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)感染会导致免疫细胞浸润 和角膜混浊，并触发一种称为疱疹间质的严重免疫炎症情况 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 美国和世界各地。目前的HSK治疗，如联合使用抗病毒药物和皮质类固醇，部分是 有效且长期使用会导致严重的局部和全身副作用。此外，多国集团的出现 HSK患者的HSV-1耐药株是一个主要的临床挑战。因此，存在着一种未得到满足的临床 需要开发安全有效的免疫疗法来治疗HSK。选择性地诱导出一种有效的抗- 炎症免疫反应最小激活的病毒状态体现了一种强有力的治疗手段 复发性单纯疱疹病毒性角膜炎患者。在本申请中，我们提出了一种针对IL-27的方法，即 免疫调节细胞因子，诱导角膜术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(MϕS)在启动和 消炎治疗HSK进展期。来自HSV-1的细胞内dsDNA是由环状病毒识别的 GMP-AMP(CGAMP)合成酶(CGAS)并激活干扰素基因刺激物(STING)途径 促进抗病毒免疫。单纯疱疹病毒1型感染MϕS代偿性下调糖酵解促进糖酵解 三羧酸(TCA)循环。我们观察到激活的M-ϕS的三氯乙酸循环被干扰 增加免疫反应基因1(IRG1)的表达，这是一种将柠檬酸转化为衣康酸的酶。 依他康酸是一种免疫调节性线粒体代谢物，既可以起到促病毒作用，也可以起到抗病毒作用。我们的 初步数据提示，眼部单纯疱疹病毒1型感染促进了角膜中irg1的表达，MϕS 通过对cGAS-STING通路的负性调节来抑制抗病毒免疫。除了病原体， 细胞因子调节MϕS的代谢，从而调节其效应功能。我们发现HSV-1诱导IL-1。 27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可减轻HSV-1诱导的糖酵解 M-ϕS代谢抑制IRG1干扰素-β的表达及抑制炎症细胞因子的作用 制作。基于这些观察，我们假设HSV-1对MϕS进行重新编程，以促进IRG1R 避开cGAS-STING介导的抗HSV-1应答(AIM 1)和IL-27减轻HSV-1诱导的糖酵解 M-ϕS体内代谢抑制炎症和促进抗病毒免疫的作用 激活cGAS-STING通路(目标2)。这项研究的主要成果将是揭示HSV-1是如何 在单纯疱疹病毒性肝炎进展过程中调节M-ϕ代谢以逃避抗病毒反应。我们建议的基于IL-27的 该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 疗效，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.