Swetman Andersen Claire A, Handley Matthew, Pollara Gabriel, Ridley Anne J, Katz David R, Chain Benjamin M
Department of Immunology and Molecular Pathology, University College London, Windeyer Building, 46 Cleveland Street, London W1T 4JF, UK.
Int Immunol. 2006 Aug;18(8):1295-303. doi: 10.1093/intimm/dxl062. Epub 2006 Jun 28.
The morphology of antigen-presenting dendritic cells (DCs) is characterized by the presence of numerous long dendrites. The formation of these processes is shown to require the interaction between the beta1-integrin (CD29) on the surface of the DCs and fibronectin in the extracellular matrix. This interaction occurs at focal contacts formed at the tips of dendrites, which contain high concentrations of the beta1-integrins, actin and the cytoskeletal proteins vinculin, paxillin and talin. Dendrites contain an extensive microtubule (MT) network, and are retracted in the presence of the MT inhibitor colchicine, suggesting that MTs are essential for dendrite stability. The dendritic morphology is shown to contribute directly to an enhanced ability to capture dendritic cell specific ICAM-3 grabbing nonintegrin (DC-SIGN)-coated beads. Time-lapse photography demonstrates that dendrites are highly dynamic structures, with cells extending and retracting multiple dendrites in different directions over a 3-h period. This motility increases the area scanned by an individual DC by over 2-fold. The unusual combination of a dendritic morphology and high motility is likely to play a major role in the efficient function of DCs as sentinels of the immune system.
抗原呈递树突状细胞（DCs）的形态特征是存在众多长树突。这些突起的形成表明需要DCs表面的β1整合素（CD29）与细胞外基质中的纤连蛋白之间的相互作用。这种相互作用发生在树突尖端形成的粘着斑处，粘着斑含有高浓度的β1整合素、肌动蛋白以及细胞骨架蛋白纽蛋白、桩蛋白和踝蛋白。树突含有广泛的微管（MT）网络，并且在MT抑制剂秋水仙碱存在的情况下会缩回，这表明微管对于树突的稳定性至关重要。树突形态显示直接有助于增强捕获树突状细胞特异性ICAM-3结合非整合素（DC-SIGN）包被珠子的能力。延时摄影表明树突是高度动态的结构，细胞在3小时内会向不同方向伸出和缩回多个树突。这种运动性使单个DC扫描的面积增加了两倍多。树突形态与高运动性的这种异常组合可能在DCs作为免疫系统哨兵的高效功能中起主要作用。
