Endothelial cells proactively form microvilli-like membrane projections upon intercellular adhesion molecule I engagement of leukocyte LFA-1
Endothelial cells proactively form microvilli-like membrane projections upon intercellular adhesion molecule I engagement of leukocyte LFA-1
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DOI：
10.4049/jimmunol.171.11.6135
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发表时间：
2003-12-01
影响因子：
4.4
通讯作者：
Springer, TA
中科院分区：
文献类型：
--
作者：
Carman, CV;Jun, CD;Springer, TA
特异性白细胞/内皮细胞相互作用对免疫和炎症至关重要，但这种相互作用界面的分子细节仍然知之甚少。因此，我们调查，与共聚焦显微镜，在这种情况下，中央粘附分子ICAM-1和LFA-1的分布动力学。使用荧光抗ICAM-1 Fab染色的活化HUVEC单层或表达ICAM-1-绿色荧光蛋白的中国仓鼠卵巢-K1细胞与携带LFA-1的单核细胞、嗜中性粒细胞或K562 LFA-1转染子结合。ICAM-1迅速重新定位到新形成的微绒毛样膜的预测响应结合LFA-1的白细胞。这些富含ICAM-1的突起环绕着白细胞，并向两侧延伸，而LFA-1在下方聚集成线性轨道。投射形成独立的VCAM-1/非常晚的Ag 4相互作用，剪切，和积极的贡献，从LFA-1轴承细胞。在ICAM-1轴承内皮细胞，预测富含肌动蛋白，但不是微管，需要细胞内钙，和完整的微丝和微管细胞骨架和独立的Rho/Rho激酶信号。用细胞松弛素D、秋水仙碱或BAPTA-AM破坏这些投射对牢固的粘附没有影响。这些数据表明，响应于LFA-1的参与，内皮细胞主动形成ICAM-1富集的杯状结构，其围绕粘附的白细胞，但对于牢固的粘附并不重要。这一发现在白细胞跨内皮迁移中留下了可能的作用，这与杯状结构形成的几何形状和动力学一致。
Specific leukocyte/endothelial interactions are critical for immunity and inflammation, yet the molecular details of this interaction interface remain poorly understood. Thus, we investigated, with confocal microscopy, the distribution dynamics of the central adhesion molecules ICAM-1 and LFA-1 in this context. Monolayers of activated HUVECs stained with fluorescent anti-ICAM-1 Fabs or Chinese hamster ovary-K1 cells expressing ICAM-1-green fluorescent protein were allowed to bind LFA-1-bearing monocytes, neutrophils, or K562 LFA-1 transfectants. ICAM-1 was rapidly relocalized to newly formed microvilli-like membrane projections in response to binding LFA-1 on leukocytes. These ICAM-1-enriched projections encircled the leukocytes extending up their sides and clustered LFA-1 underneath into linear tracks. Projections formed independently of VCAM-1/very late Ag 4 interactions, shear, and proactive contributions from the LFA-1-bearing cells. In the ICAM-1-bearing endothelial cells, projections were enriched in actin but not microtubules, required intracellular calcium, and intact microfilament and microtubule cytoskeletons and were independent of Rho/Rho kinase signaling. Disruption of these projections with cytochalasin D, colchicine, or BAPTA-AM had no affect on firm adhesion. These data show that in response to LFA-1 engagement the endothelium proactively forms an ICAM-1-enriched cup-like structure that surrounds adherent leukocytes but is not important for firm adhesion. This finding leaves open a possible role in leukocyte transendothelial migration, which would be consistent with the geometry and kinetics of formation of the cup-like structure.