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Mechanisms of Cellular and Humoral Immune Evasion and Subsequent Polyomavirus Encephalitis

细胞和体液免疫逃避及随后的多瘤病毒脑炎的机制

基本信息

批准号：
9760815
负责人：
Heather Marie Ren
金额：
$ 2.54万
依托单位：
PENNSYLVANIA STATE UNIV HERSHEY MED CTR
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-01 至 2020-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9760815
关键词：
AIDS/HIV problem Acquired Immunodeficiency Syndrome Adaptive Immune System Allografting Amino Acids Animal Model Antibodies Antibody Affinity Antibody Repertoire Antibody Response Antibody Specificity Antiviral Agents Autoimmune Diseases Autoimmune Process B-Lymphocytes Biological Assay Blood Brain Brain Diseases CD4 Positive T Lymphocytes CD8-Positive T-Lymphocytes CD8B1 gene Capsid Proteins Cells Central Nervous System Diseases Central Nervous System Infections Chronic Complication Data Defect Development Disease Encephalitis Enzyme-Linked Immunosorbent Assay Epitopes Genomic DNA Goals HIV Haplotypes Hematologic Neoplasms Homeostasis Host Defense Humoral Immunities Immune Immune Evasion Immune response Immunocompromised Host Immunoglobulin G Immunohistochemistry Immunologic Monitoring Immunologics Immunosuppression Impairment Incidence Individual Infection Inflammatory Integrin alpha4 Interleukin-10 Interleukins JC Virus Label Laboratories Lesion Life Link Maintenance Mediating Memory Messenger RNA Modeling Monoclonal Antibodies Multiple Sclerosis Mus Mutant Strains Mice Mutation Neuraxis Neuroglia Pathogenesis Patients Plasma Cells Polyomavirus Polyomavirus Infections Prevention Preventive therapy Preventive treatment Production Progressive Multifocal Leukoencephalopathy Proteins Reaction Receptor Cell Receptor Signaling Residencies Role Serum Signal Transduction Source Specificity Structure of germinal center of lymph node Systemic Lupus Erythematosus T cell response T-Lymphocyte Testing Time Tissues Transplantation Tropism Tumor-infiltrating immune cells Variant Viral Virus Virus Diseases base central nervous system demyelinating disorder chemotherapy cytokine immunomodulatory therapies immunosuppressed improved interleukin-21 interleukin-21 receptor leukemia mouse model mouse polyomavirus multiple sclerosis patient mutant natalizumab neurotropic neurotropic virus neutralizing antibody prevent receptor residence response transcriptome transcriptome sequencing

项目摘要

ABSTRACT Progressive Multifocal Leukoencephalopathy (PML), a life-threatening demyelinating brain disease caused by JC polyomavirus (JCV), is a significant complication for patients with HIV/AIDS, hematologic malignancies, rheumatologic diseases, and those receiving long-term immunomodulating therapies. The immunomodulating therapy mostly closely associated with PML is natalizumab, an α4 integrin antibody (Ab) commonly used to treat multiple sclerosis (MS). Lack of a tractable animal model for PML is a widely recognized hurdle to defining the mechanisms of immunological control of JCV CNS infection. Using mouse polyomavirus (MuPyV), our laboratory developed a robust model of polyomavirus-associated demyelinating leukoencephalitis, with viral infection and T cell infiltration. This proposal seeks to use the MuPyV-CNS infection model to mechanistically understand the cellular and humoral immune mechanisms in place to control JCV CNS infection and how immunosuppression predisposes patients to JCV CNS infection. Increasing evidence supports the importance of CD4+ T cells in controlling JCV and thereby preventing PML. Recent studies in our laboratory show that CD4+ T cells are essential for differentiation and maintenance of MuPyV-specific tissue-resident memory CD8+ T cells (TRMs) in the brain. My preliminary data strongly supports the likelihood that IL-21 is a major component of the help provided by CD4+ T cells. I have further found that the serum from IL-21 receptor (IL21R)-deficient mice has a reduced ability to neutralize MuPyV carrying an amino acid mutation in its VP1 capsid protein that corresponds to a frequent VP1 mutation in PML-JCV. In Specific Aim 1, I hypothesize that IL-21 is required for brain-infiltrating CD8+ T cells to differentiate into TRMs. To test this hypothesis, I will define a time course for IL-21 production in the MuPyV-infected brain, its cellular sources, and when its receptor is expressed by MuPyV-specific CD8+ T cells. Using donor MuPyV-specific CD8+ T cells lacking IL21R, I will determine if signaling through the IL21R is intrinsically required by CD8+ T cells for their differentiation into TRMs. I will also apply RNA-seq to determine if the transcriptomes of IL21R-/- CD8+ T cells in the brain are similar to CD8+ T cells in CD4+ T cell-deficient mice. In Specific Aim 2, I hypothesize that IL21R signaling diversifies the VP1 Ab repertoire in a B cell-intrinsic manner to facilitate recognition of a MuPyV carrying a PML-synonymous VP1- mutation. To test this hypothesis, I will use MuPyV Ab neutralization assays, ELISAs, and germinal center immunohistochemistry to define the time course for developing a hole in the VP1 Ab specificity repertoire under T-independent (TCRα-/-) and IL-21-deficient (IL21R-/-) conditions. I also will determine plasma cell specificity against the PML-synonymous VP1 MuPyV mutant using fluorescently labeled MuPyVs in these aforementioned conditions. Finally, I will distinguish whether the mechanistic basis for the diminished VP1 neutralizing Ab repertoire is due to an intrinsic defect in IL21R signaling in B and/or T cells.

抽象的进行性多灶性白质脑病 (PML)，一种由以下疾病引起的危及生命的脱髓鞘性脑病 JC 多瘤病毒 (JCV) 是 HIV/AIDS、血液恶性肿瘤、风湿病以及接受长期免疫调节治疗的患者。免疫调节与 PML 密切相关的治疗方法是那他珠单抗，一种 α4 整联蛋白抗体 (Ab)，常用于治疗治疗多发性硬化症（MS）。缺乏易处理的 PML 动物模型是定义 PML 的一个广泛公认的障碍 JCV中枢神经系统感染的免疫控制机制。使用小鼠多瘤病毒 (MuPyV)，我们的实验室开发了多瘤病毒相关脱髓鞘性白质脑炎的稳健模型，其中病毒感染和T细胞浸润。该提案旨在利用 MuPyV-CNS 感染模型来机械地了解控制 JCV CNS 感染的细胞和体液免疫机制以及如何控制 JCV CNS 感染免疫抑制使患者易受 JCV CNS 感染。越来越多的证据支持重要性 CD4+ T 细胞控制 JCV 从而预防 PML。我们实验室最近的研究表明 CD4+ T 细胞对于 MuPyV 特异性组织驻留记忆 CD8+ 的分化和维持至关重要大脑中的 T 细胞 (TRM)。我的初步数据强烈支持 IL-21 是主要成分的可能性 CD4+ T 细胞提供的帮助。我进一步发现，IL-21受体（IL21R）缺陷的血清小鼠中和 MuPyV 的能力降低，该 MuPyV 的 VP1 衣壳蛋白中携带氨基酸突变，导致对应于 PML-JCV 中常见的 VP1 突变。在具体目标 1 中，我假设需要 IL-21 用于脑浸润 CD8+ T 细胞分化为 TRM。为了检验这个假设，我将定义一个时间过程 MuPyV 感染大脑中 IL-21 的产生、其细胞来源以及其受体何时表达 MuPyV 特异性 CD8+ T 细胞。使用缺乏 IL21R 的供体 MuPyV 特异性 CD8+ T 细胞，我将确定是否 CD8+ T 细胞分化为 TRM 本质上需要通过 IL21R 发出信号。我也会应用 RNA-seq 确定大脑中 IL21R-/- CD8+ T 细胞的转录组是否与 CD8+ T 相似 CD4+ T 细胞缺陷小鼠体内的细胞。在具体目标 2 中，我假设 IL21R 信号传导使 VP1 Ab 多样化以 B 细胞固有的方式来促进识别携带 PML 同义 VP1- 的 MuPyV 突变。为了检验这个假设，我将使用 MuPyV Ab 中和测定、ELISA 和生发中心免疫组织化学确定 VP1 Ab 特异性库中出现空洞的时间过程在 T 独立 (TCRα-/-) 和 IL-21 缺乏 (IL21R-/-) 条件下。我还将确定浆细胞使用荧光标记的 MuPyV 在这些中针对 PML 同义 VP1 MuPyV 突变体的特异性上述条件。最后，我将区分VP1减少的机制基础是否中和抗体库是由于 B 细胞和/或 T 细胞中 IL21R 信号传导的内在缺陷所致。