Synthetic HIV Vaccine Targeting Glycopeptide Neutralization Epitopes

靶向糖肽中和表位的合成 HIV 疫苗

基本信息

批准号：
9506651
负责人：
LAI-XI WANG
金额：
$ 45.59万
依托单位：
UNIV OF MARYLAND, COLLEGE PARK
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-07-11 至 2021-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9506651
关键词：
AIDS/HIV problem Alkynes Antibodies Antibody Affinity Antibody Response Antigens Azides Bacteriophages Binding Biochemical Biological Assay Complex Copper Crystallization Epidemic Epitopes Germ Lines Glycopeptides Goals HIV HIV Envelope Protein gp120 HIV vaccine HIV-1 HIV-1 vaccine Health Heterogeneity Human Immune Sera Immune response Immunization Immunize Immunology Individual Knowledge Light Maps Methods Mutation Oryctolagus cuniculus Pattern Peptides Periodicity Polysaccharides Reaction Receptors, Antigen, B-Cell Recombinants Research Role Series Site Specificity Speed Structure Synthetic Vaccines Testing Vaccines Viral Virus-like particle base combat cycloaddition density design experimental study glycosylation immunogenicity improved insight mannosyl(5)-N-acetyl(2)-glucose mannosyl(9)-N-acetylglucosamine2 neutralizing antibody novel public health relevance reconstitution scaffold social vaccine development

项目摘要

DESCRIPTION (provided by applicant): An effective HIV vaccine capable of inducing broadly neutralizing antibodies remains a significant goal in combating the HIV/AIDS epidemic. Recent discovery of a new class of glycan-reactive broadly neutralizing antibodies (bNAbs), represented by PG9, PG16, PGT121, and PGT128, has shed light on design of novel epitope-based vaccine. These bNAbs neutralize primary HIV-1 strains with remarkable breadth and potency and appear to target glycopeptide epitopes located in the variable domains (V1/V2 or V3) of HIV-1 gp120. Mutational, biochemical and structural studies suggest that the epitopes of PG9 and PG16 are glycopeptides consist of two N-glycans (at the N160 and N156/N173 glycosylation sites) and a patch of peptide in the V1/V2 domain, while the epitopes of PGT128 appear to involve the N-glycans at the N332 and N301 sites. However, further characterization of the glycan specificity was complicated by the heterogeneity in glycosylation of gp120. We used a synthetic approach to constructing homogeneous V1V2 and V3 glycopeptides carrying defined glycans for further defining the glycan specificity, which led to the identification of a cyclic glycopeptide epitope carrying a Man5GlcNAc2 glycan at N160 and a sialylated N-glycan at N156/N173 site as the minimal epitopes for PG9/PG16. We also designed and synthesized cyclic V3 glycopeptides that confirm the essence of a Man9/Man8GlcNAc2 glycan at the N332 site for PGT128 recognition. With the ability to reconstitute these glycopeptide epitopes via synthesis, we propose to design novel immunogens and hypothesize that displaying the glycopeptide epitopes on bacteriophage Qb (a well-characterized virus-like particle) in a highly ordered repetitive pattern will lead to immunogens capable of eliciting glycopeptide-specific neutralizing antibodies. We will test this hypothesis through pursuing three specific aims. Aim 1 is to design and synthesize Qb-based immunogens carrying polyvalent V1V2 and V3 glycopeptide epitopes. Construction of the immunogens includes chemoenzymatic synthesis of alkyne-glycopeptides and their subsequent conjugation with azide-tagged Qb via the copper-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction; Aim 2 is to evaluate the antigenicity of the synthetic immunogens by antibody binding studies; and Aim 3 is to evaluate the immunogenicity of the synthetic vaccines in rabbits. The anti-sera from immunized rabbits are analyzed by ELISAs and viral neutralization assays. These experiments will assess the magnitude, breadth and duration of neutralizing antibody responses from immunizations with the glycopeptide epitope-based immunogens. This study is likely to yield important new insights in the design of a truly effective HIV-1 vaccine.

描述（由申请人提供）：一种能够诱导广泛中和抗体的有效HIV疫苗仍然是打击HIV/AIDS流行病的重要目标。最近发现了由PG9，PG16，PGT121和PGT128代表的新型聚糖反应性广泛中和抗体（BNABS）的发现，揭示了基于新型表位的疫苗的设计。这些bnabs用明显的宽度和效能中和原发性HIV-1菌株，似乎靶向位于HIV-1 GP120的可变域（V1/V2或V3）中的糖肽表位。突变，生化和结构研究表明，PG9和PG16的表位是糖肽是由两个N-聚糖组成的（在N160和N160和N156/N173糖基化位点）和V1/V2域中的一组肽，而PGTAN 33 AT2和N3-GLYC28和GLYC的ESPITCES ATC12和GESPING涉及n3-glyc18 wistce wiste wis N301站点。然而，由于GP120的糖基化的异质性，聚糖特异性的进一步表征变得复杂。 We used a synthetic approach to constructing homogeneous V1V2 and V3 glycopeptides carrying defined glycans for further defining the glycan specificity, which led to the identification of a cyclic glycopeptide epitope carrying a Man5GlcNAc2 glycan at N160 and a sialylated N-glycan at N156/N173 site as the minimal epitopes for PG9/PG16。我们还设计和合成了循环V3糖肽，这些糖肽在N332位置确认了MAN9/MAN8GLCNAC2聚糖的本质，以识别PGT128。凭借通过合成重建这些糖肽表位的能力，我们建议设计新型免疫原子，并假设在噬菌体QB上显示糖肽的表位（一种特征良好的病毒样粒子（类似于良好的重复性）的重复性模式，将导致具有良好的重复性模型，从而导致免疫原化的倾向于具有较高的倾向于具有异化的糖果化剂。我们将通过追求三个具体目标来检验这一假设。目的1是设计和合成携带多价V1V2和V3糖肽表位的基于QB的免疫原。免疫原子的构建包括氯基 - 糖肽的化学合成及其随后通过铜催化的叠氮化叠氮化物 - 烷烃环载（CUAAC）与叠氮化物标记的QB的结合；目的2是通过抗体结合研究评估合成免疫原子的抗原性；目标3是评估兔子中合成疫苗的免疫原性。通过ELISA和病毒中和测定法分析了免疫兔的抗海洋。这些实验将评估用基于糖肽表位的免疫原子免疫的中和抗体反应的大小，广度和持续时间。这项研究可能会在设计真正有效的HIV-1疫苗的设计中产生重要的新见解。