Mechanisms of adenovirus neutralization

腺病毒中和机制

基本信息

批准号：
10264157
负责人：
PHOEBE L STEWART
金额：
$ 70.01万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-06-01 至 2025-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10264157
关键词：
Acute Address Adenovirus Vector Adenoviruses Animals Antigen-Antibody Complex Antiviral Agents Antiviral Response Attenuated Binding Biological Blood Blood Coagulation Factor Cancer Patient Cell Compartmentation Cells Cessation of life Clinical Clinical Trials Coagulation Process Complement Complement Receptor Complex Cryo-electron tomography Defense Mechanisms Development Disseminated Malignant Neoplasm Distant Dose-Limiting Enrollment Ensure Exhibits Fc Receptor Funding Gene Transfer Generations Genetic Diseases Hematopoietic stem cells Hepatocyte Hepatotoxicity High Prevalence Human Humoral Immunities Immune Immune response Immune system Immunity Immunization Immunoglobulin M Immunologics Infection Inflammation Inflammatory Inflammatory Response Infusion procedures Innate Immune System Intervention Intravenous Iron Knowledge Malignant Neoplasms Mediating Modeling Molecular Mus Natural Immunity Patients Phagocytes Pharmacology Phylogenetic Analysis Population Prevalence Production Property Research Personnel Role Safety Sampling Science Serotyping Serum Signal Pathway Structure System Therapeutic Therapeutic Intervention Virus Virus Inactivation adaptive immunity arm base cancer therapy cell type clinical application clinical development clinical practice cytokine improved in vivo insight intravenous administration macrophage neutralizing antibody novel novel strategies oncolytic vector patient stratification public health relevance receptor response sample fixation systemic inflammatory response systemic toxicity therapeutic development therapeutic gene tool vector virtual delivery

项目摘要

ABSTRACT Intravascular administration of adenovirus (Ad) vectors holds great promise for improving survival of patients with disseminated metastatic cancer and ameliorating numerous genetic diseases through permanent correction of the hematopoietic stem cell compartment. Although potentially advantageous, intravascular delivery makes therapeutic Ads vulnerable to humoral components of the innate and adaptive arms of the immune system. Extensive previous analyses by us and others showed that binding of coagulation FX to HAdv-5-based vectors in the blood facilitates highly efficient hepatocyte transduction, triggering hepatotoxicity. Furthermore, a relatively high prevalence of HAdv-5-neutralizing antibodies (NAbs) in the human population, prompted active development of therapeutic vectors based on alternate Ad serotypes that don't interact with FX and exhibit low NAb prevalence. Our preliminary studies indicate however, that both pre-existing neutralizing and non- neutralizing humoral immunity can significantly exacerbate the host inflammatory antiviral response. We found that the majority of human sera that lack HAdv-5-neutralizing activity are still able to trigger complement fixation on the virus, leading to potentiated inflammatory cytokine production by immune cells. Moreover, we found that immunization of mice with adenovirus HAdv-11 triggers generation of non-neutralizing antibodies, which are highly efficient at complement fixation on phylogenetically-distant HAdv-5 virus. Based on these findings, we propose a novel concept of cryptic opsonizing non-neutralizing antibodies, or CON-Abs, which bind to Ad after systemic delivery, trigger complement fixation on the virus, and target Ad-immune complexes (Ad-ICs) to immune phagocytic cells, leading to drastically potentiated systemic inflammation. The molecular mechanisms mediating the immune-stimulatory properties of pre-existing non-neutralizing immunity and its effect on the safety of systemic Ad delivery are virtually unknown. Therefore, in Specific Aim 1 of this project we will analyze how phylogenetically-distant HAdv serotypes trigger generation of CON-Abs to HAdv-5. In Specific Aim 2, we will determine the structural bases for CON-Ab-mediated complement fixation on the virus and complement- mediated virus neutralization. In Specific Aim 3 we will determine specific cell types and their receptors that sequester Ad-ICs in vivo; and in Specific Aim 4 we will determine specific signaling pathways responsible for the exacerbated inflammatory response to Ad-ICs and develop targeted pharmacological approaches to improve the safety of systemic Ad delivery in gene transfer and cancer therapy models. The proposed studies will provide new mechanistic insights into fundamental functions of innate and adaptive immunity and host anti-viral defense, as well as allow for the development of novel patient stratification tools and pharmacological approaches to improve the safety of clinical interventions that rely on systemic delivery of therapeutic Ads.

抽象的腺病毒（Ad）载体的血管内给药对于改善患者的生存具有巨大的希望患有播散性转移性癌症并通过永久矫正改善多种遗传性疾病造血干细胞室的结构。尽管具有潜在的优势，但血管内输送使得治疗广告容易受到免疫系统先天性和适应性臂的体液成分的影响。我们和其他人之前进行的大量分析表明，凝血 FX 与基于 HAdv-5 的载体的结合在血液中促进高效肝细胞转导，引发肝毒性。此外，相对 HAdv-5 中和抗体 (NAb) 在人群中的高流行率，促使积极基于不与 FX 相互作用且表现出低水平的替代 Ad 血清型的治疗载体的开发 NAB 患病率。然而，我们的初步研究表明，预先存在的中和和非中和体液免疫可显着加剧宿主炎症抗病毒反应。我们发现大多数缺乏 HAdv-5 中和活性的人类血清仍然能够触发补体结合作用于病毒，导致免疫细胞增强炎症细胞因子的产生。此外，我们发现用腺病毒 HAdv-11 免疫小鼠会引发非中和性抗体的产生，这些抗体是对系统发育较远的 HAdv-5 病毒的补体固定非常有效。基于这些发现，我们提出了一种神秘的调理非中和抗体（CON-Abs）的新概念，它在全身递送，触发补体对病毒的固定，并靶向 Ad 免疫复合物 (Ad-IC) 免疫吞噬细胞，导致全身炎症急剧增强。分子机制介导预先存在的非中和免疫的免疫刺激特性及其对安全性的影响系统性广告投放的具体情况几乎是未知的。因此，在本项目的具体目标 1 中，我们将分析如何系统发育上较远的 HAdv 血清型触发 HAdv-5 的 CON-Ab 的产生。在具体目标 2 中，我们将确定 CON-Ab 介导的补体固定在病毒和补体上的结构基础介导的病毒中和。在特定目标 3 中，我们将确定特定的细胞类型及其受体，体内隔离 Ad-IC；在具体目标 4 中，我们将确定负责加剧了对 Ad-IC 的炎症反应，并开发有针对性的药理学方法来改善基因转移和癌症治疗模型中系统性广告递送的安全性。拟议的研究将提供对先天性和适应性免疫以及宿主抗病毒防御的基本功能的新机制见解，以及允许开发新的患者分层工具和药理学方法提高依赖系统性治疗性广告的临床干预的安全性。