Platt Nick, Fineran Paul
Department of Pharmacology, University of Oxford, Oxford, UK.
Methods Cell Biol. 2015;126:287-304. doi: 10.1016/bs.mcb.2014.10.025. Epub 2015 Jan 14.
Phagocytosis is a critical biological activity through which the host can protect itself from infectious and non-infectious environmental particles and remove unwanted host cells in order to maintain tissue homeostasis. Phagocytosis is an ancient, conserved process that is apparent in all multicellular organisms. The process of phagocytosis requires the recognition of ligands on particles by specific receptors expressed by the phagocyte that promote internalization via reorganization of cytoskeletal elements and directed formation of the phagosome. Subsequent phagosome-lysosome fusion delivers the contents for destruction and recycling in the acidic compartment. Significantly, receptor engagement and uptake can also trigger intracellular signaling pathways that initiate appropriate innate immune and pro-inflammatory or anti-inflammatory responses dependent upon the nature of the particle. The important benefits of phagocytosis to host survival are exemplified by the detrimental effects to health that occur when phagocytic efficiency is diminished. In an overview, we discuss the different experimental approaches or options that can be considered when investigating and determining the characteristics and quantification of phagocytic activity. These criteria will include choice of phagocytic cell type, selection, and method of labeling of particle for monitoring internalization, targeting of particles to specific receptors, and quantification of ingestion either at the single cell or at the population level. We provide two detailed examples of phagocytosis assays.
吞噬作用是一种关键的生物学活动，通过该活动宿主可以保护自身免受传染性和非传染性环境颗粒的侵害，并清除不需要的宿主细胞，以维持组织稳态。吞噬作用是一个古老且保守的过程，在所有多细胞生物中都很明显。吞噬作用的过程需要吞噬细胞表达的特定受体识别颗粒上的配体，通过细胞骨架元件的重组促进内化并引导吞噬体的形成。随后吞噬体与溶酶体融合，将内容物输送到酸性区室进行破坏和再循环。值得注意的是，受体结合和摄取还可以触发细胞内信号通路，根据颗粒的性质引发适当的先天免疫和促炎或抗炎反应。吞噬效率降低时对健康产生的有害影响例证了吞噬作用对宿主生存的重要益处。在概述中，我们讨论了在研究和确定吞噬活性的特征和定量时可以考虑的不同实验方法或选项。这些标准将包括吞噬细胞类型的选择、颗粒标记的选择和用于监测内化的方法、颗粒靶向特定受体以及在单细胞或群体水平上对摄取的定量。我们提供了两个吞噬作用测定的详细示例。
