Program in Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada.
Immunol Rev. 2014 Nov;262(1):193-215. doi: 10.1111/imr.12212.
Phagocytosis is a remarkably complex and versatile process: it contributes to innate immunity through the ingestion and elimination of pathogens, while also being central to tissue homeostasis and remodeling by clearing effete cells. The ability of phagocytes to perform such diverse functions rests, in large part, on their vast repertoire of receptors. In this review, we address the various receptor types, their mobility in the plane of the membrane, and two modes of receptor crosstalk: priming and synergy. A major section is devoted to the actin cytoskeleton, which not only governs receptor mobility and clustering but also is instrumental in particle engulfment. Four stages of the actin remodeling process are identified and discussed: (i) the 'resting' stage that precedes receptor engagement, (ii) the disruption of the cortical actin prior to formation of the phagocytic cup, (iii) the actin polymerization that propels pseudopod extension, and (iv) the termination of polymerization and removal of preassembled actin that are required for focal delivery of endomembranes and phagosomal sealing. These topics are viewed in the larger context of the differentiation and polarization of the phagocytic cells.
它通过吞噬和消除病原体来促进先天免疫，同时通过清除衰老细胞来维持组织内稳态和重塑。吞噬细胞能够执行如此多样化的功能，在很大程度上依赖于它们广泛的受体库。在这篇综述中，我们将讨论各种受体类型、它们在膜平面上的流动性以及两种受体串扰模式：启动和协同作用。一个主要部分专门讨论肌动蛋白细胞骨架，它不仅控制受体的流动性和聚集，而且在颗粒吞噬中也起着重要作用。确定并讨论了肌动蛋白重塑过程的四个阶段：(i) 受体结合前的“静止”阶段，(ii) 在吞噬小泡形成之前皮质肌动蛋白的破坏，(iii) 推动伪足延伸的肌动蛋白聚合，以及 (iv) 聚合的终止和预先组装的肌动蛋白的去除，这对于内体膜和吞噬体封闭的焦点传递是必需的。这些主题是在吞噬细胞的分化和极化的更大背景下进行讨论的。
