Department of Pathology and Cancer Center, University of New Mexico Health Sciences Center, Albuquerque NM, USA.
Front Immunol. 2012 Aug 2;3:242. doi: 10.3389/fimmu.2012.00242. eCollection 2012.
Very Late Antigen-4 (CD49d/CD29, alpha4 beta1) and Lymphocyte Function-associated Antigen-1 (CD11a/CD18, alphaL beta2) integrins are representatives of a large family of adhesion receptors widely expressed on immune cells. They participate in cell recruitment to sites of inflammation, as well as multiple immune cell interactions. A unique feature of integrins is that integrin-dependent cell adhesion can be rapidly and reversibly modulated in response to cell signaling, because of a series of conformational changes within the molecule, which include changes in the affinity of the ligand binding pocket, molecular extension (unbending) and others. Here, we provide a concise comparative analysis of the conformational regulation of the two integrins with specific attention to the physiological differences between these molecules. We focus on recent data obtained using a novel technology, based on small fluorescent ligand-mimicking probes for the detection of integrin conformation in real-time on live cells at natural receptor abundance.
非常晚期抗原-4（CD49d/CD29，α4β1）和淋巴细胞功能相关抗原-1（CD11a/CD18，αLβ2）整合素是广泛表达于免疫细胞上的一大类粘附受体的代表。它们参与免疫细胞向炎症部位的募集，以及多种免疫细胞的相互作用。整合素的一个独特特征是，由于分子内的一系列构象变化，包括配体结合口袋亲和力的变化、分子伸展（变直）等，整合素依赖性细胞粘附可以快速、可逆地调节，以响应细胞信号转导。在这里，我们对这两种整合素的构象调节进行了简明的比较分析，并特别关注这些分子之间的生理差异。我们重点介绍了使用一种新的基于小分子荧光配体模拟探针的技术获得的最新数据，该技术可以在自然受体丰度下实时检测活细胞中整合素构象。
