Leukocyte Trafficking: From Flow Blood to Tissue

描述(申请人提供)：这项生物工程研究伙伴计划结合了莱斯大学生物工程系和贝勒医学院白细胞生物学分部的专业知识，研究了白细胞从流动的血液移动到组织中迁移所涉及的详细的顺序过程。提出了一种系统的方法，目的是确定每个步骤所涉及的关键分子机制，然后整合这些步骤，就像在体内发生的那样。将采用体外和体内(主要是小鼠)模型--前者用于测试特定的分子假说，后者用于确保体外确定的机制在实际的体内环境中具有重要意义。提出了三个具体目标：1.流体剪切效应及白细胞与内皮细胞相互作用对贴壁白细胞影响的研究。本课题将利用锥板粘度计和平行板流动系统研究剪切对中性粒细胞分泌功能和表型变化的影响。2.剪切条件下白细胞与内皮细胞的相互作用及其对血管通透性的影响。本研究将利用体外和体内实验模型研究中性粒细胞黏附和迁移的部位，以及内皮和血管通透性的变化。目的3.研究白细胞通过细胞外基质迁移的机制，以及通过内皮迁移所需过程所引起的表型变化。这一目标将利用合成的细胞外基质模拟物在体外研究蛋白质分解、黏附和触觉趋化的贡献，并在体内显微镜下研究细胞外基质在体内的迁移。基本的生物工程专业知识对于每个具体目标的成功和AIMS的整合至关重要--涉及生物力学、运输现象、复杂生物系统、细胞工程和生物材料的各个方面。我们相信，这些跨学科研究的结果，结合定量生物工程模型、新型生物材料、基础白细胞生物学和基础血管生物学，将使我们对白细胞运输的理解取得重大进展，对正常生理和各种病理状态都具有重要意义。

DESCRIPTION (provided by applicant): This Bioengineering Research Partnership proposal combines expertise from the Bioengineering Department at Rice University and the Section of Leukocyte Biology from Baylor College of Medicine to examine the detailed sequential processes involved in movement of leukocytes from flowing blood to migration in tissues. A systems approach is presented, with the goal of identifying the crucial molecular mechanisms involved at each step and then integration of the steps as would occur in vivo. Both in vitro and in vivo (principally mice) models will be employed - the former to test specific molecular hypotheses and the latter to ensure that mechanisms identified in vitro are of importance in the actual in vivo setting. Three specific aims are proposed Specific Aim 1 The study of the effects of fluid shear and the interactions of leukocytes and endothelial cells on adherent leukocytes. This aim will use cone-plate viscometry and parallel plate flow systems to investigate the influence of shear on secretory functions and phenotypic changes in adherent neutrophils Specific Aim 2. The study of the interactions of leukocytes and endothelial cells under shear conditions and the effects on vascular permeability. This aim will use both in vitro and in vivo experimental models to investigate the sites of neutrophil adhesion and transmigration, and changes in endothelial and vascular permeability Specific Aim 3. The study of the mechanisms of leukocyte migration through extracellular matrix, and the phenotypic changes induced by the processes required for transendothelial migration. This aim will utilize a synthetic mimetic of extracellular matrix to investigate the contributions of proteolysis, adhesion and haptotaxis in vitro, and intravital microscopy to investigate migration through extracellular matrix in vivo. Basic bioengineering expertise is crucial for the success of each Specific Aim and for the integration of aims - involving aspects of biomechanics, transport phenomena, complex biological systems, cellular engineering and biomaterials. We believe the results of these interdisciplinary studies, combining quantitative bioengineering models, novel biomaterials, basic leukocyte biology and fundamental vascular biology will lead to significant advances in our understanding of leukocyte trafficking, with important implications in both normal physiology and various pathological states.