Importance of immune-cell lipid signaling in events leading to type 1 diabetes

免疫细胞脂质信号传导在导致 1 型糖尿病的事件中的重要性

• 批准号: 9807734
• 负责人: SASANKA RAMANADHAM
• 金额: $ 22.28万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-19 至 2021-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9807734
• 关键词: 12-HETE; Address; Adoptive Transfer; Arachidonic Acids; Autoimmune Process; B-Lymphocytes; Beta Cell; CD4 Positive T Lymphocytes; CD8-Positive T-Lymphocytes; Cell Death; Cell Separation; Cells; Cytotoxic T-Lymphocytes; Development; Diabetes Mellitus; Dinoprostone; Eicosanoids; Enzymes; Event; Fatty Acids; Generations; Goals; Immune; Immune response; Immunoblotting; Immunotherapy; Inbred NOD Mice; Incidence; Infiltration; Inflammatory; Insulin-Dependent Diabetes Mellitus; Islets of Langerhans; Knock-out; Lead; Leukotrienes; Lipids; Lysophospholipids; Membrane; Non obese; Phenotype; Phospholipase; Phospholipids; Play; Positioning Attribute; Prediabetes syndrome; Preparation; Process; Production; Protocols documentation; Reporting; Role; Sampling; Signal Transduction; Splenocyte; Stress; System; T-Lymphocyte; TNF gene; Testing; Tumor-infiltrating immune cells; Work; cell preparation; cytokine; diabetic; glucose tolerance; improved; inhibitor/antagonist; islet; macrophage; new therapeutic target; novel; oxidized lipid; preservation; prevent

Type 1 diabetes (T1D) is a consequence of autoimmune destruction of pancreatic islet β-cells and the underlying causes for this process are incompletely understood. Our work suggests novel lipid signaling provided by macrophages and CD4+ T-cells impacts T1D incidence. In particular, the relevant lipids appear to be generated by the Ca2+-independent phospholipase A2β (iPLA2β), which is expressed in immune cells. iPLA2β hydrolyzes membrane phospholipids at the sn-2 position to release a lysophospholipid and a fatty acid. When the fatty acid is arachidonic acid, it can be metabolized to generate bioactive oxidized lipids, or eicosanoids, many of which are pro-inflammatory. We find that (a) an iPLA2β-selective inhibitor, when administered to spontaneous diabetes-prone non-obese diabetic (NOD) mice preserves β-cell mass, reduces T1D incidence and insulitis, (b) iPLA2β activity promotes M1 macrophage pro-inflammatory phenotype and TNFα production from CD4+ T-cells, (c) macrophage production of select pro-inflammatory eicosanoids (PGE2, leukotrienes, 12-HETE, DHETs) is increased in NOD and reduced in macrophages with reduced iPLA2β (NOD.iPLA2β-/+), (d) T1D incidence is reduced in NOD.iPLA2β-/+, (e) adoptive transfer of NOD.iPLA2β-/- macrophages or splenocytes decreases T1D incidence and improves glucose tolerance. We hypothesize that iPLA2β-derived lipids (iDLs) produced by CD4+/CD8+ T-cells and macrophages play critical roles in T1D development and will address this under the following Aims: 1. Determine the contribution of CD4+/CD8+ T-cell-iDLs to T1D. We propose to utilize CD4+ and CD8+ T-cell preparations from WT and iPLA2β-deficient NOD to (a) determine the requirement of T-cell iDLs for diabetes induction, (b) quantitate T-cell lipid production and identify the iDLs, (c) assess the impact of these select iDLs on islet function and survival. 2. Determine the contribution of macrophage-iDLs to T1D. We propose to (a) utilize macrophage preparations from WT and iPLA2β-deficient NOD to determine the temporal requirement of macrophage iDLs on diabetes induction, (b) assess diabetes development in NOD with selective deficiency in macrophage iPLA2β, (c) determine the impact of select macrophage iDLs on islet function and survival. 3. Assess the impact of CD4+/CD8+ T-cell-or macrophage-derived iDLs on islet iPLA2β. Preliminary results suggest that iPLA2β is induced in stressed β-cells by NFκB, and PGE2 has been reported to induce NFκB. We will test the possibility that macrophage and/or CD4+/CD8+ T-cell iDLs induce β-cell iPLA2β, which would be expected to participate in maintaining and amplifying immune responses. We will utilize adoptive transfer, systems level lipidomics, conditional knockouts, immunoblotting, message, IF, and select inhibition of lipid-generating enzymes protocols to address these Aims. R21 Goals. Short-term. Identify and evaluate CD4+/CD8+ T-cell and macrophage iDLs critical for T1D development. Overarching. This could lead to strategies to target and prevent generation of those lipids or modify the responsible lipid-generating enzyme in immune cells, in the context of immunotherapy.

1型糖尿病（T1D）是胰岛自动免疫破坏的结果，并且该过程的基本原因是不完全理解的。我们的工作表明，巨噬细胞提供的新型脂质信号传导和CD4+ T细胞会影响T1D事件。特别是，相关的脂质似乎是由Ca2+非依赖性磷脂酶A2β（IPLA2β）产生的，该磷脂酶A2β（IPLA2β）在免疫核管中表达。 IPLA2β在SN-2位置水解膜磷脂，以释放溶血磷脂和脂肪酸。当脂肪酸是花生四烯酸时，可以将其代谢以产生生物活性氧化物脂质或类花生酸，其中许多是促炎的。 We find that (a) an iPLA2β-selective inhibitor, when administered to spontaneous diabetes-prone non-obese diabetic (NOD) mice preserves β-cell mass, reduces T1D incidence and insulitis, (b) iPLA2β activity promotes M1 macrophage pro-inflammatory phenotype and TNFα production from CD4+ T-cells, (c) macrophage production of精选的促炎性类固醇（PGE2，白细胞，12-HETE，DHET）在巨噬细胞中增加并减少IPLA2β（nod.ipla2β-/+），（d）T1D发病率降低了NOD.IPLA2β-/+，（e）nod.ipla2β-/+，（e）nod.iplanod.ipla2β-/epla2β-（e）降低T1D发病率并提高葡萄糖耐量。我们假设由CD4+/CD8+ T细胞和巨噬细胞产生的IPLA2β衍生的脂质（IDL）在T1D发育中起着至关重要的作用，并将在以下目的下解决这一点：1。确定CD4+/CD8+ T-Cell-IDLS对T1D的贡献。我们建议利用来自WT和IPLA2β缺陷的NOD的CD4+和CD8+ T细胞制剂，以（a）确定T-Cell IDLS对糖尿病诱导的需求，（b）定量T细胞脂质脂质产生并识别IDL，（c）评估这些选择IDL对ISLET功能的影响。 2。确定巨噬细胞idls对T1D的贡献。 We propose to (a) utilize macrophage preparations from WT and iPLA2β-deficient NOD to determine the temporary requirement of macrophage iDLs on diabetes induction, (b) assess diabetes development in NOD with Selective deficiency in macrophage iPLA2β, (c) determine the impact of select macrophage iDLs on islet function and survival. 3。评估CD4+/CD8+ T-cell-OR巨噬细胞衍生的IDL对IPLA2β的影响。初步结果表明，NFκB在应力的β细胞中诱导IPLA2β，据报道PGE2诱导NFκB。我们将测试巨噬细胞和/或CD4+/CD8+ T细胞IDLS诱导β细胞IPLA2β的可能性，这有望参与维持和放大免疫调查。我们将利用自适应转移，系统级脂肪态学，有条件的敲除，免疫印迹，消息，if，并选择抑制脂质生成酶方案的抑制来解决这些目标。 R21目标。短期。识别和评估CD4+/CD8+ T细胞和巨噬细胞IDLS对于T1D开发至关重要。总体。这可能会导致靶向和防止这些脂质产生或修改免疫疗法中负责任的脂质生成酶的策略。