Pathogenic consequences of B cell-mediated CD4 T cell activation in a MHCII-dependent model of central nervous system autoimmunity

MHCII 依赖性中枢神经系统自身免疫模型中 B 细胞介导的 CD4 T 细胞激活的致病后果

• 批准号: 9230220
• 负责人: Chelsea Renee Parker Harp
• 金额: $ 3.07万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-02-15 至 2018-08-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9230220
• 关键词: Address; Adoptive Transfer; Animal Model; Animals; Anti-Inflammatory Agents; Anti-inflammatory; Antibodies; Antigen Presentation; Antigen Targeting; Antigen-Presenting Cells; Antigens; Autoimmune Diseases; Autoimmunity; B-Lymphocytes; Binding; Biological Assay; Blood; Blood - brain barrier anatomy; Brain; CD4 Positive T Lymphocytes; CNS autoimmunity; Cell Communication; Cell Lineage; Cell Shape; Cell physiology; Central Nervous System Diseases; Cerebrospinal Fluid; Chronic; Clinical; Confocal Microscopy; Demyelinations; Dendritic Cells; Development; Disease; Effector Cell; Etiology; Exhibits; Experimental Autoimmune Encephalomyelitis; Flow Cytometry; Frequencies; Generations; Health; Human; Immunization; Immunoglobulins; Immunotherapy; In Vitro; Inflammatory; Interleukin-1 beta; Interleukin-6; Learning; Lesion; Location; MS4A1 gene; Mediating; Membrane; Modeling; Molecular Profiling; Multiple Sclerosis; Mus; Neuraxis; Oligoclonal Bands; Organ; Pathogenesis; Pathogenicity; Peripheral; Plasma Cells; Play; Predisposition; Production; Quantitative Reverse Transcriptase PCR; Receptors, Antigen, B-Cell; Relapse; Research; Role; Shapes; Specificity; Splenocyte; Study Subject; System; T cell response; T-Lymphocyte; TNF gene; Testing; Tissues; Tumor Necrosis Factor-Beta; autoreactive T cell; axon injury; central nervous system demyelinating disorder; cytokine; effective therapy; experimental study; human disease; immunoregulation; in vivo; in vivo Model; interest; laboratory experiment; mouse model; multiple sclerosis patient; multiple sclerosis treatment; neuroinflammation; novel; oligodendrocyte-myelin glycoprotein; public health relevance; response; targeted treatment; trafficking; treatment trial

 DESCRIPTION (provided by applicant): Multiple sclerosis (MS) is a neuro-inflammatory disease of the central nervous system (CNS) that causes demyelination and axonal damage. Current therapies available to MS patients are sub-optimal, and there is no cure for this chronic, debilitating disease. B cell depletion therapies have shown promise in several treatment trials, yet B cells can also play protective and anti-inflammatory roles that are important during health and disease. Determining the mechanisms by which B cell antigen presentation mediates neuroinflammation and tolerance in MS is crucial for developing immunomodulatory therapies targeted to encephalitogenic B cell functions. Using an in vivo conditional MHCII expression system and experimental autoimmune encephalomyelitis (EAE), our lab has demonstrated that B cells are not sufficient antigen presenting cells (APCs) for passive EAE induced by adoptive transfer of encephalitogenic CD4 T cells unless enough B cells recognize the cognate antigen, myelin oligodendrocyte glycoprotein (MOG). Further experiments have supported our hypothesis that MOG-specific, membrane bound B cell receptor, rather than MOG-specific secreted immunoglobulin, is critical to the propagation of CD4 T cell auto-reactivity, likely for efficient capture of target antigen. These findings highlight the importance of soluble antibody independent B cell functions to MS pathogenesis. In Aim 1 I will determine restrictions on the location of B cell antigen presentation by quantifying B cell localization and MHCII expression in the CNS compartment. I will also assay murine cerebrospinal fluid for the presence of intrathecal immunoglobulin indicative of B:T cell cognate interactions within the CNS. Lastly, the capacities of non-specific and antigen-specific B cells from passive EAE mice to traverse an in vitro blood brain barrier model will be tested. In Aim 2 I will define the effect of antigen-specifc B cells on CD4 T cell lineage fate during EAE. T cell cytokine production will be determined in antigen recall assays using naïve and in vitro- primed splenocytes from WT mice and mice with conditional expression in various APC subsets. Additionally, I will define the cytokine expression profile of B cells from different B-cell dependent EAE models and quantify B cell expression of IL-1β. The hypothesis that B cells shape T cell lineage plasticity will be tested by modulating th timing of B cell antigen presentation in passive EAE in conjunction with dendritic cell MHCII expression. Successful completion of the research proposed in these aims will increase our understanding of cellular mechanisms of inflammatory demyelinating diseases of the CNS. We will identify where important pathogenic functions of B cells occur in EAE and distinguish mechanisms of pathogenic cytokine generation as potential targets for immunotherapy in MS.

 描述（由申请人提供）：多发性硬化症 (MS) 是一种中枢神经系统 (CNS) 的神经炎症性疾病，可导致脱髓鞘和轴突损伤，目前可用于 MS 患者的治疗方法效果欠佳，并且无法治愈。这种慢性、使人衰弱的疾病在多项治疗试验中已显示出前景，但 B 细胞还可以发挥保护和抗炎作用，这在健康和疾病期间发挥着重要作用。递呈介导多发性硬化症的神经炎症和耐受性对于开发针对致脑炎 B 细胞功能的免疫调节疗法至关重要。我们的实验室利用体内条件性 MHCII 表达系统和实验性自身免疫性脑脊髓炎 (EAE) 证明，B 细胞并不是足够的抗原递呈细胞。 APC）用于由致脑炎 CD4 T 细胞过继转移诱导的被动 EAE，除非有足够的 B 细胞识别同源抗原髓磷脂少突胶质细胞糖蛋白(MOG)。进一步的实验支持了我们的假设，即 MOG 特异性膜结合 B 细胞受体，而不是 MOG 特异性分泌的免疫球蛋白，对于 CD4 T 细胞自身反应性的传播至关重要，可能有助于有效捕获靶抗原。这些发现强调了可溶性抗体独立的 B 细胞功能对 MS 发病机制的重要性。在目标 1 中，我将通过量化 CNS 区室中的 B 细胞定位和 MHCII 表达来确定对 B 细胞抗原呈递位置的限制。小鼠脑脊液中是否存在鞘内免疫球蛋白，表明 CNS 内 B:T 细胞同源相互作用。最后，来自被动 EAE 小鼠的非特异性和抗原特异性 B 细胞穿过体外血脑屏障模型的能力将被确定。在目标 2 中，我将定义 EAE 过程中抗原特异性 B 细胞对 CD4 T 细胞谱系命运的影响，这将在抗原回忆测定中确定。此外，我将定义来自不同 B 细胞依赖性 EAE 模型的 B 细胞的细胞因子表达谱，并量化 IL-1β 的 B 细胞表达。将通过调节树突状细胞 MHCII 表达中被动 EAE 中 B 细胞抗原呈递的时间来测试 B 细胞塑造 T 细胞谱系的可塑性，这些目标中提出的研究的成功完成将增加我们对细胞机制的理解。我们将确定 EAE 中 B 细胞的重要致病功能发生的位置，并区分致病细胞因子的生成机制，作为 MS 免疫治疗的潜在靶点。