Cow ultralong CDR3 antibodies targeting HIV gp120

靶向 HIV gp120 的牛超长 CDR3 抗体

• 批准号: 9141521
• 负责人: Vaughn Vasil Smider
• 金额: $ 29.81万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-02-01 至 2018-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9141521
• 关键词: Amino Acids; Antibodies; Antibody Diversity; Antibody Repertoire; Antibody Response; Antigens; Architecture; Binding; Biochemical; Cattle; Codon Nucleotides; Cysteine; Data; Disulfides; Epitopes; Fab Immunoglobulins; Genetic Engineering; Goals; HIV; HIV Antibodies; HIV Envelope Protein gp120; HIV Infections; HIV vaccine; Human; Immunization; Immunoglobulin Domain; Immunoglobulin G; Immunoglobulin Somatic Hypermutation; Immunoglobulins; Immunology; Lead; Length; Maps; Mediating; Monoclonal Antibodies; Mutagenesis; Mutation; Pattern; Polysaccharides; Positioning Attribute; Property; Serum; Structure; Structure-Activity Relationship; Surface; Surface Immunoglobulins; System; Texas; Trastuzumab; Vaccination; Vaccines; Viral; X-Ray Crystallography; base; complementarity-determining region 3; deep sequencing; design; disulfide bond; humanized antibody; improved; insight; neutralizing antibody; novel; public health relevance; response; structural biology; therapeutic development; tool

 DESCRIPTION (provided by applicant): A key feature of several anti-HIV neutralizing antibodies is the unusually long length of their CDR H3s. Cow antibodies are unique in having ultralong CDR3 regions that can be over 60 amino acids in length and are cysteine-rich. Crystal structures of two different antibody Fab fragments reveal that these CDR3s form a very unusual architecture composed of a long β-strand "stalk" which supports a disulfide rich "knob" that protrudes far from the immunoglobulin surface. Interestingly, different antibodies contain different patterns of disulfides, which result in different knob structures. Deep sequencing reveals extensive diversity in the ultralong CDR3s where a multitude of different disulfides could potentially form within the knob. Analysis of clonally derived sequences suggests that this diversity results from somatic hypermutation of an ultralong germline D region that has a severe codon bias towards mutation to cysteine. Thus, the bovine antibody system may produce an unprecedented repertoire of mega CDR3s that fold into an impressive diversity of minifolds containing combinations of somatically generated disulfides. We have immunized cows using the BG505 gp140 trimer and found that they are capable of making a robust and broadly neutralizing serum antibody response. In this exploratory proposal, we will take advantage of the unusual ultralong cow antibody repertoire to generate new monoclonal antibodies against HIV gp120 with the goal of identifying new neutralizing epitopes on HIV.

 描述（由适用提供）：几种抗HIV中和抗体的关键特征是其CDR H3S的罕见长度。牛抗体在具有长度超过60氨基酸且富含半胱氨酸的超过60个氨基酸的超过60多个氨基酸的区域方面是独一无二的。两种不同抗体Fab片段的晶体结构表明，这些CDR3形成了一个非常不寻常的结构，该结构由长β链的“茎”组成，该结构支持富含二硫化物的“旋钮”，该旋钮远离免疫球蛋白表面的突出。有趣的是，不同的抗体包含不同的二硫化物模式，从而导致不同的旋钮结构。深度测序揭示了超大的CDR3中广泛的多样性，其中许多不同的二硫化物可能会在旋钮内形成。对克隆衍生序列的分析表明，这种多样性是由于超大种系D区域的体细胞过度突破而引起的，该区域具有严重的密码子偏向于突变与半胱氨酸的突变。这是牛抗体系统可能会产生前所未有的巨型CDR3曲目，这些曲目将其折叠成令人印象深刻的微型杂质，其中包含体状产生的二硫化物的组合。我们使用BG505 GP140三聚体对母牛进行了免疫，发现它们能够做出可靠且广泛中和的血清抗体反应。在这项探索性建议中，我们将利用异常的超牛抗体库来生成针对HIV GP120的新单克隆抗体，目的是识别HIV上的新中和表位。