LYMPHOCYTE RECRUITMENT BY VASCULAR ADHESION MOLECULES

淋巴细胞归巢到炎症部位是由血管内皮上的黏附分子与其在淋巴细胞表面的配体之间的相互作用引导的。携带合适配体的淋巴细胞的归巢可能是由血管粘附分子的选择性表达决定的。我的假设是，皮肤微血管内皮具有粘附分子e -选择素、VCAM-1和ICAM-1的特征表达谱，与其他组织不同，这是细胞因子反应性和粘附分子表达持续时间的函数。我将确定内皮粘附分子表达的这些组织特异性差异是否会导致携带特定粘附分子配体的淋巴细胞亚群的选择性募集。1)构建嵌合人类免疫缺陷小鼠模型，比较人类淋巴细胞与来自皮肤、肺、皮下脂肪和脐静脉的内皮细胞之间的相互作用；2)在体外（器官和细胞培养）和体内系统表征细胞因子刺激下粘附分子表达的组织特异性差异；3)首先用全细胞或同种异体反应细胞耗尽的人PBMC接种嵌合动物，然后使用阻断抗体选择性地干扰粘附分子与配体的相互作用，确定特异性粘附分子组合是否对体内特异性T细胞亚群的募集是必要的；4)在没有其他差异的情况下，通过使用逆转录病毒转导改变内皮粘附分子表达库，确定这些相互作用是否足以选择性地募集淋巴细胞，并评估浸润t细胞表型的影响。提出了一个为期五年的指导计划来验证这一假设。该项目将在具有良好免疫生物学和血管生物学背景的导师（J. Pober）、具有分子生物学专业知识的合作者（a . Bothwell和M. Kluger）以及众多课程和研讨会的指导下，在免疫学和分子生物学领域进行培训。在这段时间结束时，我的目标是成为一名独立的研究者，并对皮肤淋巴细胞募集的理解做出贡献，这可以用于开发具有皮肤特异性活性的抗炎剂。

Lymphocyte homing to sites of inflammation is directed by the interaction between adhesion molecules on the vascular endothelium and their ligands on the surface of the lymphocytes. The homing of lymphocytes bearing the proper ligands to specific organs may be determined by the selective expression of vascular adhesion molecules. It is my hypothesis that the microvascular endothelium of the skin has a characteristic profile expression of the adhesion molecules E-Selectin, VCAM-1, and ICAM-1 that differs from other tissues as a function of cytokine responsiveness and duration of adhesion molecule expression. I will determine whether these tissue specific differences in endothelial adhesion molecule expression result in the selective recruitment of subsets of lymphocytes bearing specific adhesion molecule ligands. This will be accomplished by 1) constructing a chimeric human-immunodeficient mouse model in which to compare the interactions between human lymphocytes and endothelial cells derived from skin, lung, subcutaneous fat and umbilical vein; 2) systematically characterizing tissue specific differences in adhesion molecule expression in response to cytokine stimulation in vitro (in both organ and cell culture) and in vivo; 3) determining whether specific combinations of adhesion molecules are necessary for the recruitment of specific T cell subsets in vivo by first inoculating the chimeric animals with whole or alloreactive cell depleted human PBMC, then using blocking antibodies to selectively interfere with adhesion molecule-ligand interactions; 4) determining whether these interactions are sufficient, in the absence of other differences, for selective lymphocyte recruitment by using retroviral transduction to alter the repertoire of endothelial adhesion molecule expression, and assessing the effect on the phenotype of infiltrating T-cells. A five year mentored program is proposed test this hypothesis. This program will incorporate training in the fields of immunology and molecular biology under the guidance of a mentor (J. Pober) with a well established background in immunobiology and vascular biology, collaborators (A. Bothwell and M. Kluger) with expertise in molecular biology, as well as from numerous courses and seminars. At the end of this period it is my goal to be well established as an independent investigator, and to have made a contribution to the understanding of cutaneous lymphocyte recruitment which could be exploited in the development of anti inflammatory agents with specific activity in the skin.