Immunogenicity of the newly identified V3 crown vulnerable site

新发现的 V3 冠脆弱位点的免疫原性

基本信息

批准号：
10548294
负责人：
XIANGPENG KONG
金额：
$ 27.06万
依托单位：
NEW YORK UNIVERSITY SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-07-05 至 2024-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10548294
关键词：
Animals Antibodies Antibody Response Antigens Area B-Lymphocytes Binding Biological Assay Blood specimen Categories Characteristics Cryoelectron Microscopy Dental crowns Enzyme-Linked Immunosorbent Assay Epitope Mapping Epitopes Foundations Future Genes Glycoproteins Goals HIV HIV Envelope Protein gp120 HIV vaccine HIV-1 Human Immunization Immunoglobulin A Immunoglobulin Class Switching Immunoglobulin G Location Maps Membrane Proteins Modeling Modification Molecular Target Monoclonal Antibodies Mus N-terminal Negative Staining Oryctolagus cuniculus Outcome Patients Polysaccharides Regimen Site Structure Surface Testing V3 Loop Vaccines Virus beta pleated sheet design disulfide bond immunogenic immunogenicity neutralizing antibody nonhuman primate novel pathogen purge rational design response scaffold screening vaccination strategy virus envelope

项目摘要

To be able to induce antibody (Ab) responses against the HIV-1 envelope (Env) spike vulnerable sites defined by broadly neutralizing antibodies (bnAbs) will likely lead to a protective vaccine. Many HIV bnAbs have been discovered and their epitopes have been carefully mapped on the surface of Env, and these epitopes have been categorized into a number of well characterized classes. However, a consistently induction of bnAb responses targeting any of those currently well characterized vulnerable sites is still extremely difficult because of the unusual features of these bnAbs and their associated vulnerable sites, such as the requirement of a long CDR H3 to penetrate the glycan shield of the Env spike. Thus, identification of additional vulnerable sites with more favorable characteristics for rational targeting may help to increase our capability of induction of bnAb responses. We have identified recently a new vulnerable site by mapping the epitope of bnAb M4008_N1 and characterizing its antibody-antigen interaction. M4008_N1 is a bnAb that can neutralize about 40% of the primary isolates tested and its lineage class-switched to both IgG and IgA. We showed that by cryo-EM the epitope of M4008_N1 is centered at the crown region of the third variable loop (V3) of gp120 in the prefusion Env trimer. The unique characteristics of the M4008_N1 epitope and its mode of interaction with the V3 crown suggest a strategy to induce M4008_N1-like Ab responses by a V3 priming and heterologous boosting with stabilized Env trimer. As we have demonstrated previously, the V3 crown Ab responses are relatively straightforward to elicit by V3 immunogens. We therefore hypothesize that, since the V3 crown -hairpin is a common structure and M4008_N1 can bind V3 loop itself, antibodies that engage the N-terminal strand by a β- sheet interaction, like that of M4008_N1, can be induced by V3 immunogens, and such M4008_N1-like antibody responses can then be boosted with a subsequent immunization with a V3-stabilized Env trimer, which harbors the whole epitope of bnAb M4008_N1. Early versions of the SOSIP immunogens were known to induce non-neutralizing V3 antibodies, but some V3-stabilized versions seemed to be able to purge non- neutralizing V3 antibody responses. These V3-stabilized SOSIP trimers can therefore be used for the heterologous boost to induce M4008_N1-like antibody responses. We will test our hypothesis in a rabbit model using a set of carefully selected to be optimal in the heterologous prime/boost strategy, and we have two Aims. (1) Selection of the best immunogen combination, (2): Rabbit immunization and characterization of the antibody responses. The expected outcome of this project is a proof of principle demonstration for the immunogenicity targeting the newly identified V3 crown vulnerable site and to lay a foundation for future extensive immunogenicity studies including potentially non-human primate studies.

能够诱导针对HIV-1信封（ENV）尖峰脆弱位点的抗体反应（AB）反应通过广泛中和抗体（BNAB）可能会导致受保护的疫苗。许多艾滋病毒bnab是发现及其表位已在Env的表面仔细映射，这些表位具有被分类为许多表征良好的类。但是，BNAB的一致诱导针对目前易受伤害地点的任何人的响应仍然非常困难，因为这些bnabs及其相关脆弱站点的异常特征，例如长期要求 CDR H3穿透Env Spike的聚糖盾牌。那，标识了其他脆弱网站合理靶向的更有利的特征可能有助于提高我们的BNAB诱导能力回答。我们最近通过映射BNAB M4008_N1和表征其抗体 - 抗原相互作用。 M4008_N1是一种可以中和约40％的BNAB 测试的主要分离株及其谱系类别切换到IgG和IgA。我们证明了Cryo-Em的 M4008_N1的发作以GP120的第三变量循环（V3）的冠状区域为中心 env trimer。 M4008_N1发作的独特特征及其与V3冠的互动方式提出一种通过V3启动和异源增强的策略来诱导M4008_N1样AB响应稳定的env触发器。正如我们之前所证明的，V3皇冠AB反应相对直接引起V3免疫原子。因此，我们假设，因为V3冠发蛋白是一个共同的结构和M4008_N1可以结合V3环本身，抗体，通过β-与N末端链接合像M4008_N1一样，纸互动可以由V3免疫原和类似于M4008_n1 然后，可以使用随后的免疫来增强抗体反应，并使用V3稳定的ENV夹子，它包含BNAB M4008_N1的整个剧集。已知SOSIP免疫原子的早期版本诱导非中和V3抗体，但一些V3稳定版本似乎能够清除非 - 中和V3抗体反应。因此，这些V3稳定的SOSIP三聚机可用于异源增强诱导M4008_N1样抗体反应。我们将在兔模型中检验我们的假设使用一组精心列出的选择在异源/增强策略中是最佳的，我们有两个目标。（1）选择最佳免疫原组合，（2）：兔免疫抑制和表征抗体反应。该项目的预期结果是针对原则证明的证明针对新确定的V3皇冠脆弱部位的免疫原性，并为未来奠定基础广泛的免疫原性研究，包括潜在的非人类灵长类动物研究。