L-SELECTIN LIGAND MEDIATING LEUKOCYTE ADHESION

这项研究的总体目标是阐明分子 介导渐进性蓄积的白细胞与 在发生组织损伤的部位有序堆积白细胞 发炎。具体目标是(I)识别受体和配体 由白细胞表达，促进白细胞与白细胞之间的黏附 生理血流条件，(Ii)确定特定受体- 流动或滚动的白细胞与黏附物的配基相互作用 白细胞体外培养。以及(Iii)确定是否抑制这些 受体-配体的相互作用消除了白细胞在体内的积聚。 使用流动室在体外塑造白细胞聚集。 纯化的黏附分子或黏附的白细胞作为 用于白细胞与转基因细胞系黏附的底物 控制流率。抗体封闭和转染体的使用 差异表达的单个黏附分子，如L-选择素 和P-选择素糖蛋白配体-1，将决定相对 这些分子对白细胞聚集的贡献。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盐化 调节白细胞与白细胞的黏附。最后，白细胞在体内的积累 活体将使用小鼠体内小静脉的显微镜进行评估 提睾肌。特异性黏附受体在细胞黏附调节中的作用 白细胞在体内的积累将通过基因靶向的小鼠来验证， 包括L基因缺失的突变体，-选择素。理解分子 白细胞聚集的决定因素将提供对机制的洞察 炎症组织损伤、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.