Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria.
Institute of Translational Medicine, Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool, UK.
Nature. 2020 Jun;582(7813):582-585. doi: 10.1038/s41586-020-2283-z. Epub 2020 May 13.
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. 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.
真核细胞通过将细胞内肌动蛋白细胞骨架的力与环境耦合来迁移。虽然力偶联通常是通过跨膜粘附受体介导的，特别是整合素家族的那些，但像白细胞这样的变形细胞尽管粘附力非常低，仍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，而且在完全没有跨膜力偶联的情况下也可以传递力。当被限制在三维环境中时，它们利用基质的形貌来推动自身。在这里，肌动蛋白细胞骨架的逆行流动遵循基质的纹理，产生足以推动细胞体向前的逆行剪切力。值得注意的是，依赖于粘附的和不依赖于粘附的迁移并不是相互排斥的，而是同一将逆行肌动蛋白流与环境耦合的原则的变体，因此它们可能可以相互交替和同时操作。由于无粘附迁移不依赖于环境的化学成分，它使细胞在其运动行为中完全自主。
