Structural Basis of Antibody-Mediated Neutralization of HIV

描述（由申请人提供）：对抗HIV-1的策略需要抗体如何识别HIV包膜蛋白以及免疫系统如何使用它们来消除病毒和病毒感染细胞的结构知识。直到最近，只有少数的广泛中和抗体（bNAb）对HIV-1的特点和免疫学基础的广度和效力仍然知之甚少。全面了解抗体如何中和HIV的一个重要障碍是单克隆bNAb的可用性有限。通过从产生高滴度的广泛中和活性的患者的B细胞中分离HIV抗体的新方法解决了这个问题。 Michel Nussenzweig博士的实验室最近分离的几种抗体，包括NIH 45 -46、3BNC 117和3BNC 60，显示出比VRC 01更上级的效力和广度，VRC 01是以前最好的bNAb。我们最近解决了与gp 120结合的NIH 45 -46的结构，并使用基于结构的设计将其效力提高至少10倍，使NIH 45 - 46 G54 W成为目前可用的最有效的抗HIV bNAb。我们将与Nussenzweig博士合作，确定新bNAb的可变Fab从新供体中分离时广泛和有效中和的结构相关性。对bNAb抗HIV功效的基本知识将促进优化用于通过免疫或基因治疗被动递送的天然人单克隆抗体的广度和效力，并提供开发将引发bNAb的主动免疫策略所需的基础框架。1）解析bNAb Fab和bNAb Fab-gp 120复合物的晶体结构，以确定广泛和有效的HIV中和的基本特征。2)生产具有增强中和活性的天然抗体变体。 与公共卫生的关系：艾滋病毒/艾滋病仍然是当前对全球公共卫生的最重要威胁之一。至少有6 000万人感染了艾滋病毒，其中近一半已经死亡。虽然抗逆转录病毒药物在发达国家有效，但发展中国家迫切需要疫苗和/或预防感染的新方法。我们将系统地分析新的抗HIV抗体，目的是了解其保护机制，并改进被动递送预防策略的抗体。

DESCRIPTION (provided by applicant): Strategies to combat HIV-1 require structural knowledge of how antibodies recognize HIV envelope proteins and how they are used by the immune system to eliminate viruses and virally-infected cells. Until recently, only a small number of broadly neutralizing antibodies (bNAbs) against HIV-1 had been characterized and the immunological basis for their breadth and potency remains poorly understood. One important obstacle to a comprehensive understanding of how antibodies neutralize HIV was the limited availability of monoclonal bNAbs. This issue was resolved by new methods for HIV antibody isolation from B cells of patients who produce high titers of broad neutralizing activity. Several of the antibodies recently isolated by Dr. Michel Nussenzweig's laboratory, including NIH45-46, 3BNC117 and 3BNC60, show superior potency and breadth to VRC01, previously the best bNAb. We recently solved the structure of NIH45-46 bound to gp120, and used structure-based design to increase its potency by at least 10-fold, making NIH45-46G54W the most potent anti- HIV bNAb currently available. We will collaborate with Dr. Nussenzweig to determine the structural correlates of broad and potent neutralization by the variable Fabs of new bNAbs as they are isolated from new donors. Basic knowledge of bNAb efficacy against HIV will facilitate optimization of the breadth and potency of natural human monoclonal antibodies for passive delivery by immunization or gene therapy and provide to the underlying framework needed to develop active immunization strategies that will elicit bNAbs. The following specific aims will be pursued: 1) Solve crystal structures of bNAb Fabs and bNAb Fab-gp120 complexes to define the essential features of broad and potent HIV neutralization. 2) Produce natural antibody variants with enhanced activity in neutralization. PUBLIC HEALTH RELEVANCE: HIV/AIDS remains one of the most important current threats to global public health. At least 60 million people have been infected with HIV, of which almost half have died. Although anti-retroviral drugs have been effective in the developed world, a vaccine and/or new methods to prevent infections are urgently needed in the developing world. We will systematically analyze new anti-HIV antibodies with goals of understanding their protective mechanisms and improving antibodies for passive delivery prevention strategies.