BioMEMS Resource Center, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Shriners Burns Hospital, Boston, MA, USA.
Department of Physiology and Biophysics, University of Calgary, Calgary, Alberta, Canada.
Nat Commun. 2020 May 13;11(1):2385. doi: 10.1038/s41467-020-15476-6.
Upon tissue injury or microbial invasion, a large number of neutrophils converge from blood to the sites of injury or infection in a short time. The migration through a limited number of paths through tissues and capillary networks seems efficient and 'traffic jams' are generally avoided. However, the mechanisms that guide efficient trafficking of large numbers of neutrophils through capillary networks are not well understood. Here we show that pairs of neutrophils arriving closely one after another at capillary bifurcations migrate to alternating branches in vivo and in vitro. Perturbation of chemoattractant gradients and the increased hydraulic resistance induced by the first neutrophil in one branch biases the migration of the following neutrophil towards the other branch. These mechanisms guide neutrophils to efficiently navigate through capillary networks and outline the effect of inter-neutrophil interactions during migration on overall lymphocyte trafficking patterns in confined environments.
在组织损伤或微生物入侵时，大量中性粒细胞会在短时间内从血液中汇集到损伤或感染部位。它们穿过组织和毛细血管网络中的有限路径进行迁移，这种方式似乎很高效，并且通常可以避免“交通堵塞”。然而，引导大量中性粒细胞高效穿过毛细血管网络的机制尚未得到很好的理解。在这里，我们发现，在毛细血管分叉处紧密排列的成对中性粒细胞在体内和体外都会迁移到交替的分支中。趋化因子梯度的扰动以及第一个中性粒细胞在一个分支中产生的增加的水力阻力会使后续中性粒细胞的迁移偏向另一个分支。这些机制指导中性粒细胞有效地穿过毛细血管网络，并概述了迁移过程中中性粒细胞之间相互作用对受限环境中整体淋巴细胞迁移模式的影响。
