Btk breaks the tolerance of marginal zone macrophages to apoptotic antigens

Btk打破了边缘区巨噬细胞对凋亡抗原的耐受性

• 批准号: 8629254
• 负责人: John D Mountz
• 金额: --
• 依托单位: BIRMINGHAM VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2017-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8629254
• 关键词: Activities of Daily Living; Agammaglobulinaemia tyrosine kinase; Anatomy; Antigen-Antibody Complex; Antigens; Apoptotic; Area; Arts; Autoantibodies; Autoimmune Diseases; Autoimmune Process; Autoimmunity; B-Lymphocytes; Biochemical; Biological Markers; Biology; Blood Circulation; Cells; Clinical; Data; Defect; Detection; Development; Dimensions; Dioxygenases; Disease; Early Diagnosis; Ensure; Event; Experimental Models; Flow Cytometry; Functional disorder; Gene Targeting; Genes; Human; Human Characteristics; Hyperactive behavior; Image; Immune; Immune System Diseases; Immunoglobulin G; Individual; Inflammatory; Interferon Type I; Interferons; Interleukin-10; Interleukin-6; Knowledge; Lead; Link; Liposomes; Lupus; Mediating; Modeling; Molecular; Mus; Onset of illness; Pathogenesis; Pathway interactions; Patients; Pharmaceutical Preparations; Phase; Phenotype; Play; Positioning Attribute; Prevention; Process; Production; Recruitment Activity; Research; Resources; Role; Signal Transduction; Spleen; Staging; Structure; Systemic Lupus Erythematosus; T-Lymphocyte; Techniques; Technology; Testing; Therapeutic; Therapeutic Intervention; Time; Tissues; Tyrosine Kinase Inhibitor; Work; base; effective intervention; gene therapy; immunogenic; in vivo; indoleamine; innovation; insight; loss of function; macrophage; mouse model; nanoscience; novel; novel therapeutic intervention; pre-clinical; prevent; public health relevance; response; small hairpin RNA; success; therapeutic target; vector

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease in which autoantibodies (autoAbs) play a key role in eliciting tissue destruction. Multiple immune irregularities have been identified, including hyperactivity of T and B cells, in patients with SLE but its pathogenesis remains an enigma. This gap in knowledge is a significant impediment to timely diagnosis, early therapeutic intervention and potential prevention. We propose a highly innovative pathogenic model that links irregularities typical of patients with SLE including the presence of autoAbs several years prior to manifestation of clinical disease, the presence of large immune complexes (ICs) and autoAbs targeting apoptotic debris in the circulation, the production of higher levels of type I interferons (IFNs) and their target genes, and the hyperactivity of B and T cells. The central component of the proposed hypothetical model is that the tolerogenic capacity of marginal zone macrophages (MZMs) in the marginal zone (MZ) of the spleen plays a pivotal role in the progression of SLE. We propose that there is a gradual erosion of the normally large reserve in the tolerogenic capacity of the MZMs during the pre-clinical disease phase of SLE. When the tolerogenic capacity of the MZMs declines below a critical threshold, the individual becomes susceptible to inciting events, especially those that induce type I IFNs, that precipitate a further rapid loss of tolerogenic capacity resulting in production of high titers of pathogenic autoAbs and clinical disease. We further propose that the erosion of the tolerogenic capacity of the MZMs during the pre-clinical state is driven primarily by circulating apoptotic cell antigens (AC-Ags) and IgG ICs that enhance immunogenic signals which in combination with type I IFN pathways reduce the tolerogenic capacity of MZMs. At the molecular level, we propose that the loss of the tolerogenic capacity of the MZMs is associated with an increase in expression of Bruton tyrosine kinase (Btk) in MZMs in response to AC-Ag/ICs. As the expression of Btk is further increased, the MZMs will relocate from their anatomic position adjacent to the FO and locate to more remote areas of the MZ. Some individuals develop ICs that increase type I IFN signaling and Btk induction in MZMs to the point that a threshold is reached at which a pro-inflammatory "trigger" precipitates the onset of clinical disease. ¿ Aim 1 will determine if autoAb-ICs induction of Btk leads to MZM dysfunction and loss. ¿ Aim 2 will determine if IFN¿ and ICs work together to break MZM tolerance. ¿ Aim 3 will determine if elevation of pBtk leads to loss of MZ macrophages, development of inflammatory macrophages and elevation of type I IFN genes in SLE patients. The proposed work will use state-of-art confocal imaging and high dimension phospho-flow cytometry analyses to enable detection of the aberrant signaling events associated with loss of function and numbers of MZMs due to abnormally upregulated pBtk in both humans and mice. We will also apply B cell tetramer technology to enable tracking the development of pathogenic multireactive autoAb forming B cells associated with the decline of MZM numbers and tolerance function. Btk activity will be manipulated by systemic treatment of mice with an irreversible Btk inhibitor, PCI-32765 or liposome gene therapy to directly target Btk shRNA or PCI-32765 to MZMs. Significance: This hypothetical model, if proven true, would pinpoint a defining event in the transition from pre-clinical to clinical SLE, which would suggest a biomarker that could be used in earlier diagnosis of SLE, i.e., the numbers and Btk phenotype of the MZMs in experimental models of autoimmunity, and the Btk phenotype of PBMCs from patients. This would have major implications in terms of earlier and thus more effective intervention using currently available therapeutic strategies. In addition, the results will provide insights critical to the development of Btk as a potential therapeutic target in SLE.

全身性红斑狼疮（SLE）是一种多因素自身免疫性疾病，自身抗体 （自动）在引起组织破坏中起关键作用。已经确定了多种免疫不规则性， 包括T和B细胞的多动症，在患有SLE的患者中，但其发病机理仍然是一个谜。 知识差距是及时诊断，早期热干预和 潜在的预防。我们提出了一个高度创新的致病模型，该模型将典型的不规则性联系起来 SLE的患者包括在临床表现前几年的自动abs的患者 疾病，存在针对凋亡碎片的大型免疫复合物（IC）和自动动 循环，I型干扰素（IFN）及其靶基因的较高水平的产生，以及 B和T细胞的多动症。提出的假设模型的核心部分是 边缘区域（MZ）的边缘区巨噬细胞（MZM）的耐受能力（MZ） 在SLE的进展中起关键作用。我们提出，正常大的级别侵蚀 在SLE的临床前疾病阶段，MZM的耐受能力储备。什么时候 MZMS的耐受能力下降以下，个人变得易感性 煽动事件，尤其是那些影响I型IFN的事件，这种宝贵的事件进一步迅速损失 耐受能力，导致致病性自动ab和临床疾病的高滴度产生。我们 进一步的建议，即在临床前状态下MZM的耐受能力的侵蚀是 由循环凋亡细胞抗原（AC-AGS）和IgG IC驱动的，可增强免疫原性 与I型IFN途径结合使用的信号降低了MZM的耐受能力。 在分子水平上，我们提出MZM的耐受能力的丧失是相关的 随着AC-AG/IC的响应，MZM中Bruton酪氨酸激酶（BTK）的表达增加。作为 BTK的表达进一步增加，MZMS将从其解剖位置搬迁到 FO并定位到MZ的更偏远的区域。有些人会开发出增加I型IFN的IC MZM中的信号传导和BTK诱导，以达到促炎的阈值 “触发”会引起临床疾病的发作。 AIM 1将确定BTK的自动启动诱导是否导致MZM功能障碍和损失。 AIM 2将确定IFN¿和IC是否共同努力打破MZM的耐受性。 �AIM3将确定PBTK的升高是否导致MZ巨噬细胞的损失，发展 SLE患者的I型IFN基因的炎症巨噬细胞和升高。 拟议的工作将使用最先进的共聚焦成像和高尺寸磷酸流细胞仪 分析以检测与功能丧失和功能丧失相关的异常信号事件 人类和小鼠绝对更新的PBTK引起的MZM数量。我们还将申请b 细胞四聚体技术能够跟踪致病性多反应性自动ab形成b的发展 与MZM数量下降和公差功能相关的细胞。 BTK活动将被操纵 通过全身治疗不可逆的BTK抑制剂，PCI-32765或脂质体基因治疗的小鼠 将BTK shRNA或PCI-32765直接靶向MZM。 意义：这种假设模型（如果被证明为真实）将在过渡中查明一个定义事件 从临床前到临床SLE，这表明可以在早期诊断中使用的生物标志物 SLE，即自身免疫模型中MZM的数字和BTK表型， 来自患者的PBMC的BTK表型。这将在早期和 因此，使用当前可用的治疗策略更有效的干预。此外，结果将 提供对BTK作为SLE的潜在治疗靶点至关重要的见解。