Corneal Lymphatics & Adaptive Immunity

描述（由申请人提供）：正常无血管角膜中的新生血管形成可导致视轴受损。在术语“新血管形成”中，血液组分称为血管生成，淋巴组分称为淋巴管生成。相对于单纯疱疹病毒1型（HSV-1）感染，只有血管生成进行了研究。最近，我们已经开始了一项关于角膜感染HSV-1后淋巴管生成的研究，发现这个过程先于血管生成。更重要的是，我们已经发现，响应HSV-1感染的角膜中淋巴管的发生通过与角膜移植后所描述的不同的独特途径进行。具体地说，我们已经发现了一个强大的血管内皮生长因子（VEGF）A反应感染HSV-1 eliminating淋巴管生成角膜上皮细胞通过VEGF受体2（VEGFR 2）介导的途径。该过程不依赖于VEGF C、VEGF受体3或单核细胞/巨噬细胞。我们还发现，新产生的淋巴管能够不依赖于血管生成而将可溶性抗原转运到引流淋巴结。然而，仍然未知的是新创建的淋巴管对引流淋巴结内的宿主免疫应答的贡献以及有助于角膜淋巴管生成的其他炎症介质。我们假设主要由VEGF A驱动的淋巴管发育和响应于感染而局部产生的促炎分子对于诱导引流淋巴结中发现的适应性免疫应答是关键的，所述适应性免疫应答由HSV-1感染小鼠的疱疹性基质角膜炎发展的严重性反映。为了解决这一假设，提出了两个具体目标：具体目标1将解决HSV-1感染后病毒复制和促炎细胞因子表达对角膜淋巴管生成的影响。此外，还将监测白细胞亚群和抗原的运输。具体目标2将阐述淋巴管生成相对于引流淋巴结中适应性免疫应答的发生和HSV-1感染后基质角膜炎的发展的意义。它将进一步解决病毒诱导的VEGF A的产生对CD 4+和CD 8 + T效应细胞的产生的作用，这些细胞有助于病毒监视和角膜发病机制。预期在实现这些目标的过程中，我们将回避促淋巴管生成因子在产生对眼部病理学至关重要的适应性免疫应答中的作用，所述眼部病理学包括使人衰弱的并且有时致盲的基质角膜炎。 公共卫生相关性：淋巴管生成作为驱动针对眼部单纯疱疹病毒1型（HSV-1）感染的适应性免疫应答的中心力量的作用尚未被探索。与HSV-1诱导的血管内皮生长因子（VEGF）-A（一种有效的免疫调节分子）结合，预计该研究将确定HSV-1诱导的淋巴管生成和VEGF-A的产生如何影响对感染的免疫应答，并由此产生一种治疗策略，以改变宿主应答，减弱疱疹性角膜基质炎的发展，并保护视轴。

DESCRIPTION (provided by applicant): Neovascularization in the normally avascular cornea can lead to a compromised visual axis. Within the term "neovascularization" is a blood component referred to as hemangiogenesis and a lymphatic component referred to as lymphangiogenesis. Relative to herpes simplex virus type 1 (HSV-1) infection, only hemangiogenesis has been investigated. Recently, we have initiated a study on lymphangiogenesis following corneal infection with HSV-1 and discovered this process precedes hemangiogenesis. More importantly, we have discovered the genesis of lymphatic vessels in the cornea proper in response to HSV-1 infection operates thru a unique pathway distinct from what has been described following corneal transplantation. Specifically, we have found a robust vascular endothelial growth factor (VEGF) A response by corneal epithelium infected with HSV-1 elicits lymphangiogenesis thru a VEGF receptor 2 (VEGFR2)-mediated pathway. This process is independent of VEGF C, VEGF receptor 3, or monocytes/macrophages. We have also found the newly created lymphatic vessels are capable of transporting soluble antigen to the draining lymph node independent of hemangiogenesis. However, what remains unknown is the contribution of the newly created lymphatic conduit to the host immune response within the draining lymph node as well as other inflammatory mediators that contribute to corneal lymphangiogenesis. We hypothesize lymphatic vessel development driven principally by VEGF A and contributing pro-inflammatory molecules generated locally in response to infection are critical for the induction of the adaptive immune response found in the draining lymph node reflected by the severity in the development of herpetic stromal keratitis of HSV-1 infected mice. To address this hypothesis, two specific aims are proposed: Specific aim 1 will address the impact of viral replication and pro- inflammatory cytokine expression on corneal lymphangiogenesis following HSV-1 infection. In addition, trafficking of leukocyte subpopulations and antigen will be monitored as well. Specific aim 2 will address the significance of lymphangiogenesis relative to the genesis of the adaptive immune response in the draining lymph node and development of stromal keratitis following HSV-1 infection. It will further address the role of virus-induced VEGF A production on the production of CD4+ and CD8+ T effector cells that contribute in viral surveillance and corneal pathogenesis. It is anticipated in accomplishing these goals, we will eludicate the contribution of pro-lymphangiogenesis factors in the generation of the adaptive immune response critical for the ocular pathology that includes the debilitating and sometimes blinding stromal keratitis. PUBLIC HEALTH RELEVANCE: The role of lymphangiogenesis as a central force driving the adaptive immune response to ocular herpes simplex virus type 1 (HSV-1) infection has not been explored. In combination with HSV-1-induced vascular endothelial growth factor (VEGF)-A, a potent immunomodulatory molecule, it is anticipated the study will identify how HSV-1-induced lymphangiogenesis and VEGF-A production influence the immune response to the infection and in so doing, lead to a treatment strategy to alter the host response, attenuate the development of herpetic stromal keratitis, and preserve the visual axis.