Optimizing Immunity and Maternal Host Defense Against Congenital Cytomegalovirus Infection

优化免疫和母体宿主防御先天性巨细胞病毒感染的能力

• 批准号: 10434692
• 负责人: ADAM P. GEBALLE
• 金额: $ 62.92万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10434692
• 关键词: Ablation; Adjuvant; Animals; Antibodies; Antigens; Antiviral Response; Attenuated; Attenuated Vaccines; Bacterial Artificial Chromosomes; Birth; Body Weight decreased; Cavia; Cell Culture Techniques; Cells; Clinical; Clinical Trials; Collaborations; Communicable Diseases; Complex; Contracts; Cyclic AMP-Dependent Protein Kinases; Cytomegalovirus; Cytomegalovirus Infections; Cytomegalovirus Vaccines; DNA biosynthesis; Development; Disabled Persons; Disease; Double-Stranded RNA; Enzyme-Linked Immunosorbent Assay; Equilibrium; Female of child bearing age; Gene Expression; Generations; Genes; Genome; Goals; Growth; Guinea pig cytomegalovirus; Host Defense; Human; Immediate-Early Proteins; Immune; Immune Evasion; Immune response; Immunity; Immunization; Immunize; Immunocompetent; Immunocompromised Host; Immunoglobulin G; Immunologics; Infant; Infection; Inflammatory; Interferon Type II; Interferons; Kinetics; Knock-out; Lead; Ligands; MF59; MHC Class I Genes; Modeling; Murid herpesvirus 1; Natural Immunity; Nucleic Acids; Pathogenesis; Pathway interactions; Pregnancy; Pregnancy Outcome; Pregnant Women; Preventive vaccine; Primary Infection; Production; Proteins; Recombinants; Role; Safety; Sensorineural Hearing Loss; Study models; Subunit Vaccines; Techniques; Testing; Uncertainty; United States; Vaccination; Vaccine Adjuvant; Vaccine Design; Vaccines; Vertical Disease Transmission; Viral; Viral Proteins; Viremia; Virulent; Virus; Virus Diseases; Virus Replication; Woman; Work; antagonist; attenuation; clinically relevant; congenital cytomegalovirus; congenital infection; cytokine; design; disability; enzyme linked immunospot assay; functional outcomes; guinea pig model; immunogenic; immunogenicity; immunoregulation; improved; in vivo; maternal vaccination; novel; overexpression; pregnant; prevent; programs; protective efficacy; protein kinase R; public health priorities; public health relevance; rational design; reconstitution; response; sensor; seropositive; transmission process; vaccine candidate; vaccine development; vaccine efficacy; vaccine immunogenicity; vaccine strategy

ABSTRACT Development of an effective preventative vaccine against human cytomegalovirus (HCMV) for women of childbearing age is a major public health priority. Subunit vaccines are in clinical trials, but uncertainty exists about optimal platforms and correlates of protection. Live, attenuated vaccines may induce a broader repertoire of immune responses, but striking the balance between safety and immunogenicity is challenging. The long-term goal of this ongoing collaboration is to use the guinea pig cytomegalovirus (GPCMV) model to test hypotheses about optimal design of safe and effective vaccines against congenital infection. We recently discovered that inclusion of a pentameric complex (PC), consisting of the GPCMV gH, gL and GP129, 131 and 133 (homologs of the HCMV PC), enabled generation of a live, attenuated vaccine that was protective against congenital GPCMV transmission, but the vaccine was unacceptably virulent. In parallel studies we observed that viral challenge of pregnant dams with preconception immunity to the prototypical GPCMV strain 22122 with a heterologous `clinical isolate', the CIDMTR strain, resulted in both maternal re-infection and congenital transmission of the new challenge strain. These findings, as well as clinical observations in HCMV-infected women, suggest that a vaccine may need to perform better than `natural immunity' in order to protect against reinfection. We hypothesize that a rationally designed, PC-intact, but disabled infectious single cycle (DISC) vaccine will provide superior protective immunity, including against re-infection, compared to subunit gB and to `natural' immunity. In Aim 1, we test this hypothesis by comparing a PC-positive vaccine, attenuated by deletions of GPCMV-encoded MHC I homologs and a viral protein kinase R (PKR) evasin, versus MF59- adjuvanted recombinant gB. We will examine the magnitude of protection after both primary maternal infection and re-infection of dams with preconception immunity following challenge with a heterologous strain during pregnancy. We will further optimize CMV vaccines in Aim 2 by developing DISC vaccines, using a PC-intact virus with destabilizing domains fused to essential viral proteins. In contrast to HCMV vaccines in clinical trials, we hypothesize that DISC vaccines in which viral replication is blocked downstream of DNA replication will progress to late gene expression and produce a broader array of immunogenic proteins. Aim 3 will evaluate whether deletion of viral antagonists of host cell defenses such as protein kinase R (PKR) can aid in vaccine design. We will test the hypothesis that GPCMV encodes a second PKR antagonist, elimination of which would be expected to generate a safe and effective vaccine. In addition, we will overexpress dsRNA in the vaccine construct with the aim of improving safety and immunogenicity. Vaccines will be evaluated for attenuation and immunogenicity and optimized vaccines will be used to identify immune correlates of protection, including non- neutralizing functions of IgG. Our studies will explore the overarching hypothesis that immunity conferred by a CMV vaccine can be superior to `natural' preconception immunity, a highly relevant issue for HCMV vaccines.

抽象的 为女性开发针对人类巨细胞病毒（HCMV）的有效预防疫苗 育龄是一项重要的公共卫生优先事项。亚单位疫苗正在进行临床试验，但存在不确定性 关于最佳平台和保护相关性。减毒活疫苗可能会引发更广泛的 免疫反应的全部内容，但在安全性和免疫原性之间取得平衡具有挑战性。 此次持续合作的长期目标是利用豚鼠巨细胞病毒（GPCMV）模型 测试有关针对先天性感染的安全有效疫苗的最佳设计的假设。我们最近 发现包含一个五聚体复合物（PC），由 GPCMV gH、gL 和 GP129、131 和 133（HCMV PC 的同源物），能够产生一种可预防感染的活减毒疫苗 先天性 GPCMV 传播，但疫苗的毒性令人无法接受。在平行研究中我们观察到 对原型 GPCMV 毒株 22122 具有孕前免疫力的怀孕母鼠的病毒挑战 异源“临床分离株”CIDMTR 菌株导致母体再次感染和先天性 新挑战菌株的传播。这些发现以及 HCMV 感染者的临床观察结果 女性建议，疫苗可能需要比“自然免疫”表现更好，才能预防 再次感染。我们假设一个设计合理、PC 完整但禁用的传染性单循环 (DISC) 与 gB 亚基和 “自然”免疫力。在目标 1 中，我们通过比较 PC 阳性疫苗（通过 与 MF59 相比，GPCMV 编码的 MHC I 同源物和病毒蛋白激酶 R (PKR) evasin 的缺失 佐剂重组gB。我们将检查两次原发性孕产妇感染后的保护程度 以及在受异源菌株攻击后具有孕前免疫力的母鼠的再次感染 怀孕。我们将通过使用 PC-intact 开发 DISC 疫苗，进一步优化目标 2 中的 CMV 疫苗 具有与必需病毒蛋白融合的不稳定结构域的病毒。与临床试验中的 HCMV 疫苗相比， 我们假设 DISC 疫苗中的病毒复制被阻断在 DNA 复制下游 进展到晚期基因表达并产生更广泛的免疫原性蛋白质。目标 3 将评估 删除宿主细胞防御的病毒拮抗剂（例如蛋白激酶 R (PKR)）是否有助于疫苗开发 设计。我们将检验 GPCMV 编码第二个 PKR 拮抗剂的假设，消除该拮抗剂将 有望研制出安全有效的疫苗。此外，我们将在疫苗中过度表达 dsRNA 构建的目的是提高安全性和免疫原性。将评估疫苗的减毒效果 免疫原性和优化的疫苗将用于识别保护的免疫相关性，包括非 IgG 的中和功能。我们的研究将探索一个总体假设，即免疫力是由 CMV 疫苗可以优于“自然”孕前免疫，这是与 HCMV 疫苗高度相关的问题。