Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131, USA.
FEBS Lett. 2012 Feb 17;586(4):416-21. doi: 10.1016/j.febslet.2012.01.013. Epub 2012 Jan 18.
When mast cells contact a monovalent antigen-bearing fluid lipid bilayer, IgE-loaded FcεRI receptors aggregate at contact points and trigger degranulation and the release of immune activators. We used two-color total internal reflection fluorescence microscopy and single-particle tracking to show that most fluorescently labeled receptor complexes diffuse freely within these micron-size clusters, with a diffusion coefficient comparable to free receptors in resting cells. At later times, when the small clusters coalesce to form larger patches, receptors diffuse even more rapidly. In all cases, Monte Carlo diffusion simulations ensured that the tracking results were free of bias, and distinguished biological from statistical variation. These results show the diversity in receptor mobility in mast cells, demonstrating at least three distinct states of receptor diffusivity.
当肥大细胞接触单价抗原结合的单层脂双分子层时，IgE 负载的 FcεRI 受体在接触点聚集，并触发脱颗粒和免疫激活物的释放。我们使用双色全内反射荧光显微镜和单粒子跟踪技术表明，大多数荧光标记的受体复合物在这些微米大小的簇内自由扩散，扩散系数与静息细胞中游离受体相当。在稍后的时间里，当小簇融合形成更大的斑块时，受体的扩散速度甚至更快。在所有情况下，蒙特卡罗扩散模拟确保了跟踪结果没有偏差，并区分了生物学和统计学的变化。这些结果显示了肥大细胞中受体迁移的多样性，证明了受体扩散性至少有三种不同的状态。
