Antibody-based therapeutics and vaccines against AIDS

基于抗体的艾滋病疗法和疫苗

• 批准号: 9343820
• 负责人: Dimiter S Dimitrov
• 金额: $ 30.32万
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/9343820
• 关键词: Acquired Immunodeficiency Syndrome; Address; Affect; Amino Acids; Anti-Retroviral Agents; Antibodies; Binding; Binding Sites; Cells; Chimeric Proteins; Clinical; Development; Disease; Drug Kinetics; Drug resistance; Engineering; Fc Immunoglobulins; Generations; Glycoproteins; Goals; HIV; HIV-1; Half-Life; Heterodimerization; Human; IgG1; Immunoglobulin Constant Region; Infection; Libraries; Light; Mus; Mutation; Phage Display; Pharmaceutical Preparations; Property; Proteins; Proteolysis; Reporting; Serum; Structure; Technology; Therapeutic; Therapeutic Uses; Toxic effect; Variant; Viral; Virus; base; design; flexibility; in vivo; inhibitor/antagonist; neonatal Fc receptor; novel therapeutics; polypeptide; prevent; receptor; scaffold; therapeutic vaccine

A major accomplishment for this year is described below. We previously described 4Dm2m, an exceptionally potent broadly neutralizing CD4-antibody fusion protein against HIV-1. It was generated by fusing the engineered single human CD4 domain mD1.22 to both the N and C termini of the human IgG1 heavy chain constant region and the engineered single human antibody domain m36.4, which targets the CD4-induced coreceptor binding site of the viral envelope glycoprotein, to the N terminus of the human antibody kappa light chain constant region via the (G4S)3 polypeptide linkers. However, therapeutic use of 4Dm2m was limited by its short in vivo half-life. We showed that a combination of three approaches have successfully increased the persistence of 4Dm2m in mice. First, to stabilize the scaffold, we enhanced heterodimerization between the heavy chain constant domain 1 (CH1) and kappa light chain constant domain (CK) by using structure-guided design and phage-display library technologies. Second, to address the possibility that long polypeptide linkers might render fusion proteins more susceptible to proteolysis, we shortened the (G4S)3 linkers or replaced them with the human IgG1 hinge sequence, which is naturally designed for both flexibility and stability. Third, we introduced two amino acid mutations into the crystallizable fragment (Fc) of the scaffold previously shown to increase antibody binding to the neonatal Fc receptor (FcRn) and prolong half-lives in vivo. Collectively, these approaches markedly increased the serum concentrations of 4Dm2m in mice while not affecting other properties of the fusion protein. The new 4Dm2m variants are promising candidates for clinical development to prevent or treat HIV-1 infection. To our knowledge, this is the first report on stabilized CH1-CK, which is potentially useful as a new heterodimerization scaffold for generation of bispecific and multispecific antibodies or proteins with a more favorable pharmacokinetic profile.

下面介绍今年的主要成就。我们之前描述过 4Dm2m，这是一种针对 HIV-1 的极其有效的广泛中和 CD4 抗体融合蛋白。它是通过将工程单人 CD4 结构域 mD1.22 融合到人 IgG1 重链恒定区的 N 和 C 末端以及工程单人抗体结构域 m36.4 生成的，该结构域靶向 CD4 诱导的辅助受体结合位点病毒包膜糖蛋白通过 (G4S)3 多肽接头连接至人抗体 kappa 轻链恒定区的 N 末端。然而，4Dm2m 的治疗用途因其体内半衰期短而受到限制。我们证明，三种方法的组合已成功提高 4Dm2m 在小鼠体内的持久性。首先，为了稳定支架，我们通过使用结构引导设计和噬菌体展示库技术增强了重链恒定域 1 (CH1) 和 kappa 轻链恒定域 (CK) 之间的异二聚化。其次，为了解决长多肽接头可能使融合蛋白更容易蛋白水解的可能性，我们缩短了 (G4S)3 接头或用人 IgG1 铰链序列替换它们，该序列天然设计用于灵活性和稳定性。第三，我们在支架的可结晶片段（Fc）中引入了两个氨基酸突变，先前显示这会增加抗体与新生儿Fc受体（FcRn）的结合并延长体内半衰期。总的来说，这些方法显着增加了小鼠体内 4Dm2m 的血清浓度，同时不影响融合蛋白的其他特性。新的 4Dm2m 变体是用于预防或治疗 HIV-1 感染的临床开发的有希望的候选者。据我们所知，这是关于稳定化 CH1-CK 的第一份报告，它可能可用作新的异二聚化支架，用于生成具有更有利的药代动力学特征的双特异性和多特异性抗体或蛋白质。