Innate-Adaptive Immune Interface in Liver Ischemia-Reperfusion Injury

项目一--摘要/摘要 缺血再灌注损伤(IRI)仍是限制原位肝移植成功的主要障碍 终末期肝病患者和肝源性肿瘤患者的移植(OLT)。我们的 该小组率先提出了肝脏IRI需要激活的CD4+T细胞来促进肝脏组织的概念 损坏。T细胞免疫球蛋白-3(Tim-3，由Havcr2基因编码)是T细胞的中枢负性调节因子 激活。CEACAM1(癌胚抗原相关细胞黏附分子1，由CC1基因编码) 已被确定为决定TIM-3功能的新的细胞配体。首先，我们发现，与 CEACAM1熟练(WT)肝、CEACAM1零突变(CC1-/-)加重了原位肝移植的IRI。第二，我们 研究发现，受体CD4+TIM-3+信号在IR应激原位肝移植(WT→TIM-3TG)中的益处是 当CEACAM1KO小鼠作为器官捐赠者(CC1-/-→TIM-3TG)时，完全消失。这些初步数据 1/Tim-3-CEACAM1负性调控对控制IRI至关重要。 在供体肝脏中对OLT浸润性CD4+T细胞和2/CEACAM1施加力竭样功能障碍 促进肝脏保护。项目I将通过两个相互关联的具体目标来检验这一假设： 目的1：探讨TIM-3-CEACAM1对IR应激性异体肝移植T细胞负调控的作用机制。一组 我们可以用于AIM 1实验的小鼠包括CD4+T细胞突变，它们是：I/CEACAM1Tg；II/Double TIM-3TG和CEACAM1-/-，以及：III/TIM-3TG和TIM-3-/-小鼠。 目标1.1。假设：宿主循环中CD4+T细胞上的CEACAM1-TIM-3信号促进疲劳- IRI-OLT的表型。 目标1.2。假设：在主导的CAECAM1信号下，Tim-3+CD4+耗尽的T细胞抑制 原位肝移植中IRI的发展和进展。 目的2：明确供体肝细胞CEACAM1调节异体原位肝移植IRI的机制。基因- AIM 2研究的目标菌株包括：I/肝脏CEACAM1失活(功能丧失；L-CC1-/-)；或II/ 强迫肝脏CEACAM1过度表达(功能获得；L-CC1Tg)。 目标2.1。假设：肝细胞特异性CEACAM1-β-连环蛋白再生功能增强 有助于保护肝脏。 目标2.2。假设：TIM-3-CECACAM1信号增强肝细胞自噬程序。 与PPG集成：通过提供对TIM-3-CEACAM1检查点监管的新见解 IR应激iso-OLT中的天然-适应性免疫界面，项目I自然告知/先于研究 评估宿主排斥反应如何调节allo-OLT的先天免疫激活/IRI后遗症(项目II)。直接 在小鼠原位肝移植模型中应用钝化炎症和促进保肝的方法将 加速评估人类肝移植的免疫表型(项目III)。

PROJECT I - SUMMARY/ABSTRACT Ischemia-reperfusion injury (IRI) remains the primary obstacle limiting the success of orthotopic liver transplantation (OLT) in patients with end-stage liver disease and those with tumors of hepatic origin. Our group has pioneered the concept that hepatic IRI requires activated CD4+ T cells to facilitate liver tissue damage. T cell immunoglobulin-3 (TIM-3; encoded by Havcr2 gene) is the central negative regulator of T cell activation. CEACAM1 (carcinoembryonic antigen-related cell adhesion molecule 1; encoded by CC1 gene) has been identified as a new cellular ligand determining TIM-3 function. First, we found that compared with CEACAM1 proficient (WT) livers, CEACAM1 null-mutation (CC1-/-) exacerbated IRI in OLT. Second, we discovered that the benefit of recipient CD4+TIM-3+ signaling in IR-stressed OLT (WT→TIM-3Tg) was completely lost when CEACAM1 KO mice served as organ donors (CC1-/-→TIM-3Tg). These preliminary data have led us to central hypothesis that 1/ TIM-3 – CEACAM1 negative regulation is essential to control IRI by imposing exhaustion-like dysfunction in OLT-infiltrating CD4+ T cells; and 2/ CEACAM1 in the donor liver promotes hepatoprotection. Project I will test this hypothesis through two interlocked specific aims: Aim 1: Define mechanisms of TIM-3 – CEACAM1 negative T cell regulation in IR-stressed iso-OLT. A panel of mice available to us for Aim 1 experiments include CD4+ T cell mutants, which are: i/ CEACAM1Tg; ii/ double TIM-3Tg and CEACAM1-/-; as well as: iii/ TIM-3Tg and TIM-3-/- mice. Aim 1.1. Hypothesis: CEACAM1 - TIM-3 signaling on host circulating CD4+ T cells promotes exhaustion- type phenotype in IRI–OLT. Aim 1.2. Hypothesis: Under dominant CAECAM1 signaling, TIM-3+CD4+ exhausted T cells inhibit the development and progression of IRI in OLT. Aim 2: Define mechanisms by which hepatocellular CEACAM1 in donor liver regulates IRI in iso-OLT. Gene- targeted strains for Aim 2 studies include: i/ hepatic CEACAM1 inactivation (loss-of- function; L-CC1-/-); or ii/ forced hepatic CEACAM1 overexpression (gain-of-function; L-CC1Tg). Aim 2.1. Hypothesis: Enhancement of hepatocyte-specific CEACAM1 – β-catenin regenerative functions facilitates hepatoprotection. Aim 2.2. Hypothesis: TIM-3 – CECACAM1 signaling enhances hepatocyte autophagy program. Integration with PPG: By providing novel insights into TIM-3 – CEACAM1 checkpoint regulation at the innate – adaptive immune interface in IR-stressed iso-OLT, Project I naturally informs/precedes studies assessing how host rejection regulates innate immune activation/IRI sequel in allo-OLT (Project II). Direct application of approaches blunting inflammation while promoting hepatoprotection in mouse OLT models will accelerate assessments of immune phenotypes in human liver transplants (Project III).