The surface of mammalian cells offers an interface between the cell interior and its surrounding milieu. As part of the innate immune system, macrophages have cell surface features optimised for probing and sampling as they patrol our tissues for pathogens, debris or dead cells. Their highly dynamic and constantly moving cell surface has extensions such as lamellipodia, filopodia and dorsal ruffles that help detect pathogens. Dorsal ruffles give rise to macropinosomes for rapid, high volume non-selective fluid sampling, receptor internalisation and plasma membrane turnover. Ruffles can also generate phagocytic cups for the receptor-mediated uptake of pathogens or particles. The membrane lipids, actin cytoskeleton, receptors and signalling proteins that constitute these cell surface domains are discussed. Although the cell surface is designed to counteract pathogens, many bacteria, viruses and other pathogens have evolved to circumvent or hijack these cell structures and their underlying machinery for entry and survival. Nevertheless, these features offer important potential for developing vaccines, drugs and preventative measures to help fight infection.

中文翻译：

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病原体识别和进入的细胞表面环境。

哺乳动物细胞的表面提供了细胞内部与其周围环境之间的界面。作为先天免疫系统的一部分，巨噬细胞具有针对探测和采样而优化的细胞表面特征，因为它们在我们的组织中巡逻以寻找病原体、碎片或死细胞。它们高度动态且不断移动的细胞表面具有片状伪足、丝状伪足和背侧褶边等延伸，有助于检测病原体。背侧皱褶产生巨胞质体，用于快速、大容量非选择性液体取样、受体内化和质膜周转。褶边还可以产生吞噬杯，用于受体介导的病原体或颗粒的摄取。讨论了构成这些细胞表面结构域的膜脂、肌动蛋白细胞骨架、受体和信号蛋白。尽管细胞表面的设计目的是对抗病原体，但许多细菌、病毒和其他病原体已经进化到规避或劫持这些细胞结构及其进入和生存的基本机制。尽管如此，这些特征为开发疫苗、药物和预防措施以帮助对抗感染提供了重要潜力。