Yáñez-Mó M, Alfranca A, Cabañas C, Marazuela M, Tejedor R, Ursa M A, Ashman L K, de Landázuri M O, Sánchez-Madrid F
Servicio de Inmunología, Hospital de la Princesa, Universidad Autónoma de Madrid.
J Cell Biol. 1998 May 4;141(3):791-804. doi: 10.1083/jcb.141.3.791.
Cell-to-cell junction structures play a key role in cell growth rate control and cell polarization. In endothelial cells (EC), these structures are also involved in regulation of vascular permeability and leukocyte extravasation. To identify novel components in EC intercellular junctions, mAbs against these cells were produced and selected using a morphological screening by immunofluorescence microscopy. Two novel mAbs, LIA1/1 and VJ1/16, specifically recognized a 25-kD protein that was selectively localized at cell-cell junctions of EC, both in the primary formation of cell monolayers and when EC reorganized in the process of wound healing. This antigen corresponded to the recently cloned platelet-endothelial tetraspan antigen CD151/PETA-3 (platelet-endothelial tetraspan antigen-3), and was consistently detected at EC cell-cell contact sites. In addition to CD151/PETA-3, two other members of the tetraspan superfamily, CD9 and CD81/ TAPA-1 (target of antiproliferative antibody-1), localized at endothelial cell-to-cell junctions. Biochemical analysis demonstrated molecular associations among tetraspan molecules themselves and those of CD151/ PETA-3 and CD9 with alpha3 beta1 integrin. Interestingly, mAbs directed to both CD151/PETA-3 and CD81/ TAPA-1 as well as mAb specific for alpha3 integrin, were able to inhibit the migration of ECs in the process of wound healing. The engagement of CD151/PETA-3 and CD81/TAPA-1 inhibited the movement of individual ECs, as determined by quantitative time-lapse video microscopy studies. Furthermore, mAbs against the CD151/PETA-3 molecule diminished the rate of EC invasion into collagen gels. In addition, these mAbs were able to increase the adhesion of EC to extracellular matrix proteins. Together these results indicate that CD81/TAPA-1 and CD151/PETA-3 tetraspan molecules are components of the endothelial lateral junctions implicated in the regulation of cell motility, either directly or by modulation of the function of the associated integrin heterodimers.
细胞间连接结构在细胞生长速率控制和细胞极化过程中发挥关键作用。在内皮细胞（EC）中，这些结构还参与血管通透性调节和白细胞外渗过程。为了鉴定内皮细胞间连接中的新成分，我们制备了针对这些细胞的单克隆抗体（mAb），并通过免疫荧光显微镜形态学筛选进行选择。两种新型单克隆抗体LIA1/1和VJ1/16特异性识别一种25-kD蛋白，该蛋白选择性地定位于内皮细胞的细胞间连接处，无论是在细胞单层的初始形成过程中，还是在内皮细胞在伤口愈合过程中重新组织时。这种抗原对应于最近克隆的血小板 - 内皮四跨膜抗原CD151/PETA - 3（血小板 - 内皮四跨膜抗原 - 3），并且在EC细胞 - 细胞接触位点持续被检测到。除了CD151/PETA - 3，四跨膜超家族的另外两个成员CD9和CD81/TAPA - 1（抗增殖抗体 - 1的靶点）也定位于内皮细胞间连接处。生化分析表明四跨膜分子自身之间以及CD151/PETA - 3和CD9与α3β1整合素之间存在分子关联。有趣的是，针对CD151/PETA - 3和CD81/TAPA - 1的单克隆抗体以及α3整合素特异性单克隆抗体能够在伤口愈合过程中抑制内皮细胞的迁移。通过定量延时视频显微镜研究确定，CD151/PETA - 3和CD81/TAPA - 1的结合抑制了单个内皮细胞的运动。此外，针对CD151/PETA - 3分子的单克隆抗体降低了内皮细胞侵入胶原凝胶的速率。此外，这些单克隆抗体能够增加内皮细胞与细胞外基质蛋白的粘附。这些结果共同表明，CD81/TAPA - 1和CD151/PETA - 3四跨膜分子是内皮细胞侧面连接的组成成分，它们直接或通过调节相关整合素异二聚体的功能参与细胞运动的调节。
