L-SELECTIN LIGAND MEDIATING LEUKOCYTE ADHESION

这项研究的总体目标是阐明分子 介导进行性蓄积的白细胞之间的整合， 白细胞在进展中的组织损伤部位的有序堆积， 炎症具体目标是（i）鉴定受体和配体 由白细胞表达，其促进白细胞-白细胞粘附 生理流动的条件，（ii）确定特定的受体- 流动或滚动的白细胞和粘附的白细胞之间的配体相互作用 白细胞体外培养以及（iii）确定这些抑制是否 受体-配体相互作用消除体内白细胞积聚。 白细胞积聚将在体外使用流动室进行成型， 纯化的粘附分子或粘附的白细胞用作 白细胞和转染细胞系的粘附基质， 控制流量。抗体阻断和转染子的应用 差异表达单个粘附分子，如L-选择素 和P-选择素糖蛋白配体-1，将决定 这些分子对白细胞积聚的贡献。此外 将用酶处理白细胞和细胞系，以确定 糖基化的作用。受体配体的唾液酸化和硫酸化 介导白细胞-白细胞粘附。最后， 将使用小鼠小静脉的活体显微镜来评估体内 提睾肌特异性粘附受体介导的 使用基因靶向小鼠验证体内白细胞积累， 包括缺乏L，β-选择素的突变体。了解分子 白细胞积聚的决定因素将提供深入了解机制 炎性组织损伤、再灌注损伤和伤口愈合。

The overall objective of this research is to elucidate molecular integrations between leukocytes which mediate progressive accumulation and ordered packing of leukocytes at sites of evolving tissue injury and inflammation. Specific aims are (i) to identify receptors and ligands expressed by leukocytes that facilitate leukocyte-leukocyte adhesion under conditions of physiological flow, (ii) to determine specific receptor- ligand interactions between flowing or rolling leukocytes and adherent leukocytes in vitro. and (iii) to determine if inhibition of these receptor-ligand interactions abolish leukocyte accumulation in vivo. Leukocyte accumulation will be molded in vitro using a flow chamber in which purified adhesion molecules or adherent leukocytes serve as substrates for adhesion of leukocytes and transfected cell lines infused at controlled flow rates. Antibody blockade and use of transfectants differentially expressing individual adhesion molecules, such as L-selectin and P-selectin glycoprotein ligand-1, will determine the relative contribution of these molecules to leukocyte accumulation. In addition leukocytes and cell lines will be treated with enzymes to determine the role of glycosylation. sialylation and sulfation of receptor ligands mediating leukocyte-leukocyte adhesion. Finally,leukocyte accumulation in vivo will be assessed using intravital microscopy of venules in the mouse cremaster muscle. The role of specific adhesion receptors mediating leukocyte accumulation in vivo will be verified using gene-targeted mice, including mutants deficient in l,-selectin. Understanding the molecular determinants of leukocyte accumulation will provide insight into mechanisms of inflammatory tissue injury, reperfusion injury, and wound healing.