Survival Function of the Fadd-Caspase-8-Flip Complex - MERIT Extension

其中FADD-caspase-8-flip复合体控制RIPK3-MLKL介导的细胞死亡，是一种 肿瘤坏死因子及其相关配体参与的炎性细胞死亡过程，TLR信号转导(涉及TRIF) 和干扰素。坏死性下垂与发育和成人动态平衡有关。通过基因 模型和体外细胞实验，我们已经了解到RIPK1在坏死性下垂中扮演着不同的角色， 在不同的环境中促进或抑制这一过程。我们的中心假设，基于我们发表的 和广泛的初步数据，是FADD-caspase-8-flip与RIPK1-RIPK3-MLKL的相互作用是 在调节炎症性疾病方面具有根本性的重要性。基于这一假设，我们将提出：1. FADD-caspase-8-flip和RIPK1在RIPK3调控中的作用？在这里，我们将探索 RIPK1通过募集FADD-1对RIPK3和坏死性下垂的正负调节作用 Caspase-8-翻转到坏死体复合体及其激酶失活形式的抑制功能。基于单元格 体外研究将阐明RIPK1如何执行这些功能，我们将把这些应用于我们的悖论 发现RIPK1的激酶失活突变体可能无法挽救FADD-或caspase-的胚胎致死性 8基因缺陷小鼠。2.FADD-caspase-8-Flip和RIPK1的生存功能是如何发挥作用的？ 炎症性疾病？在这里，我们将使用新的遗传模型(带有RIPK3等位基因的小鼠，小鼠 含有caspase-8的突变体具有caspase-8的存活但不具有凋亡功能)探索几个 提示有细胞凋亡或坏死性下垂的炎症状态。3.怎么做？ FADD-caspase-8-Flip和RIPK3-MLKL抑制Alps？而自身免疫性淋巴组织增生性 在CD95/CD95L缺陷的背景下对综合征(Alps)进行了数十年的研究，对此知之甚少 这种疾病的发病机制主要是由于CD95缺陷的骨髓无法将 综合症。相反，我们发现casp8-/-RIPK3-/-动物中的阿尔卑斯很容易转移到wt。 收件人。我们将利用这一点，以及我们的新遗传模型，来探索这种综合征。这个 从头到尾，拟议的研究都是为了加深对RIPK1功能的理解 与FADD-caspase-8-flip和RIPK3-MLKL的相互作用，这是两条通往不同形式细胞的相互作用途径 死亡。通过这些正在进行的调查，我们将扩大我们对监管如何 RIPK1-RIPK3-MLKL轴受FADD-caspase-8-Flip的作用影响炎症性疾病。

Necroptosis, in which the FADD-caspase-8-FLIP complex controls RIPK3-MLKL-mediated cell death, is an inflammatory cell death process that is engaged by TNF and related ligands, TLR signaling (involving TRIF) and interferons. Necroptosis has been implicated in development and adult homeostasis. Through genetic models and in vitro cell-based experiments, we have learned that RIPK1 plays contrasting roles in necroptosis, either promoting or inhibiting the process in different settings. Our central hypothesis, based on our published and extensive preliminary data, is that the interaction of FADD-caspase-8-FLIP with RIPK1-RIPK3-MLKL is fundamentally important in the regulation of inflammatory diseases. Based on this hypothesis, we will ask: 1. How do FADD-caspase-8-FLIP and RIPK1 function in the regulation of RIPK3? Here we will explore the roles of RIPK1 in positively and negatively regulating RIPK3 and necroptosis, both by recruiting FADD- caspase-8-FLIP to the necrosome complex and the inhibitory function of its kinase-inactive form. Cell-based in vitro studies will elucidate how RIPK1 performs these functions, and we will apply these to our paradoxical finding that the kinase-inactive mutant of RIPK1 may not rescue the embryonic lethality of FADD- or caspase- 8-deficient mice. 2. How do the survival functions of FADD-caspase-8-FLIP and RIPK1 function in inflammatory disease? Here we will employ novel genetic models (mice with a floxed allele of RIPK3, mice harboring a caspase-8 mutant with the survival but not the apoptotic function of caspase-8) to explore several inflammatory conditions in which involvement of apoptosis or necroptosis has been suggested. 3. How do FADD-caspase-8-FLIP and RIPK3-MLKL suppress ALPS? While autoimmune lymphoproliferative syndrome (ALPS) has been studied for decades in the context of CD95/CD95L defects, little is known about the pathogenesis of this disease, largely due to an inability of CD95-deficient bone marrow to transfer the syndrome. In contrast, we have found that ALPS in casp8-/-ripk3-/- animals is readily transferred to wt recipients. We will exploit this, and our novel genetic models, in the exploration of this syndrome. The proposed studies, throughout, are designed to provide a deeper understanding into the functions of RIPK1 interactions with FADD-caspase-8-FLIP, and RIPK3-MLKL, two interacting pathways to different forms of cell death. Through these ongoing investigations, we will extend our fundamental insights into how the regulation of the RIPK1-RIPK3-MLKL axis by the function of FADD-caspase-8-FLIP impacts on inflammatory diseases.