Research and Education Center for Physics of Solid State Nanostructures, National Research Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia.
Department of Nanotechnology and biotechnology, R.E. Alekseev Nizhny Novgorod Technical University, Nizhny Novgorod, Russia.
J Mol Recognit. 2018 Jul;31(7):e2707. doi: 10.1002/jmr.2707. Epub 2018 Mar 23.
In the process of performing their protective functions, neutrophils can form neutrophil extracellular traps (NETs), consisting of DNA in combination with enzymes and histones. The aim of the study was to determine the dynamics of the formation of NETs under the influence of opsonized Staphylococcus aureus and to determine the morphological features of their development in real time by atomic force microscopy. It was found that the maximum formation of NETs was observed after 3 hours of co-incubation of neutrophils and opsonized S. aureus. For the first time, the atomic force microscopy method revealed that, at first, large blocks of parallel DNA helices are formed, which then spread in waves, and only then their bifurcation and separation can be observed. Some of the strands formed are covered by a shell, which subsequently completely disappears. Enzymes and histones become clearly visible only after 140 to 150 minutes of observation. The DNA helixes move toward the opsonized S. aureus. After NET formation, the cell remains on the substrate only in the form of traces of focal adhesion. This, and the fact that the maximum amount of NETs is formed after 3 hours of co-incubation with opsonized S. aureus, suggests that the formation of NETs follows the classical mechanism. The study of the dynamics of formation and the microstructure of NETs makes it possible to estimate the time frame for the implementation of this protective mechanism of the human body when performing the compensatory inflammatory reaction.
在执行其保护功能的过程中，中性粒细胞可以形成由 DNA 与酶和组蛋白结合而成的中性粒细胞细胞外陷阱 (NETs)。本研究的目的是确定受调理的金黄色葡萄球菌影响下 NETs 形成的动力学，并通过原子力显微镜实时确定其发展的形态特征。结果发现，中性粒细胞与调理后的金黄色葡萄球菌共同孵育 3 小时后，NETs 的形成达到最大值。首次通过原子力显微镜法发现，最初形成的是大的平行 DNA 螺旋块，然后呈波状展开，之后才观察到其分叉和分离。形成的一些链被外壳覆盖，随后外壳完全消失。只有在观察 140 到 150 分钟后，酶和组蛋白才变得清晰可见。DNA 螺旋向调理后的金黄色葡萄球菌移动。NET 形成后，细胞仅以焦点黏附痕迹的形式留在基质上。这一事实以及与调理后的金黄色葡萄球菌共同孵育 3 小时后形成的 NETs 最多，表明 NETs 的形成遵循经典机制。对形成动力学和 NETs 微观结构的研究可以估计人体在执行代偿性炎症反应时实施这种保护机制的时间框架。
