Structure and Immunogenicity of Cleaved, Stabilized HIV-1 Envelope Trimers

切割、稳定的 HIV-1 包膜三聚体的结构和免疫原性

• 批准号: 7645919
• 负责人: WILLIAM C OLSON
• 金额: $ 286.05万
• 依托单位: PROGENICS PHARMACEUTICALS, INC.
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-15 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7645919
• 关键词: Structure; Immunogenicity; Cleaved; Stabilized; HIV

DESCRIPTION (provided by applicant): This HIVRAD program merges the complementary expertise of leading HIV-1 researchers in order to provide a fundamental advance towards an HIV-1 vaccine than can elicit broadly neutralizing antibodies (NAbs). This innovative program comprises two Research Projects: HIV-1 Env Vaccine Design (Dr. John Moore, Cornell University) and HIV-1 Trimer Crystallography (Dr. Ian Wilson, The Scripps Research Institute). The Projects are supported by scientific and administrative Cores (Dr. William Olson, Progenies Pharmaceuticals). This program leverages our recent successes in generating stable, proteolytically mature gp140 trimers (SOSIP gp140s) that mimic virion-associated Env in topology and antigenicity. As immunogens, SOSIP trimers have proven to be superior to matched gp120s in eliciting NAbs in animals. In the HIVRAD, the SOSIP template will be tailored for structural studies and for further improvements in immunogenicity in animals. Our overall goals of the HIVRAD are reflected in three major milestones: 1) determine the structure of cleaved env trimers at <4A resolution, 2) demonstrate methods to overcome HIV-1 Env's immunosuppressive properties, and 3) identify a SOSIP trimer vaccine that elicits heterologous neutralization of diverse HIV-1 isolates. Given the present rudimentary knowledge of trimer structure, an atomic-level view has the potential to spur development of a new generation of rationally designed Env vaccines, and our preliminary studies on crystallizing SOSIP trimers provide high enthusiasm and guarded optimism for success. Parallel studies will evaluate SOSIP trimers that have been modified so as to improve presentation of NAb epitopes and/or remove Env immunosuppressive features. Animal immunogenicity studies will be complemented with in vitro studies that compare modified and unmodified forms of Env for their ability to elicit immunosuppressive responses in human DCs. In addition to the primary Projects and Cores, the HIVRAD includes additional leading academic and corporate collaborators who lend specialized expertise in the areas of vaccine delivery (Aldevron, Inc.), NAb analyses (Monogram Biosciences), NAb specificity analyses (Dr. James Binley), in vitro immunogenicity studies (VaxDesign), and exploratory immunogenetics (Dr. Sunil Ahuja). Our shared goal is to overcome key structural and immunological challenges to developing a successful Env-based HIV-1 vaccine. PROJECT 1: HIV-1 Env Vaccine Design (Moore, J) PROJECT 1 DESCRIPTION (provided by applicant): The goal of Project 1 of the HIVRAD is to design vaccines intended to induce NAbs, based on accumulated and emerging knowledge of structure-function relationships within the HIV-1 Env complex and of how Env proteins interact with cells of the immune system, in vitro and in vivo. We propose three inter-related Specific Aims. Aim 1: To further modify the amino acid sequence of HFV-1 envelope glycoproteins. to create novel forms that improve the immunogenicity of neutralization epitopes and facilitate structural studies. We will build on the SOSIP method for making stable, cleaved gp!40 trimers, by identifying and testing additional substitutions that stabilize gp41-gp41 interactions, by introducing other sequence changes into gp!20 and/or gp41 that are intended to create or better expose NAb epitopes, and by eliminating immunosuppressive regions of the Env complex. The latter studies will be coordinated with research outlined in Aim 2, and will lead to the creation of new immunogens for testing in small animals in Aim 3, and also in the MIMIC system within Core B. We will also make modifications to Env trimers that are intended to reduce protein heterogeneity and/or flexibility, and thereby facilitate X-ray crystallography studies to be conducted by Ian Wilson (Project 2). Aim 2: To study in vitro how to overcome immunosuppressive effects of gp120 by the use of adjuvants and TLR activators. We will study the immunosuppressive effects of the mannose moieties of gp120 glycans in vitro, using both human and murine cell-based systems, particularly dendritic cells (DCs). The abilities of TLR activators and other adjuvant-associated molecules to overcome these adverse effects will then be tested. We will, in addition, collaborate with the groups headed by Eric Mishkin and Sunil Ahuja, to derive additional immunologic and genetic information using the VaxDesign MIMIC system (Core B). The outcome of these experiments will facilitate the construction of new immunogens in Aim 1, and the rational design of immunization regimens in Aim 3 and Core B that are intended to maximize the antibody response to Env. Aim 3: To evaluate the immunogenicity of modified Env trimers in small animals. We will design and evaluate rabbit and mouse immunization studies that will be conducted within Core B, to determine whether the various modifications to Env glycoproteins that we identified and evaluated in Aims 1 and 2, can alter the immune response to these and co-administered antigens. We will also compare the immunogenicity of Envproteins with other antigens, alone and co-administered, to determine whether Env proteins can suppress or modify immune responses, including the IgG subclass pattern, to themselves and other antigens (HTV-1 derived or unrelated). The design of some experiments will also take into account information on adjuvants and TLR activators generated in Aim 2 and by using the VaxDesign MIMIC system in Core B. In an iterative process, the immunization experiments will themselves guide the design of additional studies to be carried out by VaxDesign using the MIMIC system (see Core B). The overall outcome of these various studies will help design additional Env sequence modifications in Aim 1 that are intended to further improve immunogenicity or eliminate the causes of immunosuppression.

描述（由申请人提供）：该HIVRAD计划融合了领先的HIV-1研究人员的互补专业知识，以便为HIV-1疫苗提供根本性的进步，而不是引发广泛中和抗体（NAb）。该创新项目包括两个研究项目：HIV-1 Env疫苗设计（John摩尔博士，康奈尔大学）和HIV-1三聚体晶体学（Ian Wilson博士，斯克里普斯研究所）。这些项目得到了科学和行政核心（William Olson博士，Progenies Pharmaceuticals）的支持。该计划利用了我们最近在产生稳定的、蛋白水解成熟的gp 140三聚体（SOSIP gp 140 s）方面的成功，该三聚体在拓扑结构和抗原性上模拟病毒体相关的Env。作为免疫原，SOSIP三聚体已被证明在动物中诱导NAb方面上级匹配的gp 120。在HIVRAD中，将定制SOSIP模板用于结构研究和进一步改善动物免疫原性。我们的HIVRAD的总体目标反映在三个主要里程碑中：1）确定<4 A分辨率的切割的env三聚体的结构，2）证明克服HIV-1 Env的免疫抑制特性的方法，和3）鉴定增强不同HIV-1分离株的异源中和的SOSIP三聚体疫苗。鉴于目前三聚体结构的基本知识，原子水平的观点有可能刺激新一代合理设计的Env疫苗的开发，我们对结晶SOSIP三聚体的初步研究提供了高度的热情和谨慎的乐观。平行研究将评估已经修饰的SOSIP三聚体，以改善NAb表位的呈递和/或去除Env免疫抑制特征。动物免疫原性研究将补充体外研究，比较修饰和未修饰形式的Env在人DC中引发免疫抑制应答的能力。除了主要的项目和核心之外，HIVRAD还包括其他领先的学术和企业合作者，他们在疫苗交付领域提供专业知识（Aldevron，Inc.），NAb分析（Monogram Biosciences）、NAb特异性分析（James Binley博士）、体外免疫原性研究（VaxDesign）和探索性免疫遗传学（Sunil Ahuja博士）。我们的共同目标是克服关键的结构和免疫挑战，以开发成功的基于Env的HIV-1疫苗。 项目1：HIV-1 Env疫苗设计（摩尔，J） 项目1描述（由申请方提供）：HIVRAD项目1的目标是基于HIV-1 Env复合物内结构-功能关系以及Env蛋白如何与免疫系统细胞在体外和体内相互作用的累积和新兴知识，设计预期用于诱导NAb的疫苗。我们提出了三个相互关联的具体目标。目的1：进一步改造HFV-1包膜糖蛋白的氨基酸序列。以创造新的形式，提高中和表位的免疫原性和促进结构研究。我们将在SOSIP方法的基础上制备稳定的切割gp！40三聚体，通过鉴定和测试额外的取代，稳定gp 41-gp 41相互作用，通过引入其他序列变化到gp！20和/或gp 41，旨在产生或更好地暴露NAb表位，并通过消除Env复合物的免疫抑制区域。后一项研究将与目标2中概述的研究协调，并将导致创建新的免疫原，用于目标3中的小动物试验，以及核心B中的MIMIC系统。我们还将对Env三聚体进行修改，以减少蛋白质的异质性和/或灵活性，从而促进Ian Wilson（项目2）进行的X射线晶体学研究。目的2：研究免疫佐剂和TLR激活剂对gp 120免疫抑制作用的抑制作用。我们将研究gp 120聚糖的甘露糖部分在体外的免疫抑制作用，使用人类和小鼠细胞为基础的系统，特别是树突状细胞（DC）。然后将测试TLR激活剂和其他促排剂相关分子克服这些不利影响的能力。此外，我们将与Eric Mishkin和Sunil Ahuja领导的小组合作，使用VaxDesign MIMIC系统（核心B）获得更多的免疫学和遗传学信息。这些实验的结果将有助于在目标1中构建新的免疫原，以及在目标3和核心B中合理设计旨在最大化对Env的抗体应答的免疫方案。目的3：评价修饰的Env三聚体在小动物体内的免疫原性。我们将设计和评价在核心B中进行的兔和小鼠免疫研究，以确定我们在目的1和2中鉴定和评价的Env糖蛋白的各种修饰是否可以改变对这些和共同给药抗原的免疫应答。我们还将比较Env蛋白与其他抗原（单独和共同施用）的免疫原性，以确定Env蛋白是否可以抑制或改变对自身和其他抗原（HIV-1衍生或无关）的免疫应答，包括IgG亚类模式。一些实验的设计还将考虑Aim 2中生成的佐剂和TLR激活剂的信息，以及使用核心B中的VaxDesign MIMIC系统生成的佐剂和TLR激活剂的信息。在迭代过程中，免疫实验本身将指导VaxDesign使用MIMIC系统进行的其他研究的设计（参见核心B）。这些不同研究的总体结果将有助于设计目标1中的额外Env序列修饰，其旨在进一步改善免疫原性或消除免疫抑制的原因。