Does Antibody-Dependent Intracellular Neutralization Limit HSV-1 Reactivation?

抗体依赖性细胞内中和是否会限制 HSV-1 重新激活？

基本信息

批准号：
10573477
负责人：
David A Leib
金额：
$ 20.5万
依托单位：
DARTMOUTH COLLEGE
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-11-10 至 2024-10-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10573477
关键词：
Affinity Agonist Antibodies Apoptosis Bacteria Binding Blindness Brain CD8-Positive T-Lymphocytes Cell Culture Techniques Cell Lineage Cell Nucleus Cell membrane Cell surface Cells Cellular Membrane Central Nervous System Common Cold Complement Complex Cytomegalovirus Cytoplasmic Granules Cytosol Data Electroporation Equilibrium Fc Receptor Ganglia Genetic Transcription Granzyme HIV Herpes Labialis Herpes Simplex Virus Vaccines Herpesvirus 1 Human Human Herpesvirus 2 Human Herpesvirus 4 Immune Immune system Immunity Immunoglobulin A Immunoglobulin G Immunoglobulin M In Situ In Vitro Induced pluripotent stem cell derived neurons Infection Life Cycle Stages Lymphocyte Lytic Mediating Membrane Fusion MicroRNAs Modeling Molecular Monitor Mucous Membrane Nervous System Nervous System Trauma Neurons Newborn Infant Organ Peripheral Nervous System Primary Infection Production Proteins Recrudescences Repression Resistance Role Route Shelter facility Simplexvirus Structure of trigeminal ganglion Surface Testing Transcript Translating Viral Viral Antigens Viral Genome Virus Virus Latency Virus Replication Virus Shedding antiviral immunity arm cytotoxic design endosome membrane experimental study human disease human model human pathogen immunological synapse in vitro Model in vivo inhibitor interest latency associated transcript lytic gene expression mouse model multicatalytic endopeptidase complex neuron loss neurotropic pathogen perforin prevent residence seropositive stressor tau Proteins therapeutic target weapons

项目摘要

Antibodies that do not promote the destruction of pathogens in situ or prevent their internalization into target cells through opsonization are nevertheless key factors in immunity against intracellular pathogens. An important mechanism by which such “non-neutralizing” antibodies (nNAbs) curtail certain infections has been illuminated by the recent discovery of antibody-dependent intracellular neutralization (ADIN). In ADIN, cytosolic nNAbs bound to pathogens are recognized by the intracellular high-affinity Fc receptor Trim21 and the complex is degraded by the proteasome. ADIN has been found capable of eradicating an enveloped virus. Given that enveloped viruses shed bound antibodies upon cell membrane fusion, the means by which nNAbs access the cytosol is puzzling. That nNAbs access the cytosol in vivo but not in vitro suggests that culture models lack a critical cell or factor for nNAb entry. Herpes simplex viruses (HSV)-1 and -2 initially replicate in a lytic manner at mucosal surfaces but then establish life- long residence within ganglion neurons of the peripheral nervous system. In neuronal nuclei the viral genome enters latency, a state of quiescence in which replication is repressed and lytic proteins are produced at near-undetectable levels. As mature neurons are non-renewable and unchecked viral replication can lead to central nervous system damage, the control of latency is critical to the host. Ganglia are monitored by CD8+ T-cells, which deliver granzyme B at the immunological synapse with infected neurons via perforin pores. Cytosolic granzyme B digests ICP4, an essential transcriptional regulator. The model is therefore that without ICP4 to upregulate transcript production, latency is perpetuated. Our data show that ICP4 antibodies exist in seropositive human trigeminal ganglia, suggestive of a check on ICP4 expression by granzyme B and possibly by antibodies to ICP4 that mediate its ADIN. We hypothesize that antibody-dependent intracellular neutralization of ICP4 limits HSV-1 reactivation. We will address this in experiments of two Specific Aims: 1) assess whether antibodies gain access to the neuronal cytosol through the close interaction between CD8+-T-cells and latently-infected neurons; and 2) determine whether non-neutralizing antibodies direct ADIN of ICP4 produced during latent neuronal infection, stifling viral reactivation. We will use convergent approaches to benefit from both an in vivo → ex vivo mouse model of human HSV-1 latency, and an in vitro model of latent HSV-1 infection in human induced pluripotent stem cell-derived neurons. If successful, Aim 1 will define a heretofore undescribed route of nNAb entry into cells in the context of HSV-1 latency. Aim 2 will elucidate the molecular basis of the complex balance between viral latency and host immunity. If successful, this R21 study will shift the focus of HSV vaccine target design to accommodate a role for ADIN in anti-viral immunity, and indicate potential therapeutic targets including inhibitors of reactivation, or agonists of ADIN. Advances from our studies could also inform far-reaching approaches to antagonize human pathogens with a latency state including HIV, HCMV, MeV, and EBV.

不会促进原位破坏病原体或阻止其内化到靶细胞中的抗体然而，通过调理作用是针对细胞内病原体免疫的一个重要机制。最近的研究表明，这种“非中和”抗体（nNAb）可以减少某些感染。抗体依赖性细胞内中和 (ADIN) 的发现在 ADIN 中，胞质 nNAb 与病原体结合。被细胞内高亲和力 Fc 受体 Trim21 识别，复合物被 ADIN 降解。已发现能够消灭有包膜病毒，因为病毒会在细胞上释放结合的抗体。膜融合，nNAb 进入细胞质的方式令人费解，nNAb 在体内却无法进入细胞质。体外实验表明培养模型缺乏 nNAb 进入的关键细胞或因子。单纯疱疹病毒 (HSV)-1 和 -2 最初以裂解方式在粘膜表面复制，但随后建立生命- 病毒基因组在周围神经系统的神经节神经元中长期驻留。潜伏期，一种静止状态，其中复制受到抑制，裂解蛋白的产生量几乎无法检测到。由于成熟的神经元是不可再生的，并且不受控制的病毒复制会导致中枢神经系统损伤，潜伏期的控制对于宿主来说至关重要，CD8+ T 细胞负责监测神经节，这些细胞在神经节处传递颗粒酶 B。免疫突触通过穿孔素孔与受感染的神经元相互作用，胞质颗粒酶 B 消化 ICP4，这是一种必需的物质。因此，该模型是如果没有 ICP4 上调转录产物，则潜伏期为我们的数据显示，血清阳性的人三叉神经节中存在 ICP4 抗体，提示需要进行检查。 ICP4 由颗粒酶 B 表达，也可能由介导其 ADIN 的 ICP4 抗体表达。我们追求抗体依赖性的 ICP4 细胞内中和限制 HSV-1 的重新激活。在两个具体目标的实验中解决这个问题：1）评估抗体是否通过 CD8+-T 细胞与潜伏感染神经元之间的密切相互作用；2) 确定是否具有非中和作用；抗体直接抑制潜伏神经元感染期间产生的 ICP4 的 ADIN，抑制病毒重新激活。方法从人类 HSV-1 潜伏期的体内→离体小鼠模型和体外模型中受益如果成功，目标 1 将定义人类诱导多能干细胞衍生神经元中的潜伏 HSV-1 感染。迄今为止，在 HSV-1 潜伏期中，nNAb 进入细胞的途径尚未描述，目标 2 将阐明其分子机制。病毒潜伏期和宿主免疫之间复杂平衡的基础如果成功，这项 R21 研究将转移焦点。 HSV 疫苗靶点设计适应 ADIN 在抗病毒免疫中的作用，并表明潜在的治疗方法我们研究的进展也可以为深远的影响提供信息。拮抗潜伏状态人类病原体的方法，包括 HIV、HCMV、MeV 和 EBV。