ICAM-1 MIMICS AS LFA-1 INHIBITORS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 背景和具体目标 白细胞整合素在宿主防御、炎症、止血和转移中的血管细胞粘附中起关键作用。我们的新数据表明，VLA-4对VCAM-1的亲和力可以在特殊的信号环境下通过不同的生理途径进行调节。我们推测，有一个特定的相互作用之间的构象，施加的力，细胞内信号，和粘附功能。 因此，具有操纵构象变化能力的小分子配体可用于阐明VLA-4的功能。 我们建议实现以下具体目标： 1)设计合成已知的VLA-4抑制剂，其抑制模式尚不清楚; 2)研究它们在调节VLA-4及相关整合素中的生物学功能; 3)设计和合成新的VLA-4抑制剂。 结果 我们已经合成了3个已知的有效的和选择性的VLA-4抑制剂及其荧光标记的类似物。 尽管这些化合物已显示出对VLA-4的有效和选择性抑制作用，但它们的抑制和激活模式尚不清楚。 因此，使用这些化合物作为探针来研究VLA-4的功能以及与其他整合素如LFA-1和ICAM-1相关的构象变化具有相当大的生物学和医学意义。 通过与我的导师Sklar及其团队的密切合作，我们进行了VLA-4和其他整合素的研究。 已经确定了非常有趣和重要的发现（一份手稿正在编写中）。 我们的实验室正在使用荧光流式细胞术进行更详细的机制研究。 这些机理的认识将有助于我们设计出更有前景和选择性的VLA-4抑制剂。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Background and Specific Aims Leukocyte integrins play key roles in vascular cell adhesion in host defense, inflammation, hemostasis, and metastasis. Our new data suggest that the affinity of VLA-4 for VCAM-1 can be regulated under special signaling circumstances by distinct physiological pathways. We hypothesize that there is a specific interplay between conformation, applied force, intracellular signaling, and adhesive function. Therefore, small molecule ligands with ability of manipulating the conformational change can be used for elucidating VLA-4 functions. We propose to pursue the following specific aims: 1) Design and synthesize known VLA-4 inhibitors, which inhibition modes are not clear; 2) Study their biolgical functions in regulating the VLA-4 and related integrins; 3) Design and synthesize new VLA-4 inhibitors. Results We have synthesized 3 known potent and selective VLA-4 inhibitors and their fluorescence-labeled analogues. Despite the fact that these compounds have been shown potent and selective inhibitory effect on VLA-4, their inhibition and activation mode are not known. Therefore, the use of these compounds as probes to study the VLA-4 functions, and conformational changes associated with other integrins such as LFA-1 and ICAM-1 is of considerable biological and medicinal significance. With close collaboration with my mentor Sklar and his group, we have conducted studies of VLA-4 and other integrins. Very interesting and important discoveries have been identified (one manuscript in preparation). More detail mechanistic investigations using fluorescent flow cytometry is under way in our laboratories. The mechanistic insights will help us to design more portent and selective VLA-4 inhibitors.