HUMAN-MOUSE CHIMERAS--A MODEL FOR VASCULAR CELL BIOLOGY

白细胞通过血管内皮细胞黏附和迁移 细胞黏附分子(CAM)在程序化和程序化表达 顺序方式。因为炎症反应发生在 剪切力、细胞因子、化学诱导剂、细胞外 体内基质结构和多种细胞类型的存在 需要模特。这项提案的总体目标是开发新的 活体模型将允许研究人类内皮细胞-白细胞 相互作用，这将允许使用许多抗CAM抗体 在人类细胞培养模型中开发的，不会与 动物CAM并解决外推动物发现中的问题 对人类来说。 为了做到这一点，移植了几块正常的人类皮肤。 感染免疫缺陷(SCID)小鼠。免疫组织化学分析显示 据透露，这些人类皮肤移植物与正常皮肤非常相似， 维持他们的人体血管系统，有能力上调CAM 例如E-Selectin和ICAM-1，并且能够支持活动的 小鼠白细胞向细胞因子迁移的炎症反应- 注射区域。我们的具体目标是： 1.进一步描述关于以下方面的人类皮肤/SCID模型：a. 血管内皮细胞表达的体内调控及动力学研究 黏附分子(包括P-选择素、E-选择素、ICAM-1、VCAM-1和 PECAM-1)在选定的细胞因子引起的炎症反应中， 化学诱导剂、内毒素、细菌感染和肥大细胞 脱颗粒。 B.确定哪些细胞因子或细胞因子/趋化物质组合 白血球(包括小鼠和人)迁移到 纸巾。 2.使用针对人内皮细胞的特异性生物活性抗体 黏附分子和糖类模拟物对CAM配体的测定 内皮细胞黏附分子在白细胞浸润中的作用 特别关注E-选择素和一种新的血管黏附 分子，PECAM-1。 3.定义控制特定类型的 注射人类白细胞(即中性粒细胞与嗜酸性粒细胞 淋巴细胞)针对特定类型的炎症反应。 4.通过发展一种微血管床来表征第二类型的微血管床 利用移植的人支气管组织构建新的人/SCID嵌合体。 这些研究将使我们更好地理解黑色素瘤 人在体微血管中白细胞与内皮细胞的相互作用。 这些信息，以及测试特定能力的能力 在人体内诱导或抑制白细胞迁移的药物 模型，将在设计新的治疗剂方面非常有用。

Leukocytes adhere to and migrate through the endothelium using specific cell adhesion molecules (CAM's) that are expressed in a programmed and sequential manner. Because the inflammatory response occurs in the context of shear stress, cytokines, chemoattractants, extracellular matrix structures, and the presence of multiple cell types, in vivo models are needed. The overall goal of this proposal is to develop new in vivo models that will allow study of human endothelial cell-leukocyte interactions, This will allow the use of many of the anti-CAM antibodies developed in human cell culture models that do not cross-react with animal CAM's and address the problems in extrapolating animal findings to humans. To accomplish this, pieces of normal human skin have been transplanted onto immunodeficient (SCID) mice. Immunohistochemical analysis has revealed that these human skin grafts closely resemble normal skin, maintain their human vasculature, have the ability to upregulate CAM's such as E-Selectin and ICAM-1, and have the ability to support an active inflammatory reaction with migration of murine leukocytes into cytokine- injected areas. Our specific aims are to: 1. Further characterize the human skin/SCID model with regard to: A. the in vivo regulation and kinetics of expression of endothelial cell adhesion molecules (including P-Selectin, E-Selectin, ICAM-1, VCAM-1, and PECAM-1) during inflammatory reactions induced by selected cytokines, chemoattractants, endotoxin, bacterial infection, and mast cell degranulation. B. Determine which cytokine or cytokine/chemoattractant combinations are necessary for white blood cell (both murine and human) migration into tissues. 2. Use specific bioactive antibodies against human endothelial cell adhesion molecules and carbohydrate mimics of CAM ligands to determine the functional role of endothelial cell CAM's in leukocyte infiltration with special attention to E-selectin and a novel vascular adhesion molecule, PECAM-1. 3. Define parameters that control the ability of specific types of injected human white blood cells (i.e neutrophils vs eosinophils vs lymphocytes) to be targeted to specific types of inflammatory reactions. 4. Characterize a second type of microvascular bed by development of a new human/SCID chimera utilizing transplanted human bronchial tissue. These studies will lead to an enhanced understanding of the biology of leukocyte-endothelial cell interactions in human in situ microvessels. This information, along with the ability to test the ability of specific agents to induce or inhibit leukocyte emigration in a human in vivo model, will be extremely useful in designing novel therapeutic agents.