Ocular Lymphangiogenesis

描述（由申请人提供）：新生血管和淋巴管生成是由于炎症在正常无血管的角膜中发生的不良事件。因此，视力可能会受到损害，在感染的情况下，通过引流淋巴结内效应细胞的“教育”，适应性免疫反应随之而来。对于病毒感染的角膜，BALB/c小鼠在感染后7-10天内出现了强烈的血管生成反应，新血管生长。我们发现野生型（WT） C57BL/6小鼠角膜急性单纯疱疹病毒1型（HSV-1）感染也会发生淋巴管生成。然而，与角膜移植模型不同，我们发现眼部HSV-1感染后淋巴血管的发育不需要单核细胞或巨噬细胞。此外，在眼部HSV-1感染模型中，淋巴管生成依赖于血管内皮生长因子（VEGF）受体2 （VEGFR2）配体，而不依赖于VEGF受体3配体，这暗示了VEGF- a和可能的胎盘生长因子。这是角膜淋巴管生成的独特发现，也是我们希望继续研究的。具体来说，我们想要验证HSV-1介导的淋巴管生成是通过HSV-1感染的上皮细胞表达VEGF-A而发生的，并且所产生的淋巴管是功能性的，有助于对HSV-1产生适应性免疫反应。为了验证这一假设，提出了两个具体目标：具体目标1将通过鉴定纵向表达VEGF- a的细胞来解决VEGF- a在病毒诱导的淋巴管生成中的作用，确定VEGF- a表达的机制，并确定其他因素（如IL-6、VEGF- c和VEGF- D）对HSV-1感染后淋巴管生成的贡献。特异性目标2将通过识别感染后从角膜到引流淋巴结的细胞来确定新形成的淋巴管的功能，并确定从hsv -1感染的小鼠中获得的淋巴结细胞的抗原驱动反应，这些细胞表达或不表达角膜淋巴管。为了实现这些目标，我们应该阐明驱动hsv -1诱导的角膜淋巴管生成的因素的贡献，并确定淋巴管在产生适应性免疫反应中的作用，这对随后的间质角膜炎至关重要。确定与淋巴管生成相关的机制可能会突出新分子/途径，这些新分子/途径对淋巴管的发育及其对适应性免疫反应的发展有重要贡献。由于T细胞与间质角膜炎的发展和严重程度相关，因此确定影响效应T细胞发展的其他途径可能提供抑制疾病和保持视力的靶标。

DESCRIPTION (provided by applicant): Neovascularization and lymphangiogenesis are undesirable events that often transpire in the normally avascular cornea as a result of inflammation. As a consequence, visual acuity can be compromised and in the case of infection, an adaptive immune response ensues through the "education" of effector cells within the draining lymph nodes. In response to virus infection of the cornea, a strong angiogenic response has been noted with new blood vessel growth within 7-10 days post infection in BALB/c mice. We have found lymphangiogenesis also occurs in response to acute herpes simplex virus type 1 (HSV-1) infection of the cornea in wild type (WT) C57BL/6 mice. However, unlike the corneal transplant model, we have found lymphatic vessel development in response to ocular HSV-1 infection does not require monocyte or macrophages. Furthermore, in this model of ocular HSV-1 infection lymphangiogenesis is dependent on vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) ligands but not VEGF receptor 3 ligands implicating VEGF-A and possibly placental growth factor. This is a unique finding for lymphangiogenesis in the cornea and one we wish to pursue. Specifically, we would like to test the hypothesis that HSV-1-mediated lymphangiogenesis occurs thru VEGF-A expression by HSV-1-infected epithelial cells and the lymphatic vessels created are functional and contribute to the generation of the adaptive immune response to HSV- 1. In order to test the hypothesis, two specific aims are proposed: Specific aim 1 will address the role of VEGF-A in virus-induced lymphangiogenesis by identifying the cells that express VEGF-A longitudinally, determine the mechanism involved in VEGF-A expression, and define the contribution of other factors (e.g., IL-6, VEGF-C, and VEGF- D) to lymphangiogenesis following HSV-1 infection. Specific aim 2 will address the functionality of the newly created lymphatic vessels by identifying the cells that traffic from the cornea to the draining lymph nodes at times post infection and determine the antigen-driven response of lymph node cells obtained from HSV-1-infected mice that either do or don't express corneal lymph vessels. In accomplishing these goals, we should eludicate the contribution of factors that drive HSV-1-induced corneal lymphangiogenesis and define the role of the lymphatic vessels in the generation of the adaptive immune response critical for ensuing stromal keratitis. PUBLIC HEALTH RELEVANCE The identification of mechanism(s) associated with lymphangiogenesis may highlight novel molecules/pathways that significantly contribute to the development of lymphatic vessels as well as their contribution to the development of the adaptive immune response. Since T cells are associated with the development and severity of stromal keratitis, the identification of additional pathways that influence the development of effector T cells may provide targets to suppress the disease and preserve visual acuity.