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Knock-in mice expressing germline-reverted broadly neutralizing HIV antibodies

表达种系恢复的广泛中和艾滋病毒抗体的敲入小鼠

基本信息

批准号：
10641828
负责人：
DAVID NEMAZEE
金额：
$ 63.53万
依托单位：
SCRIPPS RESEARCH INSTITUTE, THE
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-07-05 至 2024-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10641828
关键词：
Acceleration Address Affinity Animal Experiments Animal Model Antibodies Antibody Binding Sites Antibody Formation Antigens B-Lymphocytes Binding Binding Sites Cell Count Cell Line Cells Chronic Clinical Trials Data Dose Engineering Epitopes Funding Gene Mutation Gene Targeting Genes Genetic Goals HIV HIV Antibodies HIV vaccine Human Immune response Immunization Immunoglobulin Class Switching In Vitro Individual Infection Infection Control Knock-in Knock-in Mouse Knowledge Memory B-Lymphocyte Modeling Monkeys Mus Mutate Mutation Pathway interactions Patients Pattern Peptides Peripheral Blood Mononuclear Cell Physiological Plasma Cells Polysaccharides Predictive Value Primates Site Somatic Mutation Sorting Specificity Speed Study models Testing Vaccination Vaccine Design Vaccine Research Vaccines Variant Virus competitive environment cost design efficacy evaluation env Glycoproteins global health human model improved in vivo insertion/deletion mutation insight mouse model neutralizing antibody novel vaccines optimism response simian human immunodeficiency virus tool vaccination strategy vaccine candidate vaccine strategy vaccine trial

项目摘要

This is a renewal R01 application to exploit knock-in mouse models and hypermutating human B cell lines carrying germline-reverted broadly neutralizing antibodies (gl-bNAbs) against HIV Env with the goal to speed HIV vaccine research. Developing an HIV vaccine is a major global health objective as no effective vaccine yet exists. bnAbs to HIV Env glycoprotein can likely control infection but eliciting bnAbs by vaccination is challenging because of Env genetic variability and the fact that responses to conserved Env epitopes are weak. bnAbs are made naturally in some patients, but usually only after years of infection, when they provide no real protection. However, many individual bnAbs can provide passive protection in animal models, suggesting that elicitation of these antibodies could be protective, particularly if bnAbs to several conserved sites can be raised simultaneously. To begin to investigate the best ways to elicit bnAbs by vaccination, we have previously generated B cell lines and knock-in mice carrying inferred gl-bnAbs for VRC01, PGT121, b12, 4E10 and other specificities. gl-bnAb mouse models are valuable for antigen design and vaccination studies because they carry B cells with the potential to become bnAbs after appropriate stimulation and somatic mutation. Placement of the V(D)J genes into the physiological Ig loci allows the knock-in B cells to undergo normal H-chain class switching and V-region hypermutation. Moreover, knock-in mice allow vaccination studies in a convenient, relatively low-cost mouse model. One can seed B cells from these mice at physiologically low numbers in otherwise WT mice and assess their responses in the face of competition from non bnAb clones. In these cell lines and mice, we have been carrying out studies to evaluate whether the imputed gl-bnAbs develop normally and to assess various vaccine candidates and immunization strategies. We have tested so-called germline-targeting immunogens engineered to bind better to gl-bnAbs than immunogens derived from WT Env. In the present proposal we focus on two aspects of vaccine design: the use of validated, rather than inferred, gl-bnAb precursors and an assessment of the ease of selectability of beneficial mutations using somatically-mutating human gl-bnAb cell lines and gl-bnAb mice. We hypothesize that by taking these approaches we will identify preferred gl-bnAbs that most effectively mature to become bnAbs and preferred immunogens or selection paths that should most effectively promote bnAb production when tested in primates. Because the problem of poor precursor affinity to antigen and uncertain paths to affinity maturation by somatic mutation are limitations to all immune responses, knowledge obtained here should be applicable to a variety of vaccine targets.

这是一个更新的 R01 应用程序，用于开发敲入小鼠模型和超突变人类 B 细胞系携带针对 HIV Env 的种系恢复广泛中和抗体 (gl-bNAb)，目的是加速 HIV疫苗研究。由于没有有效的疫苗，开发艾滋病毒疫苗是全球主要健康目标但仍然存在。 HIV 包膜糖蛋白的 bnAbs 可能可以控制感染，但通过疫苗接种来引发 bnAbs 是不可能的由于 Env 遗传变异性以及对保守 Env 表位的反应是具有挑战性的虚弱的。 bnAb 是在某些患者体内自然产生的，但通常只有在感染多年后，当它们提供没有真正的保护。然而，许多单独的 bnAb 可以在动物模型中提供被动保护，表明这些抗体的引发可能具有保护作用，特别是如果 bnAbs 是针对几个保守的站点可以同时提高。为了开始研究通过疫苗接种产生 bnAb 的最佳方法，我们之前已经生成了携带 VRC01、PGT121 的推断 gl-bnAb 的 B 细胞系和敲入小鼠， b12、4E10 和其他特性。 gl-bnAb 小鼠模型对于抗原设计和疫苗接种很有价值研究是因为它们携带的 B 细胞在适当的刺激后有可能成为 bnAb 体细胞突变。将 V(D)J 基因置于生理 Ig 基因座中，使得敲入 B 细胞能够经历正常的 H 链类别转换和 V 区超突变。此外，敲入小鼠允许在方便、成本相对较低的小鼠模型中进行疫苗接种研究。人们可以从这些小鼠身上接种 B 细胞 WT 小鼠的生理数量较低，并评估它们面对竞争时的反应来自非 bnAb 克隆。在这些细胞系和小鼠中，我们一直在进行研究以评估是否推算的 gl-bnAb 正常发育并评估各种候选疫苗和免疫接种策略。我们已经测试了所谓的种系靶向免疫原，这些免疫原经过改造可以更好地与 gl-bnAb 结合比源自 WT Env 的免疫原。在本提案中，我们重点关注疫苗设计的两个方面：使用经过验证的而不是推断的 gl-bnAb 前体以及对选择难易程度的评估使用体细胞突变的人类 gl-bnAb 细胞系和 gl-bnAb 小鼠进行有益突变。我们假设通过采取这些方法，我们将确定最有效成熟的首选 gl-bnAb 成为 bnAb 和最有效促进 bnAb 的首选免疫原或选择路径在灵长类动物身上进行测试时产生的结果。由于前体与抗原亲和力差且不确定的问题通过体细胞突变实现亲和力成熟的途径是所有免疫反应的限制，所获得的知识这里应该适用于多种疫苗靶点。