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 β 细胞自身免疫性破坏的结果，这一过程的根本原因尚不完全清楚。我们的工作表明巨噬细胞和 CD4+ T 细胞提供的新型脂质信号传导会影响 T1D 的发病率。特别是，相关脂质似乎是由不依赖 Ca2+ 的磷脂酶 A2β (iPLA2β) 产生的，该酶在免疫细胞中表达。 iPLA2β 在 sn-2 位点水解膜磷脂，释放溶血磷脂和脂肪酸。当脂肪酸是花生四烯酸时，它可以代谢产生具有生物活性的氧化脂质或类二十烷酸，其中许多具有促炎作用。我们发现，(a) iPLA2β 选择性抑制剂，当给予易患自发性糖尿病的非肥胖糖尿病 (NOD) 小鼠时，可以保留 β 细胞质量，减少 T1D 发病率和胰岛素炎，(b) iPLA2β 活性促进 M1 巨噬细胞促炎表型和 CD4+ T 细胞产生 TNFα，(c) 巨噬细胞产生 选择促炎类花生酸（PGE2、白三烯、12-HETE、DHET）在 NOD 中增加，在巨噬细胞中减少，同时 iPLA2β 减少 (NOD.iPLA2β-/+)，(d) NOD.iPLA2β-/+ 中 T1D 发病率降低，(e) NOD.iPLA2β-/- 巨噬细胞或脾细胞的过继转移 降低 T1D 发病率并提高葡萄糖耐量。我们假设 CD4+/CD8+ T 细胞和巨噬细胞产生的 iPLA2β 衍生脂质 (iDL) 在 T1D 发展中发挥关键作用，并将在以下目标下解决这一问题： 1. 确定 CD4+/CD8+ T 细胞-iDL 对 T1D 的贡献。我们建议利用来自 WT 和 iPLA2β 缺陷型 NOD 的 CD4+ 和 CD8+ T 细胞制剂来 (a) 确定 T 细胞 iDL 对糖尿病诱导的需求，(b) 定量 T 细胞脂质产生并鉴定 iDL，(c) 评估这些选定的 iDL 对胰岛功能和存活的影响。 2. 确定巨噬细胞-iDL 对 T1D 的贡献。我们建议（a）利用WT和iPLA2β缺陷型NOD的巨噬细胞制剂来确定巨噬细胞iDL对糖尿病诱导的时间需求，（b）评估巨噬细胞iPLA2β选择性缺陷的NOD中糖尿病的发展，（c）确定选定的巨噬细胞iDL对胰岛功能和存活的影响。 3. 评估 CD4+/CD8+ T 细胞或巨噬细胞衍生的 iDL 对胰岛 iPLA2β 的影响。初步结果表明，NFκB 在应激的 β 细胞中诱导 iPLA2β，并且据报道 PGE2 可以诱导 NFκB。我们将测试巨噬细胞和/或 CD4+/CD8+ T 细胞 iDL 诱导 β 细胞 iPLA2β 的可能性，预计它将参与维持和放大免疫反应。我们将利用过继转移、系统级脂质组学、条件敲除、免疫印迹、消息、IF 和选择脂质生成酶抑制方案来实现这些目标。 R21 目标。短期的。识别并评估对 T1D 发展至关重要的 CD4+/CD8+ T 细胞和巨噬细胞 iDL。首要的。在免疫治疗的背景下，这可能会导致针对和防止这些脂质的生成或修改免疫细胞中负责的脂质生成酶的策略。