Department of Physics, University of Maryland, College Park, Maryland, USA.
Biophys J. 2012 Apr 4;102(7):1524-33. doi: 10.1016/j.bpj.2012.02.015. Epub 2012 Apr 3.
The morphology and duration of contacts between cells and adhesive surfaces play a key role in several biological processes, such as cell migration, cell differentiation, and the immune response. The interaction of receptors on the cell membrane with ligands on the adhesive surface leads to triggering of signaling pathways, which allow cytoskeletal rearrangement, and large-scale deformation of the cell membrane, which allows the cell to spread over the substrate. Despite numerous studies of cell spreading, the nanometer-scale dynamics of the membrane during formation of contacts, spreading, and initiation of signaling are not well understood. Using interference reflection microscopy, we study the kinetics of cell spreading at the micron scale, as well as the topography and fluctuations of the membrane at the nanometer scale during spreading of Jurkat T cells on antibody-coated substrates. We observed two modes of spreading, which were characterized by dramatic differences in membrane dynamics and topography. Formation of signaling clusters was closely related to the movement and morphology of the membrane in contact with the activating surface. Our results suggest that cell membrane morphology may be a critical constraint on signaling at the cell-substrate interface.
细胞与黏附表面之间的接触形态和持续时间在多个生物学过程中起着关键作用，例如细胞迁移、细胞分化和免疫反应。细胞膜上的受体与黏附表面上的配体相互作用，导致信号通路的触发，从而允许细胞骨架重排和细胞膜的大规模变形，使细胞能够在基底上扩展。尽管对细胞扩展进行了大量研究，但在接触形成、扩展和信号起始过程中膜的纳米级动力学仍未得到很好的理解。我们使用干涉反射显微镜研究微米尺度上的细胞扩展动力学，以及 Jurkat T 细胞在抗体包被的基底上扩展时纳米尺度上的膜形貌和涨落。我们观察到两种扩展模式，它们的膜动力学和形貌有显著差异。信号簇的形成与与激活表面接触的膜的运动和形态密切相关。我们的结果表明，细胞膜形态可能是细胞-基底界面信号的关键限制因素。
