Lippert Anna H, Dimov Ivan B, Winkel Alexander K, Humphrey Jane, McColl James, Chen Kevin Y, Santos Ana M, Jenkins Edward, Franze Kristian, Davis Simon J, Klenerman David
Department of Chemistry, University of Cambridge, Cambridge, United Kingdom.
Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.
Biophys J. 2021 Jan 5;120(1):35-45. doi: 10.1016/j.bpj.2020.11.021. Epub 2020 Nov 26.
Much of what we know about the early stages of T cell activation has been obtained from studies of T cells interacting with glass-supported lipid bilayers that favor imaging but are orders of magnitude stiffer than typical cells. We developed a method for attaching lipid bilayers to polydimethylsiloxane polymer supports, producing "soft bilayers" with physiological levels of mechanical resistance (Young's modulus of 4 kPa). Comparisons of T cell behavior on soft and glass-supported bilayers revealed that whereas late stages of T cell activation are thought to be substrate-stiffness dependent, early calcium signaling was unaffected by substrate rigidity, implying that early steps in T cell receptor triggering are not mechanosensitive. The exclusion of large receptor-type phosphatases was observed on the soft bilayers, however, even though it is yet to be demonstrated at authentic cell-cell contacts. This work sets the stage for an imaging-based exploration of receptor signaling under conditions closely mimicking physiological cell-cell contact.
我们对T细胞激活早期阶段的许多了解都来自于对T细胞与玻璃支持的脂质双层相互作用的研究，这种脂质双层有利于成像，但比典型细胞硬几个数量级。我们开发了一种将脂质双层附着到聚二甲基硅氧烷聚合物支持物上的方法，生产出具有生理水平机械阻力（杨氏模量为4kPa）的“软双层”。对T细胞在软双层和玻璃支持双层上行为的比较表明，虽然T细胞激活的后期阶段被认为依赖于底物硬度，但早期钙信号不受底物刚性的影响，这意味着T细胞受体触发的早期步骤不是机械敏感的。然而，在软双层上观察到大型受体型磷酸酶被排除，尽管在真实的细胞间接触中尚未得到证实。这项工作为在紧密模拟生理细胞间接触的条件下基于成像的受体信号探索奠定了基础。
