苗研究中仍存在一定的局限性。为了更好地发挥猕猴模型在HIV疫苗研究中的巨大潜力,开发理想的AIDS猕猴模型已成为目前HIV疫苗研究的首要任务。本文简要介绍了AIDS疫苗的研发策略、研发概况以及SIV/SHIV猕猴模型在HIV疫苗中的应用,并对其中存在的问题及其应用前景进行了探讨。     

猕猴模型在HIV疫苗研究中的应用

对HIV疫苗的研究一直是国际上艾滋病方面研究的热点和难点。动物模型则为疫苗研究必不可缺少的重要工具,缺乏合适的动物模型很大程度上制约了AIDS疫苗的研究。目前在国际上SIV或SHIV感染的猕猴模型为最常用的AIDS研究模型,受猕猴背景及病毒特性等多种因素的影响,使得以上两种模型在HIV疫苗研究中仍存在一定的局限性。为了更好地发挥猕猴模型在HIV疫苗研究中的巨大潜力,开发理想的AIDS猕猴模型已成为目前HIV疫苗研究的首要任务。本文简要介绍了AIDS疫苗的研发策略、研发概况以及SIV/SHIV猕猴模型在HIV疫苗中的应用,并对其中存在的问题及其应用前景进行了探讨。     

Immunogenicity of a DNA prime and recombinant adenovirus boost regime significantly varies between rhesus macaques of Chinese and Indian origins

BACKGROUND: Due to an ever increasing shortage of rhesus macaques of Indian origin (InR) that have been generally used for preclinical AIDS vaccine trials in non-human primates, demand is rising for Chinese rhesus macaques (ChR). However, the immunogenicity of an AIDS vaccine candidate has not been compared in parallel in both rhesus macaque subspecies. METHODS: ChR and InR were immunized with SIV/HIV DNA and adenovirus vaccine and their immune responses to SIV and HIV evaluated. RESULTS: SIV Gag- and Env-specific T-cell responses and SIV-specific lymphoproliferative responses measured in ChR were significantly weaker than those in InR (P < 0.05). By contrast, antibody responses to SIV Env, Tat, and Nef in ChR were stronger than those in InR (P < 0.05). CONCLUSIONS: Immunogenicity of an AIDS vaccine can vary significantly depending on the geographic origin implying genetic differences of macaques. This must be considered when describing and interpreting results of such vaccine studies.     

Dominant induction of vaccine antigen-specific cytotoxic T lymphocyte responses after simian immunodeficiency virus challenge

Cytotoxic T lymphocyte (CTL) responses are crucial for the control of human and simian immunodeficiency virus (HIV and SIV) replication. A promising AIDS vaccine strategy is to induce CTL memory resulting in more effective CTL responses post-viral exposure compared to those in natural HIV infections. We previously developed a CTL-inducing vaccine and showed SIV control in some vaccinated rhesus macaques. These vaccine-based SIV controllers elicited vaccine antigen-specific CTL responses dominantly in the acute phase post-challenge. Here, we examined CTL responses post-challenge in those vaccinated animals that failed to control SIV replication. Unvaccinated rhesus macaques possessing the major histocompatibility complex class I haplotype 90-088-Ij dominantly elicited SIV non-Gag antigen-specific CTL responses after SIV challenge, while those induced with Gag-specific CTL memory by prophylactic vaccination failed to control SIV replication with dominant Gag-specific CTL responses in the acute phase, indicating dominant induction of vaccine antigen-specific CTL responses post-challenge even in non-controllers. Further analysis suggested that prophylactic vaccination results in dominant induction of vaccine antigen-specific CTL responses post-viral exposure but delays SIV non-vaccine antigen-specific CTL responses. These results imply a significant influence of prophylactic vaccination on CTL immunodominance post-viral exposure, providing insights into antigen design in development of a CTL-inducing AIDS vaccine.     

Worldwide survey of AIDS vaccine challenge studies in nonhuman primates: vaccines associated with active and passive immune protection from live virus challenge.

An AIDS Vaccine Surveillance System (AVSS) was designed and implemented to track the rapidly growing international database supporting the development of promising AIDS vaccines. Both preclinical nonhuman primate (NHP) and clinical human trials are tracked by the AVSS. This report presents summary data generated from the AVSS on the NHP AIDS vaccine/live virus challenge studies only. Summary data on more than 100 preclinical HIV/SIV vaccines are presented within the framework of 1) 13 arbitrary Vaccine Types, 2) studies grouped by animal model (i.e., chimpanzee/HIV-1, and macaque/SIV, HIV-2), and 3) immunization approach (i.e., active and passive). Systematic and timely presentations of these summary data, both here and in future reports, aim to promote a clearer understanding of both earlier and more recent preclinical AIDS vaccine developments.     

The chemical bases of the various AIDS epidemics: Recreational drugs,anti-viral chemotherapy and malnutrition

In 1981 a new epidemic of about two-dozen heterogeneous diseases began to strike non-randomly growing numbers of male homosexuals and mostly male intravenous drug users in the US and Europe. Assuming immunodeficiency as the common denominator the US Centers for Disease Control (CDC) termed the epidemic, AIDS, for acquired immunodeficiency syndrome. From 1981-1984 leading researchers including those from the CDC proposed that recreational drug use was the cause of AIDS, because of exact correlations and of drug-specific diseases. However, in 1984 US government researchers proposed that a virus, now termed human immunodeficiency virus (HIV), is the cause of the non-random epidemics of the US and Europe but also of a new, sexually random epidemic in Africa. The virus-AIDS hypothesis was instantly accepted, but it is burdened with numerous paradoxes, none of which could be resolved by 2003: Why is there no HIV in most AIDS patients, only antibodies against it? Why would HIV take 10 years from infection to AIDS? Why is AIDS not self-limiting via antiviral immunity? Why is there no vaccine against AIDS? Why is AIDS in the US and Europe not random like other viral epidemics? Why did AIDS not rise and then decline exponentially owing to antiviral immunity like all other viral epidemics? Why is AIDS not contagious? Why would only HIV carriers get AIDS who use either recreational or anti-HIV drugs or are subject to malnutrition? Why is the mortality of HIV-antibody-positives treated with anti-HIV drugs 7–9%, but that of all (mostly untreated) HIV-positives globally is only 1–4%? Here we propose that AIDS is a collection of chemical epidemics, caused by recreational drugs, anti-HIV drugs, and malnutrition. According to this hypothesis AIDS is not contagious, not immunogenic, not treatable by vaccines or antiviral drugs, and HIV is just a passenger virus. The hypothesis explains why AIDS epidemics strike non-randomly if caused by drugs and randomly if caused by malnutrition, why they manifest in drug- and malnutrition-specific diseases, and why they are not self-limiting via anti-viral immunity. The hypothesis predicts AIDS prevention by adequate nutrition and abstaining from drugs, and even cures by treating AIDS diseases with proven medications.     

Mathematical Study of a Staged-Progression HIV Model with Imperfect Vaccine

A staged-progression HIV model is formulated and used to investigate the potential impact of an imperfect vaccine. The vaccine is assumed to have several desirable characteristics such as protecting against infection, causing bypass of the primary infection stage, and offering a disease-altering therapeutic effect (so that the vaccine induces reversal from the full blown AIDS stage to the asymptomatic stage). The model, which incorporates HIV transmission by individuals in the AIDS stage, is rigorously analyzed to gain insight into its qualitative features. Using a comparison theorem, the model with mass action incidence is shown to have a globally-asymptotically stable disease-free equilibrium whenever a certain threshold, known as the vaccination reproduction number, is less than unity. Furthermore, the model with mass action incidence has a unique endemic equilibrium whenever this threshold exceeds unity. Using the Li-Muldowney techniques for a reduced version of the mass action model, this endemic equilibrium is shown to be globally-asymptotically stable, under certain parameter restrictions. The epidemiological implications of these results are that an imperfect vaccine can eliminate HIV in a given community if it can reduce the reproduction number to a value less than unity, but the disease will persist otherwise. Furthermore, a future HIV vaccine that induces the bypass of primary infection amongst vaccinated individuals (who become infected) would decrease HIV prevalence, whereas a vaccine with therapeutic effect could have a positive or negative effect at the community level.     

Strategy for AIDS Prevention and Treatment

HIV/AIDS has been circulating in China for over 25 year. While making progress and achievements on HIV/AIDS prevention,there still are great challenge and difficulties such as HIV epidemic controlling and vaccine research.     

树突状细胞在AIDS灵长类动物模型疾病进程中的作用

非人灵长类动物模型在艾滋病(AIDS)发病机制、传播途径、疫苗和药物等方面的研究中具有重要作用。树突状细胞(DC)作为最重要连接先天免疫与获得性免疫的抗原递呈细胞,在AIDS发病进程中扮演着重要的角色。研究非人灵长类AIDS动物模型中DC亚群数量、表型以及功能的变化,对揭示AIDS发病机制具有十分重要的意义。该文将重点总结近些年来DC亚群在AIDS动物模型发病机制中的作用研究进展,为以后的研究提供思路。