全球结核病疫苗研究进展

本文旨在对全球结核病疫苗研究进展进行系统综述,描述国际上目前进入临床试验不同阶段的新型疫苗,包括重组卡介苗、亚单位疫苗、治疗性疫苗等,分析我国结核病疫苗研究现状,介绍国际研究发展趋势,如人类疫苗计划、全细胞疫苗、多阶段疫苗等,并对存在的问题和挑战进行讨论,展望未来发展趋势。     

轮状病毒VP4亚单位疫苗研究进展

轮状病毒是全球范围内导致5岁以下婴幼儿严重腹泻的主要病原体,造成了巨大的经济负担和社会负担。疫苗预防接种是控制轮状病毒感染最为有效的手段,但在轮状病毒导致的死亡率较高的非洲和亚洲部分低收入国家,目前已经上市的轮状病毒疫苗的有效性较低,且会增加肠套叠的风险。更加安全、有效的轮状病毒疫苗对于降低轮状病毒感染导致的发病率和死亡率具有重要意义。目前,各国科研人员试图从多个方面提高轮状病毒疫苗的有效性,非复制型基因工程亚单位疫苗是目前轮状病毒疫苗研究的主要方向。文中就目前轮状病毒亚单位疫苗,特别是基于VP4蛋白的亚单位疫苗的研究进展进行了综述,以期对轮状病毒疫苗的发展提供借鉴意义。     

Progress in Brucella vaccine development

Brucella spp. are zoonotic, facultative intracellular pathogens, which cause animal and human disease. Animal disease results in abortion of fetuses; in humans, it manifests flu-like symptoms with an undulant fever, with osteoarthritis as a common complication of infection. Antibiotic regimens for human brucellosis patients may last several months and are not always completely effective. While there are no vaccines for humans, several licensed live Brucella vaccines are available for use in livestock. The performance of these animal vaccines is dependent upon the host species, dose, and route of immunization. Newly engineered live vaccines, lacking well-defined virulence factors, retain low residual virulence, are highly protective, and may someday replace currently used animal vaccines. These also have possible human applications. Moreover, due to their enhanced safety and efficacy in animal models, subunit vaccines for brucellosis show great promise for their application in livestock and humans. This review summarizes the progress of brucellosis vaccine development and presents an overview of candidate vaccines.     

Tuberculosis vaccine design: influence of the completed genome sequence

Tuberculosis continues to be a major health problem, with more adults dying from Mycobacterium tuberculosis than any other pathogen world-wide.With the onset of the HIV epidemic and an increase in drug-resistant M. tuberculosis strains, the need for an improved vaccine has become an international priority.The recent completion of the genome sequences for two M. tuberculosis strains provides a wealth of information that can be used to design new strategies for vaccine development. The challenge comes in making rational choices from among the 4,000 genes of the most probable candidate immunogens or virulence genes.Thus, a well-designed screen is needed to reduce the number of candidates that must be tested. Presently, the most valuable role that bioinformatics can play is to provide such a screen.     

Immune responses of mice to influenza subunit vaccine in combination with CIA07 as an adjuvant

CIA07 is an immunostimulatory agent composed of E. coli DNA fragments and modified LPS lacking the lipid A moiety. In this study, we investigated whether CIA07 promotes immune responses as an adjuvant to the influenza subunit vaccine. Balb/c mice were immunized intramuscularly once or twice at a 4-week interval with the trivalent influenza subunit vaccine antigen alone or in combination with CIA07 as adjuvant. Antigen-specific serum antibody titers and hemagglutination-inhibition (HI) antibody titers were assessed. At 4 weeks after each immunization, the antigen-specific total serum IgG antibody titer in mice receiving CIA07 was 2 to 3 times higher than that in animals administered antigen alone (P<0.05). The CIA07-treated group additionally displayed higher HI antibody titers against each of the 3 vaccine strains, compared to the antigen group. Animals receiving antigen alone displayed barely detectable antigen-specific serum IgG2a antibody titers. In contrast, coadministration of CIA07 with antigen led to significantly enhanced IgG2a antibody responses, suggesting that CIA07 stimulates a Th1-type immune response. Moreover, the CIA07-treated group displayed a marked increase in the number of interferon gamma-producing CD8(+) T cells in splenocytes. These data collectively demonstrate that CIA07 has the ability to induce both Th1-type cellular and Th2-type humoral immune responses to the influenza subunit vaccine, and support its potential as an effective adjuvant to the influenza vaccine.     

黏膜免疫佐剂研究进展

黏膜免疫可以保护黏膜表面防止病毒入侵,也是对外周免疫病理性紊乱的一种有效的免疫处理方式。有效的黏膜免疫应答通常依赖于合适的佐剂,以引发机体从先天性免疫向适应性免疫过渡。目前,有3种细胞产物具有作为黏膜免疫佐剂的潜力,它们是ADP-核糖基化的肠毒素(霍乱毒素和大肠杆菌不耐热肠毒素)、人工合成的非甲基化的CpG二核苷酸序列,以及单磷酰基类脂A。本文综述了不同黏膜免疫佐剂的可能作用机制及其功能,概述了近期应用研究的进展。     

The development and use of vaccine adjuvants

Interest in vaccine adjuvants is intense and growing, because many of the new subunit vaccine candidates lack sufficient immunogenicity to be clinically useful. In this review, I have emphasized modern vaccine adjuvants injected parenterally, or administered orally, intranasally, or transcutaneously with licensed or experimental vaccines in humans. Every adjuvant has a complex and often multi-factorial immunological mechanism, usually poorly understood in vivo. Many determinants of adjuvanticity exist, and each adjuvanted vaccine is unique. Adjuvant safety is critical and can enhance, retard, or stop development of an adjuvanted vaccine. The choice of an adjuvant often depends upon expensive experimental trial and error, upon cost, and upon commercial availability. Extensive regulatory and administrative support is required to conduct clinical trials of adjuvanted vaccines. Finally, comparative adjuvant trials where one antigen is formulated with different adjuvants and administered by a common protocol to animals and humans can accelerate vaccine development.     

Toward novel vaccines against tuberculosis: current hopes and obstacles

Approximately 2 million people die of tuberculosis (TB) each year. The current vaccine, Bacille Calmette-Guérin (BCG), albeit widely employed, does not protect against adult pulmonary disease, and new vaccines are urgently needed to reduce the incidence of TB worldwide. New insights into the cellular and molecular mechanisms that underlie the interactions between Mycobacterium tuberculosis and its host have been exploited to develop novel vaccine candidates that recently have entered clinical trials. This review provides a brief overview of different approaches toward a new vaccination strategy and summarizes major challenges for the next decade.     

Advances in antibody-mediated immunity against Mycobacterium tuberculosis: implications for a novel vaccine strategy

Cell-mediated immunity is considered to be the major component of the host response against Mycobacterium tuberculosis, whereas antibody-mediated immunity historically has been considered inconsequential. In recent years, studies from several groups have challenged the traditional dogma and demonstrated that monoclonal antibodies can modify various aspects of mycobacterial infections. This review describes the experimental evidence supporting a role for antibodies in defense against mycobacterial infections and outlines future challenges to the field of antibody-mediated immunity against M. tuberculosis, with particular emphasis on the implications of these findings for a novel vaccine strategy.     

Accelerating vaccine development and deployment: report of a Royal Society satellite meeting

The Royal Society convened a meeting on the 17th and 18th November 2010 to review the current ways in which vaccines are developed and deployed, and to make recommendations as to how each of these processes might be accelerated. The meeting brought together academics, industry representatives, research sponsors, regulators, government advisors and representatives of international public health agencies from a broad geographical background. Discussions were held under Chatham House rules. High-throughput screening of new vaccine antigens and candidates was seen as a driving force for vaccine discovery. Multi-stakeholder, small-scale manufacturing facilities capable of rapid production of clinical grade vaccines are currently too few and need to be expanded. In both the human and veterinary areas, there is a need for tiered regulatory standards, differentially tailored for experimental and commercial vaccines, to allow accelerated vaccine efficacy testing. Improved cross-fertilization of knowledge between industry and academia, and between human and veterinary vaccine developers, could lead to more rapid application of promising approaches and technologies to new product development. Identification of best-practices and development of checklists for product development plans and implementation programmes were seen as low-cost opportunities to shorten the timeline for vaccine progression from the laboratory bench to the people who need it.     

Study on immunity of dengue virus and dengue vaccine development

In the study of vaccines for dengue viruses, which are multivalent immunization, genetically and antigenically distinct, we should have more sophisticated understanding of viral immune physiology. Because the immune response to dengue and its role in the pathophysiology of dengue fever and dengue hemorrhagic fever are multifaceted, several different efforts have been made to engineer a protective vaccine. Because of space limitations, this review is focused only on vaccines that have emerged from preclinical studies into clinical trial.     

Study on immunity of dengue virus and dengue vaccine development

In the study of vaccines for dengue viruses,which are multivalent immunization,genetically and antigenically distinct,we should have more sophisticated understanding of viral immune physiology.Because the immune response to dengue and its role in the pathophysiology of dengue fever and dengue hemorrhagic fever are multifaceted,several different efforts have been made to engineer a protective vaccine.Because of space limitations,this review is focused only on vaccines that have emerged from preclinical studies into clinical trial.     

Structural view of the regulatory subunit of aspartate kinase from Mycobacterium tuberculosis

The aspartate kinase (AK) from Mycobacterium tuberculosis (Mtb) catalyzes the biosynthesis of aspartate family amino acids, including lysine, threonine, isoleucine and methionine. We determined the crystal structures of the regulatory subunit of aspartate kinase from Mtb alone (referred to as MtbAKβ) and in complex with threonine (referred to as MtbAKβ-Thr) at resolutions of 2.6 ? and 2.0 ?, respectively. MtbAKβ is composed of two perpendicular non-equivalent ACT domains [aspartate kinase, chorismate mutase, and TyrA (prephenate dehydrogenase)] per monomer. Each ACT domain contains two α helices and four antiparallel β strands. The structure of MtbAKβ shares high similarity with the regulatory subunit of the aspartate kinase from Corynebacterium glutamicum (referred to as CgAKβ), suggesting similar regulatory mechanisms. Biochemical assays in our study showed that MtbAK is inhibited by threonine. Based on crystal structure analysis, we discuss the regulatory mechanism of MtbAK.     

Expression of Helicobacter pylori TonB protein in transgenic Arabidopsis thaliana: toward production of vaccine antigens in plants

Background: The aim of this study was to produce a recombinant version of the highly antigenic Helicobacter pylori TonB (iron‐dependent siderophore transporter protein HP1341) in transgenic plants as a candidate oral vaccine antigen. Materials and Methods: Using Agrobacterium‐mediated gene transfer, we introduced three different constructs of the tonB gene into the genome of the model plant Arabidopsis thaliana. We investigated transgene insertion by PCR, produced TonB antibodies for analysis of the production of the recombinant protein in plants, verified the identity of the protein produced by mass spectrometry analysis, and analyzed the number of genetic inserts in the plants by Southern blotting. Results: Three different constructs of the expression cassette (full‐length tonB, tonB truncated in the 5′ end removing the codons for a transmembrane helix, and the latter construct with codons for the endoplasmic reticulum SEKDEL retention signal added to the 3′ end) were used to find the most effective way to express the TonB antigen. Production of TonB protein was detected in plants transformed with each of the constructs, confirmed by both Western blotting and mass spectrometry analysis. No considerable differences in protein expression from the three different constructs were observed. The protein concentration in the plants was at least 0.05% of the total soluble proteins. Conclusions: The Helicobacter pylori TonB protein can be produced in Arabidopsis thaliana plants in a form that is recognizable by rabbit anti‐TonB antiserum. These TonB‐expressing plants are highly suitable for animal studies of oral adminstration as a route for immunization against Helicobacter infections.     

Comparative evaluation of intranasal and subcutaneous route of immunization for development of mucosal vaccine against experimental tuberculosis

Activation of mucosal immunity in the respiratory tract is crucial for protection against respiratory infections. Whether the intranasal route of vaccination imparts better protection against pulmonary tuberculosis than that of subcutaneous vaccination remains a debatable issue. In this study, we have investigated the effect of the routes of immunization on the induction of immunoprotection against experimental tuberculosis employing mycobacterial culture filtrate proteins complexed with dimethyldioctadecylammonium bromide. Vaccination via intranasal and subcutaneous routes triggered immune activation in the spleen and cervical lymph node, while the former route of vaccination lead to higher antigen-specific lymphocyte proliferation, interferon-gamma, interleukin-12 and interleukin-4 responses in cervical lymph node and induction of antigen-specific IgA responses at mucosal level of the respiratory tract. Mice vaccinated via the intranasal route were found to be better protected against experimental tuberculosis particularly in lung compared to subcutaneous-immunized mice. These results emphasize the importance of the intranasal route vaccination in tuberculosis.     

结核分枝杆菌蛋白亚单位疫苗与疫苗诱导的T细胞免疫记忆研究进展

牛分枝杆菌减毒活疫苗--卡介苗(bacillus Calmette-Guérin,BCG)对预防严重的儿童结核病有效,但其免疫保护效率随儿童年龄增长而降低。BCG不能提供终身免疫保护可能与其诱导的记忆性T细胞主要是寿命较短的效应记忆性T细胞有关。新型结核分枝杆菌蛋白亚单位疫苗将有效的抗原有机组合起来,在适宜的疫苗佐剂辅助下诱导Th1型免疫应答。动物实验表明,增加抗原谱可有效提高亚单位疫苗的保护效率。更重要的是,亚单位疫苗在体内持续时间较短,可诱导寿命较长的中央记忆性T细胞,提供比BCG更持久的免疫保护力。记忆性T细胞的分化受抗原特性与剂量、细胞因子、转录因子及雷帕霉素等的调控。对亚单位疫苗及其诱导的免疫记忆进行研究将对新型结核分枝杆菌疫苗的设计与评价产生积极影响。     

针对潜伏结核感染的 A39 DNA 疫苗构建及其免疫原性研究

选取结核分枝杆菌潜伏相关抗原Rv2029c、结核分枝杆菌优秀抗原Ag85A和Rv3425,构建针对潜伏感染的结核分枝杆菌DNA疫苗pVAX1／Ag85A-Rv3425-Rv2029c （A39）,并对其免疫原性进行研究。首先用聚合酶链反应（PCR）扩增Ag85A基因,构建重组质粒pVAX1／Ag85A （A）;PCR扩增 Ag85A-Rv3425连接片段,插入pVAX1载体,构建重组质粒pVAX1／Ag85A-Rv3425（A3）;PCR扩增Rv2029c基因,插入A3,构建重组质粒pVAX1／Ag85A-Rv3425-Rv2029c （A39）。将构建成功的重组质粒转入 HEK293T细胞,蛋白免疫印迹法验证质粒在真核细胞中得到表达。在大肠埃希菌BL21中成功表达和纯化去除信号肽的Ag85A、Rv3425和Rv2029c蛋白。用质粒免疫C57BL／6小鼠,共分为5组：PBS、pVAX1、A、A3和A39组,采用电脉冲导入免疫,每2周免疫1次,共3次,用酶联免疫斑点检测（ELISPOT）、酶联免疫吸附试验（ELISA）、流式细胞术等方法检测细胞免疫和体液免疫水平。结果显示,A39免疫小鼠后,能引发强烈的细胞免疫反应﹝γ干扰素（IFN-γ）、肿瘤坏死因子α（TNF-α）和白细胞介素2（IL-2）高水平分泌﹞,外周血CD4＋／CD8＋ T细胞比值增加,CD8＋穿孔素＋ T细胞比例增加。结果表明,构建的A39 DNA疫苗能引发强烈的免疫反应,显示出良好的抗结核潜力,可作为结核分枝杆菌新型候选疫苗。     

新型兽用疫苗的研究进展

新型兽用疫苗是免疫学和病毒学的研究热点,主要包括亚单位疫苗、基因工程缺失苗、重组病毒活载体疫苗和基因疫苗。上前已经被广泛的应用于研究和疫病的防治上。最近的疫苗发展方向集中于在基因疫苗上。高效、安全、稳定、成本低是疫苗开发的重点。本文介绍了新型疫苗的现状,以及今后发展的趋势和策略。     

结核病免疫机制及疫苗研究进展

结核病是一种棘手的重大传染病.虽然存在一些有一定疗效的治疗药物,亦有预防性疫苗--卡介苗(BCG);但结核病仍在世界范围流行,且发病率和病死率居高不下.结核病的免疫病理机制及疫苗研究近年来取得了一定的进展.结核分枝杆菌通过Toll样受体(TLR)等模式识别受体,激活巨噬细胞的天然免疫反应,清除细菌和调节获得性免疫反应....