HIV vaccine development using humanized mice

使用人源化小鼠开发艾滋病毒疫苗

• 批准号: 8129773
• 负责人: Robert Thomas Woodland
• 金额: $ 40.31万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-29 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8129773
• 关键词: Affinity; Antibodies; Antigens; B-Lymphocytes; Bacteria; Binding Sites; Blood; Carbohydrates; Cell Survival; Cell physiology; Cells; Characteristics; Chimera organism; Complex; Drug Formulations; Effectiveness; Elements; Epitopes; Failure; Goals; HIV; HIV Antibodies; HIV Antigens; HIV vaccine; HIV-1; Human; Human immunodeficiency virus test; Hybridomas; Immune; Immune Tolerance; Immune response; Immune system; Immunization; Immunoglobulin Somatic Hypermutation; Individual; Infection; Israel; Laboratories; Lymphocyte; Medical center; Methods; Modeling; Molecular; Mus; Polysaccharides; Process; Property; Proteins; Reaction; Relative (related person); Somatic Mutation; Source; Specificity; Structure of germinal center of lymph node; T-Lymphocyte; TI 2 Antigens; Testing; Time; Transfusion; Vaccination; Vaccines; Variant; Vertebral column; Virus; Virus Diseases; Virus-like particle; base; design; human monoclonal antibodies; immunogenicity; improved; in vitro activity; in vivo; mouse model; neutralizing antibody; novel strategies; reconstitution; research study; response; vaccine candidate; vaccine development

DESCRIPTION (provided by applicant): The best efforts of a legend of workers have failed to produce an HIV-1 vaccine that is capable of inducing broadly neutralizing antibody. Such antibodies exist and are protective as has been shown by passive transfer with the few monoclonal human antibodies available. While their fine specificity is different these monoclonals frequently demonstrated polyreactivity or self reactivity which may be a key feature of anti-HIV antibodies with broadly neutralizing potential. It has been hypothesized that the processes of immune tolerance normally anergizes or deletes such specificities explaining their absence following vaccination or infection. We have formulated an alternative hypothesis, namely that polyreactive B cells likely producing broadly neutralizing antibody can be either lost directly by somatic hypermutation and selection during the T cell dependent germinal center reaction induced by protein antigens characteristic of HIV vaccines or by failure to compete with more dominant high affinity anti-HIV clones also produced in germinal centers. To evaluate this hypothesis we propose to produce T cell dependent and independent versions of candidate HIV vaccines and test their efficacy at inducing broadly neutralizing anti-HIV antibodies. We will also examine distinct B cell subpopulations to determine their propensity to produce broadly neutralizing antibody and if they may be selectively activated by different molecular forms of HIV vaccine. We will use hybridomas to assess the range of anti-HIV antibodies induced early in the response to HIV vaccine and compare these specificities to ones that dominate in the post germinal center expressed antibody pool. These experiments will be done with human lymphocytes using a huPBL chimera model with markedly improved B cell survival and function recently developed in our laboratory. The goal of this study is to test the hypothesis that an HIV vaccine made by conjugating HIV antigens onto a complex carbohydrate backbone or in the form of a virus like particle has the potential to induce broadly reactive neutralizing anti-HIV antibodies that will inactivate the virus and/or keep it from infecting healthy susceptible cells. The efficacy of this new class of HIV vaccine is derived from its ability to induce responses not altered by somatic mutation and to directly activate subpopulations of protective B cells not normally stimulated by the current HIV vaccine formulations. These protective B cells are evolutionarily adapted to produce rapid responses to both viruses and bacteria and the antibodies they produce following their stimulation frequently show a broad (polyreactive) specificity. It is noteworthy that laboratory selected anti-HIV antibodies with broad neutralizing activity that can protect a host from infection when given in a transfusion show a similar polyreactive character. To determine the effectiveness of this new class of vaccine relative to the current form of vaccine we will immunize humanized mice, which are mice that lack their own immune system that have been reconstituted with human blood lymphocytes. These mice respond to vaccination much like humans would, in that, they make human antibodies for HIV, which can be tested for neutralizing activity in vitro, and the immunized mice can be challenged with infectious virus to demonstrate the in vivo efficacy of the vaccine candidate. Because a number of mice can be reconstituted using blood from a single donor we have the opportunity to compare immune responses to different vaccine formulations in what is immunologically an individual subject thereby eliminating inter-donor response variation. These studies provide a new approach for the design and testing of HIV vaccines.

描述（由申请人提供）：传奇工作者的最大努力未能生产出能够诱导广泛中和抗体的 HIV-1 疫苗。此类抗体存在并且具有保护性，正如通过少数可用的单克隆人类抗体的被动转移所显示的那样。虽然它们的精细特异性不同，但这些单克隆抗体经常表现出多反应性或自身反应性，这可能是具有广泛中和潜力的抗 HIV 抗体的关键特征。据推测，免疫耐受过程通常会激活或消除此类特异性，从而解释了疫苗接种或感染后它们的缺失。我们提出了另一种假设，即可能产生广泛中和抗体的多反应性 B 细胞可能会因 HIV 疫苗特有的蛋白质抗原诱导的 T 细胞依赖性生发中心反应期间的体细胞超突变和选择而直接丢失，或者因无法与也在生发中心产生的更具优势的高亲和力抗 HIV 克隆竞争而直接丢失。为了评估这一假设，我们建议生产 T 细胞依赖性和独立版本的候选 HIV 疫苗，并测试它们诱导广泛中和抗 HIV 抗体的功效。我们还将检查不同的 B 细胞亚群，以确定它们产生广泛中和抗体的倾向，以及它们是否可以被不同分子形式的 HIV 疫苗选择性激活。我们将使用杂交瘤来评估在 HIV 疫苗反应早期诱导的抗 HIV 抗体的范围，并将这些特异性与在生发中心后表达的抗体库中占主导地位的抗体进行比较。这些实验将使用人类淋巴细胞进行，使用我们实验室最近开发的 huPBL 嵌合体模型，该模型显着改善了 B 细胞的存活和功能。这项研究的目的是检验以下假设：通过将 HIV 抗原缀合到复杂的碳水化合物主链上或以病毒样颗粒的形式制成的 HIV 疫苗有可能诱导广泛反应性的中和性抗 HIV 抗体，从而灭活病毒和/或防止其感染健康的易感细胞。这种新型 HIV 疫苗的功效源自其诱导不因体细胞突变而改变的反应的能力，以及直接激活当前 HIV 疫苗配方通常不会刺激的保护性 B 细胞亚群的能力。这些保护性 B 细胞在进化上适应了对病毒和细菌产生快速反应，并且它们在受到刺激后产生的抗体经常表现出广泛的（多反应性）特异性。值得注意的是，实验室选择的具有广泛中和活性的抗 HIV 抗体在输血时可以保护宿主免受感染，也显示出类似的多反应特征。为了确定这类新型疫苗相对于现有疫苗形式的有效性，我们将对人源化小鼠进行免疫，这些小鼠缺乏自身的免疫系统，但已用人血淋巴细胞重建。这些小鼠对疫苗接种的反应与人类非常相似，因为它们产生人类 HIV 抗体，可以在体外测试其中和活性，并且可以用传染性病毒攻击免疫小鼠，以证明候选疫苗的体内功效。由于可以使用来自单个供体的血液来重建许多小鼠，因此我们有机会在免疫学上比较个体受试者对不同疫苗制剂的免疫反应，从而消除供体间反应的差异。这些研究为艾滋病毒疫苗的设计和测试提供了新方法。