Eukaryotic cells migrate by coupling the intracellular force of the actin cytoskeleton to the environment. While force coupling is usually mediated by transmembrane adhesion receptors, especially those of the integrin family, amoeboid cells such as leukocytes can migrate extremely fast despite very low adhesive forces 1 . Here we show that leukocytes cannot only migrate under low adhesion but can also transmit forces in the complete absence of transmembrane force coupling. When confined within three-dimensional environments, they use the topographical features of the substrate to propel themselves. Here the retrograde flow of the actin cytoskeleton follows the texture of the substrate, creating retrograde shear forces that are sufficient to drive the cell body forwards. Notably, adhesion-dependent and adhesion-independent migration are not mutually exclusive, but rather are variants of the same principle of coupling retrograde actin flow to the environment and thus can potentially operate interchangeably and simultaneously. As adhesion-free migration is independent of the chemical composition of the environment, it renders cells completely autonomous in their locomotive behaviour. Within three-dimensional environments, leukocytes can migrate even in the complete absence of adhesive forces using the topographical features of the substrate to propel themselves.

中文翻译：

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使用环境地形的细胞运动

真核细胞通过将肌动蛋白细胞骨架的细胞内力与环境耦合而迁移。虽然力耦合通常是由跨膜粘附受体介导的，尤其是那些整合素家族，但尽管粘附力非常低 1 ，但白细胞等变形虫细胞可以非常快速地迁移。在这里，我们表明白细胞不仅可以在低粘附力下迁移，而且还可以在完全没有跨膜力耦合的情况下传递力。当被限制在三维环境中时，它们会利用基板的地形特征来推动自己。在这里，肌动蛋白细胞骨架的逆行流动跟随底物的质地，产生足以驱动细胞体向前移动的逆行剪切力。尤其，依赖粘附和不依赖粘附的迁移并不相互排斥，而是将逆行肌动蛋白流与环境耦合的相同原理的变体，因此可以潜在地互换和同时操作。由于无粘附迁移独立于环境的化学成分，它使细胞在其运动行为中完全自主。在三维环境中，即使在完全没有粘附力的情况下，白细胞也可以利用基板的地形特征来移动自己。由于无粘附迁移独立于环境的化学成分，它使细胞在其运动行为中完全自主。在三维环境中，即使在完全没有粘附力的情况下，白细胞也可以利用基板的地形特征来移动自己。由于无粘附迁移独立于环境的化学成分，它使细胞在其运动行为中完全自主。在三维环境中，即使在完全没有粘附力的情况下，白细胞也可以利用基板的地形特征来移动自己。