Design of Immunogens to Elicit PGT122 like Antibodies

设计免疫原以引发 PGT122 样抗体

基本信息

批准号：
9506647
负责人：
Isaac Jonathan Krauss
金额：
$ 42.4万
依托单位：
BRANDEIS UNIVERSITY
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：
2014-07-01 至 2020-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9506647
关键词：
Address Affinity Animal Model Antibodies Antibody Response Antigen Targeting Antigens B-Cell Activation B-Lymphocytes Binding Biophysics Carbohydrates Carrier Proteins Cell Culture Techniques Chemistry Codon Nucleotides Collaborations Complex Development Directed Molecular Evolution Elements Ensure Epitopes Evolution Family Germ Lines Glycobiology Glycopeptides Goals HIV HIV Antibodies HIV Envelope Protein gp120 HIV vaccine HIV-1 Immunity Immunization Individual Infection Knock-in Knock-in Mouse Libraries Link Macaca Mannose Messenger RNA Methods Mus Oryctolagus cuniculus Peptide Library Peptides Polysaccharides Ribosomes Specificity Stretching Structure Surface Technology Testing Vaccines Variant Viral base carbohydrate structure design immunogenic immunogenicity insight neutralizing antibody public health relevance reconstitution response success unnatural amino acids vaccine candidate vaccine development

项目摘要

DESCRIPTION (provided by applicant): Extensive study of HIV+ individuals in recent years has brought to light many examples of antibodies which can neutralize a broad range of HIV strains and protect against viral challenge in animal models of infection. One particularly promising antibody family, PGT121-123, has been shown to bind to an epitope involving a combination of V3 and V1 peptide together with several glycans, possibly of both high mannose and complex type. The goal of this project is to develop immunogens which mimic these glycopeptide structures, and test their ability to elicit antibodies with broadly-neutralizing, PGT122-like specificity. Because the glycan and peptide components of the PGT122 epitope are discontinuous within the gp120 primary sequence, it is quite challenging to design a single stretch of glycopeptide which could reconstitute all of the epitope elements in their native 3D orientation. To address this challenge, our group has developed a way to design glycopeptide epitope mimics by directed evolution. In Aim 1, we will adapt this method to the evolution of glycopeptides containing two different glycans, which will be useful for incorporation of both complex- and high mannose glycans into our glycopeptide libraries. In Aim 2, we will generate a library of ~10^13 random glycopeptides, then select and amplify those which bind best to PGT122. After multiple rounds of selection/amplification we will obtain glycopeptides which are very tightly recognized by PGT122. We will also do an analogous selection to obtain glycopeptides/peptides which are recognized by germline (gl) PGT122, and all promising constructs will be biophysically and structurally characterized. In Aim 3, we will then test the immunogenicity of PGT122 epitope mimics in rabbits. To address the possibility that bnAbs may only arise by evolving from the correct precursor germline antibodies, we will also conduct immunogenicity studies with the germline-targeted immunogens. In collaboration with David Nemazee at Scripps, we will investigate the ability of these constructs to activate gl-PGT122 B cells and stimulate a gl-PGT122 antibody response in knock-in mice.

描述（由申请人提供）：近年来对HIV+个体的广泛研究揭示了许多抗体的例子，这些抗体可以中和广泛的HIV菌株并在感染动物模型中预防病毒挑战。一种特别有前途的抗体家族PGT121-123已显示与涉及V3和V1肽以及几种Glycans的组合的表位结合，可能是高甘露糖和复杂类型。该项目的目的是开发模仿这些糖肽结构的免疫原子，并测试其以广泛中和pgt122类似于PGT122样特异性的抗体的能力。由于PGT122表位的聚糖和肽成分在GP120主要序列中是不连续的，因此设计一段糖肽的单个糖肽可以重新建立本天然3D方向的所有表位元素非常具有挑战性。为了应对这一挑战，我们的小组开发了一种通过定向进化来设计糖肽表位的方法。在AIM 1中，我们将这种方法适应包含两个不同聚糖的糖肽的进化，这将有助于将复合物和高甘露糖聚糖掺入我们的糖肽库中。在AIM 2中，我们将生成一个〜10^13随机糖肽的库，然后选择并放大与PGT122最好结合的培养基。经过多轮选择/扩增后，我们将获得PGT122非常紧密识别的糖肽。我们还将进行类似的选择，以获得通过种系（GL）PGT122识别的糖肽/肽，所有有前途的构建体将在生物物理和结构上表征。在AIM 3中，我们将测试兔子中PGT122表位的免疫原性。为了解决仅通过正确的前体种系抗体而发展出来的BNAB的可能性，我们还将使用靶向种系的免疫原子进行免疫原性研究。在Scripps与David Nemazee合作，我们将研究这些构建体激活GL-PGT122 B细胞并刺激敲入小鼠中GL-PGT122抗体反应的能力。