IL-27-mediated immunoregulation in HSV-1-induced stromal keratitis

项目摘要 在眼部感染中，复发性单纯疱疹病毒-1（HSV-1）感染引起免疫细胞浸润 和角膜混浊，并引发一种称为疱疹性基质的严重免疫炎症状况 角膜炎（HSK）。HSK是一种痛苦的疾病，也是美国传染性失明的主要原因之一。 国家和全世界。目前的HSK治疗，如抗病毒药物联合皮质类固醇，部分 长期使用会引起严重的局部和全身副作用。此外，多个国家的出现， HSK患者中的耐药HSV-1菌株是一个重大的临床挑战。因此，存在未满足的临床 需要开发安全有效的免疫疗法来治疗HSK。选择性诱导一种有效的抗- 具有最小炎症免疫应答激活的病毒状态体现了治疗的有力手段 复发性HSK患者。在本申请中，我们提出了一种靶向IL-27的方法， 免疫调节细胞因子，以诱导角膜移植后内源性抗病毒和抗炎反应 HSV-1感染抑制HSK进展。巨噬细胞在启动和 缓解HSK进展过程中的炎症。来自HSV-1的细胞内双链DNA被环- GMP-AMP（cGAMP）合酶（cGAS）并激活干扰素基因刺激因子（STING）途径， 增强抗病毒免疫力。HSV-1感染的巨噬细胞促进糖酵解，代偿性下调 三羧酸（TCA）循环。我们观察到活化的M β细胞中的TCA循环被破坏， 免疫应答基因1（Irg 1）表达增加，这是一种将柠檬酸盐转化为衣康酸盐的酶。 衣康酸是一种免疫调节线粒体代谢产物，可以发挥促病毒和抗病毒作用。我们 初步数据表明，眼部HSV-1感染可促进角膜和结膜中Irg 1的表达， 通过cGAS-STING途径的负调节抑制抗病毒免疫。除了病原体， 细胞因子调节巨噬细胞中的代谢以调节其效应子功能。我们发现，HSV-1诱导IL-1， IL-27受体在角膜中表达，缺乏IL-27受体的小鼠对眼部HSV-1高度易感 病毒滴度和HSK严重程度增加的感染。我们发现IL-27减弱HSV-1诱导的糖酵解， 抑制Irg 1表达，刺激IFN-β，限制炎症细胞因子 生产基于这些观察结果，我们假设HSV-1重编程M β 1，以促进Irg 1， 逃避cGAS-STING介导的抗HSV-1应答（Aim 1）和IL-27减弱HSV-1诱导的糖酵解 通过抑制Irg 1的表达， 激活cGAS-STING途径（Aim 2）。这项研究的主要结果将是揭示HSV-1是如何在 在HSK进展过程中，调节M β代谢以逃避抗病毒应答。我们提出的IL-27 这种方法将补充目前的抗病毒和免疫抑制HSK疗法，以增加他们的免疫功能。 功效，从而降低副作用的风险。

Project Summary Among ocular infections, recurrent herpes simplex virus-1 (HSV-1) infection causes immune cell infiltration and opacity in the cornea and triggers a severe immuno-inflammatory condition called herpetic stromal keratitis (HSK). HSK is a painful condition and one of the leading causes of infectious blindness in the United States and worldwide. Current HSK treatments, such as anti-virals combined with corticosteroids, are partially effective, and prolonged use causes severe local and systemic side effects. Further, the emergence of multi- drug-resistant HSV-1 strains in HSK patients is a major clinical challenge. Therefore, there is an unmet clinical need to develop safe and effective immunotherapies to treat HSK. The selective induction of a potent anti- viral state with minimal activation of inflammatory immune responses embodies a powerful means to treat patients with recurrent HSK. In this application, we propose one such approach targeting IL-27, an immunoregulatory cytokine, to induce endogenous anti-viral and anti-inflammatory responses after corneal HSV-1 infection to suppress HSK progression. Macrophages (Mϕs) play a central role in initiating and resolving inflammation during HSK progression. Intracellular dsDNA from HSV-1 is recognized by cyclic- GMP-AMP (cGAMP) synthase (cGAS) and activates the stimulator of interferon genes (STING) pathway to promote anti-viral immunity. HSV-1 infected Mϕs promote glycolysis with compensatory downregulation of the tricarboxylic acid (TCA) cycle. We observed that the TCA cycle in activated Mϕs is disrupted with increased immune-responsive gene 1 (Irg1) expression, an enzyme that converts citrate to itaconate. Itaconate is an immunoregulatory mitochondrial metabolite that can play both pro- and anti-viral roles. Our preliminary data suggest that ocular HSV-1 infection promotes Irg1 expression in the cornea and Mϕs to suppress anti-viral immunity through negative regulation of the cGAS-STING pathway. Apart from pathogens, cytokines regulate metabolism in Mϕs to modulate their effector functions. We show that HSV-1 induces IL- 27 expression in the cornea, and mice lacking the IL-27 receptor are highly susceptible to ocular HSV-1 infection with increased viral titers and HSK severity. We show that IL-27 attenuates HSV-1-induced glycolytic metabolism in Mϕs and suppresses Irg1 expression to stimulate IFN-β and limit inflammatory cytokine production. Based on these observations, we hypothesize that HSV-1 reprograms Mϕs to promote the Irg1 to evade cGAS-STING-mediated anti-HSV-1 responses (Aim 1) and IL-27 attenuates HSV-1-induced glycolytic metabolism in Mϕs to suppress inflammation and promote anti-viral immunity through inhibition of Irg1 to activate cGAS-STING pathway (Aim 2). The primary outcome of this study will be to uncover how HSV-1 regulates Mϕ metabolism to evade anti-viral responses during HSK progression. Our proposed IL-27-based approach will complement the current anti-viral and immunosuppressive HSK therapies to increase their efficacy, thus lowering the risk of side effects.