Project 2: Design and screening for immunogens to efficiently elicit anti-HIV-1 bNAbs

项目 2：设计和筛选免疫原以有效引发抗 HIV-1 bNAb

• 批准号: 10307762
• 负责人: Pamela J Bjorkman
• 金额: $ 63.6万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-02-10 至 2023-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10307762
• 关键词: Abbreviations; Adopted; Affinity; Animal Model; Animals; Antibodies; Antigens; B-Lymphocytes; Binding; Binding Sites; Clinical Trials; Collaborations; Complementarity Determining Regions; Complex; Cryoelectron Microscopy; Crystallization; Engineering; Enzyme-Linked Immunosorbent Assay; Genes; Goals; HIV; HIV Envelope Protein gp120; HIV vaccine; HIV-1; HIV-1 vaccine; Human; Immune response; Immunize; Immunoglobulin Genes; Immunoglobulin Somatic Hypermutation; Individual; Infection; Infection prevention; Knock-in; Knock-in Mouse; Length; Libraries; Light; Measures; Membrane; Memory B-Lymphocyte; Modeling; Molecular Sieve Chromatography; Mus; Mutate; Patients; Polysaccharides; Positioning Attribute; Production; Recombinants; Scheme; Structure; Surface Plasmon Resonance; V3 Loop; Vaccine Design; Vaccines; Variant; Viral; Wild Type Mouse; Work; Yeasts; base; design; env Gene Products; gp160; immunogenicity; improved; in vivo; mimetics; neutralizing antibody; nonhuman primate; prevent; rare variant; receptor binding; screening

Proj 2: Design and screening for immunogens to efficiently elicit anti-HIV-1 bNAbs PI: Pamela J. Bjorkman An effective HIV vaccine likely requires induction of Abs against HIV-1 Env that neutralize across the majority of circulating viral strains (broadly neutralizing antibodies; bNAbs). Because administered bNAbs are protective against HIV-1 infection in animal models, it is widely believed that a vaccine that elicits bNAbs would prevent infection. The fact that vaccine efforts have not yet succeeded preventing HIV-1 infection and/or eliciting bNAbs may relate to the observation that inferred germline (iGL) forms of bNAbs only rarely bind to Env proteins that are the targets of bNAbs. The germline targeting approach to vaccine design involves engineering an iGL-binding Env protein that preferentially activates bNAb precursors and selects productive somatic hypermutations (SHMs) during affinity maturation. Resulting memory B cells are then boosted by sequential immunogens to shepherd bNAb production by selecting additional productive SHMs. Drs. Bjorkman and Nussenzweig propose to apply this approach to target two classes of HIV-1 bNAb: a class related to PGT121 that binds to the base of the V3 variable loop and interacts with the N332gp120 glycan (V3/N332 bNAbs), and IOMA-like bNAbs, a new class of CD4-mimetic CD4 binding site (CD4bs) bNAbs derived from the VH1-2 germline gene segment. The V3/N332 and IOMA classes were chosen because (i) V3/N332 Abs are among the most potent of bNAbs, are commonly found in HIV-infected individuals who develop bNAbs, and immunogen studies will be complementary to human clinical trials evaluating passive delivery of the V3/N332 bNAb 10-1074 to HIV-1–infected patients, (ii) IOMA's relatively low number of SHMs and its normal-length CDRL3 suggest it may be more easily elicited than VRC01-class VH1-2–derived CD4bs bNAbs that are heavily somatically mutated and contain rare 5-residue CDRL3s, and (iii) immunogen design will be facilitated by the recent structure of a natively-glycosylated Env trimer bound to the V3/N332 bNAb 10-1074 and to IOMA. With the goal of creating SOSIP-based Env trimers to target iGLs and shepherd maturation of V3/N332 and IOMA-like bNAbs, Dr. Bjorkman proposes a highly collaborative project with Dr. Nussenzweig to (1) Solve structures of iGL–immunogen complexes to aid in structure-based immunogen design and library screens to select immunogens, (2) Use structure-based design combined with library screening to identify SOSIP trimers that bind V3/N332 iGLs with high affinity, (3) Use structural information to guide construction of a yeast display library to find rare variants that bind IOMA iGL with high affinity, (4) Combine results from Aims 2 and 3 to create SOSIP-based immunogens that bind iGLs of both bNAbs and evaluate them in wildtype mice and in mice produced by Dr. Nussenzweig to carry germline-reverted versions of IOMA and 10-1074. These aims will be repeated using information from new structures, library screens, and screens for Abs isolated by Dr. Nussenzweig from HIV-naïve individuals and from sequentially-immunized animals.

ProJ 2：免疫原子的设计和筛查有效地引起抗HIV-1 BNABS PI：Pamela J. Bjorkman 有效的HIV疫苗可能需要对HIV-1 ENV诱导ABS，以中和大多数 循环病毒菌株（广泛中和抗体； bnabs）。因为管理的bnab受到保护 反对动物模型中的HIV-1感染，人们普遍认为引起BNAB的疫苗会阻止 感染。疫苗努力尚未成功防止HIV-1感染和/或引起的事实 BNAB可能与观察到的观察结果相关，即推断生殖线（IgL）形式的BNAB很少与Env结合 是BNAB靶标的蛋白质。疫苗设计的种系靶向方法涉及工程 优先激活BNAB前体并选择生产性体细胞的IGL结合env蛋白 亲和力成熟期间的高压（SHM）。然后通过顺序增强产生的内存B单元 通过选择其他生产性SHM，可以免疫对牧羊人BNAB生产。博士。 Bjorkman和 Nussenzweig提议将这种方法应用于两个类别的HIV-1 BNAB：与PGT121相关的类 结合V3变量循环的底部并与N332GP120 Glycan（V3/N332 BNAB）和 ioma样bnabs，一种新的CD4模拟CD4结合位点（CD4BS）BNAB，源自VH1-2 种系基因段。选择V3/N332和IOMA类是因为（I）V3/N332 ABS之一 BNAB的最潜力，通常是在开发BNAB的HIV感染者中发现的，并且 免疫原研究将完成评估V3/N332的被动递送的人类临床试验 BNAB 10-1074至HIV-1感染的患者，（ii）Ioma的SHM数量相对较少及其正常长度 CDRL3表明它可能比VRC01级VH1-2衍生的CD4BS BNAB更容易引起 大量的体外突变并包含罕见的5个残留的CDRL3，并且（iii）将准备免疫原的设计 通过与V3/N332 BNAB的最新结构 ioma。目的是创建基于SOSIP的Env Trimers以靶向IgL和V3/N332的牧羊人成熟 Bjorkman博士和Ioma Like Bnabs提议与Nussenzweig博士进行高度协作的项目（1） 求解Igl-免疫原子络合物的结构，以帮助基于结构的免疫原设计和文库 选择免疫原的屏幕，（2）使用基于结构的设计与库筛选一起识别 将V3/N332 Igl绑定具有高亲和力的SOSIP三聚体，（3）使用结构信息指导构造 酵母展示库可以找到与高亲和力结合ioma Igl的稀有变体，（4）结合了目标的结果 2和3创建基于SOSIP的免疫原，以结合两种BNAB的IgL并在WildType小鼠中进行评估 在由Nussenzweig博士生产的小鼠中，携带了ioma生殖线版本和10-1074。这些 将使用来自新结构，库屏幕和屏幕的ABS隔离的信息重复目标 来自未经HIV的个体和依次免疫动物的Nussenzweig博士。