Chang C C, Lieberman S M, Moghe P V
Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, NJ 08854-8058, USA.
Biomaterials. 1999 Feb;20(3):273-81. doi: 10.1016/s0142-9612(98)00171-9.
Chemoattractant-induced phenomena of polarity and migration of polymorphonuclear leukocytes (PMN) are believed to play a key physiological role in controlling bacterial infections on implantable vascular biomaterials. Our study targeted the spreading behavior of human PMN adherent to expanded polytetrafluoroethylene (ePTFE), pretreated with various plasma proteins, in response to the chemoattractant, N-formyl-methionyl-leucyl-phenylalanine (fMLP). To this end, a novel imaging configuration was developed to allow in situ reconstructive analysis of PMN 3-D morphology on opaque ePTFE surfaces, using optical sectioning confocal microscopy. Following fMLP stimulation, PMN morphological polarity was enhanced on all substrates studied except fibrinogen treated ePTFE. 3-D PMN morphometry revealed that in the absence of fMLP, overall cell spreading was minimized on albumin-treated ePTFE and maximized on fibrinogen and immunoglobulin-G-treated ePTFE. Following fMLP stimulation, overall PMN spreading increased markedly on untreated and albumin-coated ePTFE, while it stayed invariant on IgG and plasma treated ePTFE, and decreased on fibrinogen-treated ePTFE. Spatial analysis of PMN spreading following fMLP stimulation revealed enhanced PMN attachment on untreated and albumin treated ePTFE and diminished attachment on fibrinogen and plasma treated ePTFE. Thus, chemoattractant stimulation altered a wide range of PMN spreading attributes on ePTFE, including morphological polarity, substrate attachment, and 3-D membrane spreading, in a substrate dependent manner. These chemoattractant-induced spreading responses may also have important consequences for PMN phagocytosis. We report that fMLP stimulation led to enhanced unopsonized particulate phagocytosis on untreated and albumin treated ePTFE, but caused no discernible change in phagocytosis on other protein substrates. Thus, chemoattractant modulation of PMN spreading on ePTFE is highly substrate-regulated, and manifests in concerted effects on PMN phagocytosis.
趋化因子诱导的多形核白细胞（PMN）极性和迁移现象被认为在控制可植入血管生物材料上的细菌感染中发挥关键生理作用。我们的研究目标是，研究经各种血浆蛋白预处理的人PMN在趋化因子N-甲酰甲硫氨酰-亮氨酰-苯丙氨酸（fMLP）作用下，黏附于膨体聚四氟乙烯（ePTFE）上的铺展行为。为此，开发了一种新颖的成像配置，使用光学切片共聚焦显微镜对不透明ePTFE表面上的PMN三维形态进行原位重建分析。在fMLP刺激后，除了纤维蛋白原处理的ePTFE外，在所研究的所有底物上PMN的形态极性均增强。三维PMN形态测量显示，在没有fMLP的情况下，白蛋白处理的ePTFE上的整体细胞铺展最小，而在纤维蛋白原和免疫球蛋白G处理的ePTFE上最大。在fMLP刺激后，未处理和白蛋白包被的ePTFE上的整体PMN铺展显著增加，而在IgG和血浆处理的ePTFE上保持不变，在纤维蛋白原处理的ePTFE上则减少。fMLP刺激后PMN铺展的空间分析显示，未处理和白蛋白处理的ePTFE上PMN的附着增强，而在纤维蛋白原和血浆处理的ePTFE上附着减少。因此，趋化因子刺激以底物依赖的方式改变了ePTFE上PMN铺展的多种属性，包括形态极性、底物附着和三维膜铺展。这些趋化因子诱导的铺展反应可能对PMN吞噬作用也有重要影响。我们报告称，fMLP刺激导致未处理和白蛋白处理的ePTFE上未调理颗粒的吞噬作用增强，但在其他蛋白质底物上的吞噬作用没有明显变化。因此，趋化因子对PMN在ePTFE上铺展的调节高度依赖底物，并对PMN吞噬作用产生协同效应。
