Exploring antibody-Fc effector function in humanized mouse models of HIV latency

探索 HIV 潜伏期人源化小鼠模型中的抗体 Fc 效应子功能

• 批准号: 9050087
• 负责人: Priti Kumar
• 金额: $ 22.09万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-12-01 至 2017-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9050087
• 关键词: Animal Model; Anti-Retroviral Agents; Antibodies; Binding; Biological Assay; CCR5 gene; CD4 Positive T Lymphocytes; Capsid; Carrying Capacities; Cell Count; Cells; Code; Collaborations; Complement; Coupled; DNA; Dinitrophenols; Disease; Disease remission; Dose; Elements; Epitopes; Frequencies; Generations; Genomic DNA; Glycoproteins; Grant; HIV; HIV Infections; Human; Immune; Individual; Injection of therapeutic agent; Intramuscular; Investigation; Knowledge; Leukocytes; Life; Light; Measurement; Medicine; Modeling; Monitor; Mouse Strains; Mus; Muscle; Natural Killer Cells; Patients; Peripheral; Persons; Pharmaceutical Preparations; Phase; Plasma; Population; Prevention; Production; Proviruses; Recombinants; Recruitment Activity; Role; Serotyping; Skeletal Muscle; Surface; System; T memory cell; Testing; Tetanus Helper Peptide; Tetracyclines; Therapeutic; Therapeutic Effect; Time; Treatment Efficacy; Viral; Viral Load result; Viral reservoir; Viremia; antiretroviral therapy; base; college; complement system; expectation; gp160; gutless adenoviral vector; humanized mouse; interest; man; mouse model; neutralizing antibody; nonhuman primate; novel; novel strategies; peptidomimetics; peripheral blood; prevent; promoter; prophylactic; public health relevance; simian human immunodeficiency virus; small molecule; success; transgene expression

 DESCRIPTION (provided by applicant): There is currently considerable emphasis on strategies for eradicating HIV from infected individuals. Although much effort is focused on reactivating integrated provirus using small molecules, a second possibility is using broadly neutralizing antibodies (bNAbs) that are highly potent and active against diverse strains and clades of HIV. Recent evidence demonstrating the ability of bNAbs in delaying viral rebound after stopping antiretroviral treatment (ART) indicate that these antibodies may be able to clear or remove cells expressing envelope glycoprotein on their surface, effectively reducing the pool size of persistently-infected cells. We propose to investigate a role for bNAbs in actively eliminating or reducing the size of the persistent viral reservoir, in novel humanized models of ART-suppressed HIV infection that support antibody-effector function. In the first of three specific aims, we will construct `gutted' or helper-dependent adenoviral (HDAd) vectors, encoding the heavy and light chains of three second-generation bNAbs, in view of the downstream intramuscular application in animal models described in Aims 2 and 3. In the second aim, these vectored bNABs will be tested in HIV-infected humanized BLT mice, in which viral loads will be suppressed to undetectable levels by ART, for measurements of the latent viral pool size by genomic DNA qPCR and viral outgrowth assays. In particular, novel humanized mouse models that have active complement and functional natural killer cells will be used to assess the role of bNAb effector function in shrinking the persistently infected reservoir. In the final aim, the vectored bNAbs will be tested for their ability to shrink viral reservoirs in humanized mice derived using peripheral blood leukocytes from ART-suppressed HIV+ patients with undetectable plasma viral loads. On the basis of the investigations to be conducted in the R21 phase of this application, we anticipate establishing a critical role for bNAb-effector activit targeting persistent viral reservoirs. The R33 phase of the application will extend these studies to the testing of tetracycline-regulable bnAbs encoded in HDAds, possible due to large carrying capacity of HdAds (~30 kb). In addition to exploring newer, more potent bNAbs, we will also test the use of the recently described eCD4-Ig, that encodes both soluble CD4-Ig and a CCR5 peptidomimetic and ARM-Hs, which are bivalent small molecules capable of binding the CD4 binding pocket of gp160 and also recruiting anti-dinitrophenol antibodies for effector activity. This approach of using HDAds encoding bNAbs may also be combined with latency reversal agents, in order to clear out infected cells. The results of these investigations should accelerate the use of bNAbs as an adjunct to ART in the treatment of HIV disease, with the potential for functional eradication due to elimination or prevention of reactivation of persistently-infected cells.

 描述（由申请人提供）：目前非常重视从感染者身上根除艾滋病毒的策略。尽管很多努力都集中在使用小分子重新激活整合的原病毒上，但第二种可能性是使用广泛中和抗体 (bNAb)，它对不同的 HIV 毒株和分支具有高效和活性。最近的证据表明，bNAb 在停止抗逆转录病毒治疗 (ART) 后能够延迟病毒反弹，表明这些抗体可能能够清除或去除表面表达包膜糖蛋白的细胞，从而有效减少持续感染细胞的池大小。我们建议在支持抗体效应器功能的 ART 抑制 HIV 感染的新型人源化模型中，研究 bNAb 在主动消除或减少持久性病毒库大小方面的作用。 在三个具体目标中的第一个目标中，考虑到目标 2 和 3 中描述的动物模型中的下游肌肉注射应用，我们将构建“去内脏”或辅助依赖性腺病毒 (HDAd) 载体，编码三种第二代 bNAb 的重链和轻链。在第二个目标中，这些载体 bNAB 将在感染 HIV 的人源化 BLT 小鼠中进行测试，其中病毒载量 将被 ART 抑制至无法检测到的水平，以便通过基因组 DNA qPCR 和病毒生长测定来测量潜伏病毒池大小。特别是，具有活性补体和功能性自然杀伤细胞的新型人源化小鼠模型将用于评估 bNAb 效应器功能在缩小持续感染病毒库中的作用。 最终目标是测试载体 bNAb 缩小病毒库的能力。 使用来自 ART 抑制的 HIV+ 患者的外周血白细胞衍生的人源化小鼠，其血浆病毒载量无法检测到。 根据本申请 R21 阶段进行的研究，我们预计确定 bNAb 效应器活性针对持久病毒库的关键作用。该应用的 R33 阶段将把这些研究扩展到 HDAd 中编码的四环素可调节 bnAb 的测试，这可能是由于 HdAd 的大承载能力 (~30 kb) 所致。除了探索更新、更有效的 bNAb 之外，我们还将测试最近描述的 eCD4-Ig（编码可溶性 CD4-Ig 和 CCR5 肽模拟物）和 ARM-H（它们是二价小分子）的使用，它们是能够结合 gp160 的 CD4 结合袋并招募抗二硝基苯酚抗体以发挥效应活性的二价小分子。这种使用编码 bNAb 的 HDAd 的方法也可以与潜伏期逆转剂结合，以清除受感染的细胞。这些调查的结果应该会加速 使用 bNAb 作为 ART 的辅助治疗 HIV 疾病，由于消除或防止持续感染细胞的重新激活，有可能实现功能性根除。