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Regulation of Innate Immune Signaling by Lyn Kinase

Lyn 激酶对先天免疫信号的调节

基本信息

批准号：
8870727
负责人：
Clifford A Lowell
金额：
$ 39.57万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-02-01 至 2020-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8870727
关键词：
Address Affect Allergic Animal Testing Animals Anti-Bacterial Agents Anti-Inflammatory Agents Anti-inflammatory Antibody Formation Area Autoimmune Diseases Autoimmune Process Autoimmunity B-Lymphocytes BCL10 gene Biochemical Biochemical Genetics C Type Lectin Receptors C-Type Lectins Cells Collaborations Complex Data Defect Dendritic Cells Development Diabetes Mellitus Disease Enzymes Functional disorder Generations Genetic Goals Hematopoietic Human Hyperactive behavior ITGAX gene Immune Immune Cell Activation Immune Complex Glomerulonephritis Immune Tolerance Immune response Immunity Immunoglobulin G Immunoglobulin M In Vitro Infection Inflammation Inflammatory Interleukin-1 Intestines Investigation Knock-out Lead Lupus Lymphocyte Lymphocyte Subset Lymphoid Mediating Methods Modeling Molecular Mouse Strains Mus Mutant Strains Mice Mutation Myeloid Cells Onset of illness Organism Pathogenesis Pathway interactions Patients Permeability Phenotype Phosphotransferases Play Process Production Protein Tyrosine Kinase Protein Tyrosine Phosphatase Proteins Recruitment Activity Regulation Relative (related person)Role Series Signal Pathway Signal Transduction Stromal Cells Supplementation T-Lymphocyte Testing Therapeutic Trials Tissues Work cell type chemical genetics cytokine disease phenotype genetic approach gut microbiota lupus-like lymph nodes microbiome mortality mouse model mutant novel protein complex public health relevance receptor research study therapeutic target

项目摘要

DESCRIPTION (provided by applicant): There is a growing recognition that innate immune cells play a critical role in initiating and sustaining autoimmune and inflammatory disorders. The Lyn tyrosine kinase is one of the primary inhibitory enzymes that regulate innate immune cell signaling. Lyn functions by phosphorylating inhibitory receptors that recruit tyrosine phosphatases to down modulate cellular activation. In the absence of Lyn kinase, mice develop spontaneous autoimmunity resembling human systemic lupus erythematous (SLE). In preliminary studies, we have found that loss of Lyn kinase in dendritic cells (DCs) alone is sufficient to cause a severe autoimmune/inflammatory disease, with strong tissue inflammation and reduced survival, compared to the global lyn-/- mice. This disease is completely dependent on MyD88-signaling, since generation of mice lacking MyD88 and Lyn in DCs alone lack the inflammation and autoimmunity. These observations provide a clear example that mutations resulting in loss of inhibitory signaling in DCs can result in breakdown of immune tolerance in lymphocytes, leading to autoimmunity. This proposal consists of 4 specific aims. Our first aim is to define the molecular mechanisms by which inhibition of tyrosine kinase pathways impacts MyD88 signaling in DCs. We hypothesize that the cross talk between these pathways occurs via the CARD9/Malt1/Bcl10 complex, which we will investigate biochemically and genetically. We will use a chemical genetic approach to define the molecular substrates of Lyn in DCs. Aim #2 will expand on our preliminary observations, done with Dr. Lynch (UCSF) that loss of Lyn in DCs results in dysbiosis of gut microbiota, allowing for outgrowth of species that may drive systemic inflammation by altering the intestinal barrier function. We will expand on these observations in a series of microbiota profiling experiments, by use of bacterial supplementation methods, and by directly examining intestinal barrier function in the various Lyn-deficient strains. Aim #3 will expand on preliminary data suggesting that an undefined Lyn-mediated signaling pathway in non- hematopoietic cells may have an immunomodulatory effect on the disease process in lyn-/- mice. Lyn related inhibitory signaling in non-hematopoietic cells is very poorly studied. We will focus on follicular retricular cells using biochemical and genetic means (including generating mutant mice lacking Lyn in these cells specifically). Aim #4 will expand on preliminary studies done with Dr. Locksley (UCSF) showing that group 2 innate lymphocytes (ILC2s) are expanded and activated in lyn-/- mice. This aim will address whether altered signaling in ILC2 cells alone can lead to spontaneous disease phenotypes (by generating novel ILC2-specific lyn mutants) and whether these cells may contribute to autoimmune disease. Since changes in Lyn kinase related signaling pathways have been observed in human SLE patients and Lyn is now a therapeutic target in diabetes treatments (therapeutic trials) understanding the inhibitory signaling pathways regulated by this kinase in innate cells will have direct impact on human autoimmune and inflammatory conditions.

描述（由申请人提供）：人们越来越认识到先天免疫细胞在引发和维持自身免疫和炎症性疾病中发挥着关键作用。 Lyn 酪氨酸激酶是调节先天免疫细胞信号传导的主要抑制酶之一。 Lyn 通过磷酸化抑制性受体发挥作用，这些受体招募酪氨酸磷酸酶来下调细胞激活。在缺乏 Lyn 激酶的情况下，小鼠会产生类似于人类系统性红斑狼疮 (SLE) 的自发自身免疫。在初步研究中，我们发现与全球lyn-/-小鼠相比，仅树突状细胞（DC）中Lyn激酶的缺失就足以引起严重的自身免疫/炎症性疾病，伴有强烈的组织炎症和存活率降低。这种疾病完全依赖于 MyD88 信号传导，因为仅在 DC 中缺乏 MyD88 和 Lyn 的小鼠一代缺乏炎症和自身免疫。这些观察结果提供了一个明确的例子，即导致树突状细胞中抑制信号传导丧失的突变可能会导致淋巴细胞免疫耐受性的破坏，从而导致自身免疫。该提案包含 4 个具体目标。我们的首要目标是确定抑制酪氨酸激酶通路影响 DC 中 MyD88 信号传导的分子机制。我们假设这些途径之间的串扰通过 CARD9/Malt1/Bcl10 复合体发生，我们将从生化和遗传学方面进行研究。我们将使用化学遗传学方法来定义 DC 中 Lyn 的分子底物。目标 #2 将扩展我们与 Lynch 博士 (UCSF) 一起完成的初步观察结果，即 DC 中 Lyn 的缺失会导致肠道微生物群失调，从而导致可能通过改变肠道屏障功能而驱动全身炎症的物种的生长。我们将通过使用细菌补充方法并直接检查各种 Lyn 缺陷菌株的肠道屏障功能，在一系列微生物群分析实验中扩展这些观察结果。目标 #3 将初步数据表明，非造血细胞中未定义的 Lyn 介导的信号通路可能对 lyn-/- 小鼠的疾病过程具有免疫调节作用。非造血细胞中 Lyn 相关抑制信号传导的研究非常少。我们将重点利用生化和遗传手段研究滤泡网状细胞（包括产生这些细胞中专门缺乏 Lyn 的突变小鼠）。目标 #4 将扩展 Locksley 博士 (UCSF) 所做的初步研究，该研究显示第 2 组先天淋巴细胞 (ILC2) 在 lyn-/- 小鼠中扩增并激活。这一目标将解决仅改变 ILC2 细胞信号传导是否会导致自发疾病表型（通过产生新型 ILC2 特异性 lyn 突变体）以及这些细胞是否可能导致自身免疫性疾病。由于在人类 SLE 患者中观察到 Lyn 激酶相关信号通路的变化，并且 Lyn 现在是糖尿病治疗（治疗试验）的治疗靶点，了解先天细胞中由该激酶调节的抑制性信号通路将对人类自身免疫和炎症状况产生直接影响。