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

白细胞粘附并通过内皮细胞迁移， 细胞粘附分子（CAM），表达在一个程序化的， 顺序的方式。 因为炎症反应发生在 切应力背景，细胞因子，趋化因子，细胞外 基质结构和多种细胞类型的存在， 需要模型。 该提案的总体目标是开发新的 允许研究人内皮细胞-白细胞的体内模型 这将允许使用许多抗CAM抗体， 在人类细胞培养模型中开发， 动物CAM的和解决的问题，在推断动物的发现 对人类 为了实现这一点，正常人的皮肤被移植到 免疫缺陷（SCID）小鼠。 免疫组织化学分析 揭示了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的 如E-选择素和ICAM-1，并具有支持活性的能力， 小鼠白细胞向细胞因子迁移的炎症反应 注入区。 我们的具体目标是： 1.进一步表征人皮肤/SCID模型的以下方面：A.的 内皮细胞表达体内调控和动力学 粘附分子（包括P-选择素、E-选择素、ICAM-1、VCAM-1和 PECAM-1）在由选择的细胞因子诱导的炎症反应期间， 趋化因子、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/化学引诱物组合 白色血细胞（鼠和人）迁移到 组织中 2.使用针对人内皮细胞的特异性生物活性抗体 粘附分子和CAM配体的碳水化合物模拟物， 内皮细胞CAM在白细胞浸润中的功能作用 特别关注E-选择素和一种新的血管粘连 分子PECAM-1。 3.定义控制特定类型的 注射人白色血细胞（即嗜中性粒细胞vs嗜酸性粒细胞vs 淋巴细胞）靶向特定类型的炎症反应。 4.第二种微血管床的特征是： 利用移植的人支气管组织的新的人/SCID嵌合体。 这些研究将有助于加深对生物学的理解。 人原位微血管中白细胞-内皮细胞相互作用。 这些信息，沿着能力测试的具体能力 体内诱导或抑制人白细胞移出的试剂 模型，将是非常有用的设计新的治疗药物。

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.