The role of plasmacytoid dendritic cells in corneal immunity

描述（由申请人提供）：浆细胞样树突状细胞（pDC）是一种独特的骨髓来源细胞，在连接先天和适应性免疫反应中起重要作用。pDC通过toll样受体对病毒的识别以及它们产生大量I型干扰素（IFN）的能力，在抵御病毒感染的第一道防线中起着关键作用。在初步研究中，我们发现了一种新的常住pDC在角膜。我们在体内的初步研究表明pDC是角膜中IFN-a的主要来源，并在单纯疱疹性角膜炎（HSK）的宿主防御中发挥保护作用。因此，我们的研究结果表明，pDC是对抗病毒性角膜炎的关键参与者，同时保持视力。确定pDC在HSK中的特定功能，了解pDC与角膜T细胞迁移的关键途径，可能为免疫治疗药物干预提供新的分子靶点。然而，确定器官和细胞特异性分子迁移机制至关重要，以便抑制细胞亚群驱动疾病，而不影响保护性免疫所需的白细胞。为了解决这些问题，我们建立了一种新的多光子活体显微镜（MP-IVM）模型来研究活体小鼠完整角膜中的pDC。这种成像方法使用带有荧光pDC和荧光病毒的转基因小鼠，并将在活体动物中以亚细胞分辨率可视化pDC和病毒，使我们能够研究它们与周围细胞的相互作用。基于前期工作和血管粘附分子和趋化因子的器官特异性组合上调调节pDC和T细胞募集到角膜以及随后pDC从角膜的迁移炎症和感染。我们进一步假设pDC通过局部角膜IFN-?对HSK患者的角膜具有保护作用。和TNF - ?在HSK激活后产生并迁移到dLN的不同区域，在那里它们通过IFN-介导CD4+ T细胞向T调节性或T辅助（Th）17细胞的分化途径。和IL-6的生产。研究pDC是为了研究引导他们进入正常角膜和发炎角膜的交通信号，并将用于解决以下两个具体目标：表征角膜pDC并剖析炎症过程中介导其募集和释放的分子机制；2)。表征角膜pDC并剖析炎症过程中介导其募集和释放的分子机制。识别这些细胞进出角膜的关键途径将为炎症、感染性、同种免疫和自身免疫性疾病的药物干预提供新的和高度特异性的分子靶点。近几十年来，眼科领域出现的有效抗炎药物很少，迫切需要新的抗炎药物。HSK是导致失明的主要原因。有效的HSK治疗可以显著减轻视力损害，提高工作效率，减轻HSK治疗负担。

DESCRIPTION (provided by applicant): Plasmacytoid dendritic cells (pDC), a distinct type of bone marrow-derived cell, play an important role in linking innate and adaptive immune responses. pDC are pivotal in the first line of defense against viral infections through recognitio of viruses by toll-like receptors as well as their ability to produce large amounts of type I interferons (IFN). In preliminary studies, we have discovered a novel population of resident pDC in the cornea. In vivo pDC depletion in our preliminary studies demonstrate that pDC are the major source of IFN-a in the cornea and play a protective role in the host defense in herpes simplex keratitis (HSK). Thus our results suggest that pDC are key participants in fighting viral keratitis, while preserving vision. Identifying specific functions of pDC in HSK and understanding the critical pathways of pDC and T cell migration in the cornea may provide new molecular targets for pharmacological intervention through immunotherapy. However, defining organ- and cell-specific molecular migratory mechanisms is critical, in order to inhibit cell subsets driving disease, without affecting leukocytes required for protective immunity. To address these questions, we have developed a new multiphoton intravital microscopy (MP-IVM) model to study pDC in intact corneas of living mice. This imaging approach uses transgenic mice, with fluorescent pDC, and fluorescent viruses, and will visualize pDC and viruses at subcellular resolution in living animals, allowing us to study their interaction with surrounding cells. Based on preliminary work and that up-regulation of organ-specific combination of vascular adhesion molecules and chemokines regulate pDC and T cell recruitment to the cornea and subsequent migration of pDC from the cornea in inflammation and infection. We further hypothesize that pDC are protective to the cornea in HSK through local corneal IFN-? and TNF-? production and migrate to distinct areas of the dLN after activation in HSK, where they mediate differentiation pathways of CD4+ T cells to T regulatory or T helper (Th)17 cells through IFN-? and IL-6 production. pDC will be studied to investigate the traffic signals that guide them to normal and inflamed corneas and will be used to address the following two specific aims: 1.) To characterize corneal pDC and dissect the molecular mechanisms that mediate their recruitment and egress during inflammation; 2.) To characterize corneal pDC and dissect the molecular mechanisms that mediate their recruitment and egress during inflammation. Identification of these critical pathways of cell migration to and from the cornea will provide new and highly specific molecular targets for pharmacological intervention in inflammatory, infectious, alloimmune and autoimmune diseases. Few effective anti-inflammatory drugs have emerged over the last decades in the ophthalmic field and an urgent need for new drugs exists. HSK is a leading cause of blindness. Effective therapy for HSK would significantly reduce visual impairment, increase productivity, and reduce the burden of treating HSK.