Departments of Microbiology and Immunology, Genetics and Medicine, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, USA.
Immunol Rev. 2016 Sep;273(1):219-31. doi: 10.1111/imr.12438.
Phagocytes, such as neutrophils and macrophages, engulf microbes into phagosomes and launch chemical attacks to kill and degrade them. Such a critical innate immune function necessitates ion participation. Chloride, the most abundant anion in the human body, is an indispensable constituent of the myeloperoxidase (MPO)-H2 O2 -halide system that produces the potent microbicide hypochlorous acid (HOCl). It also serves as a balancing ion to set membrane potentials, optimize cytosolic and phagosomal pH, and regulate phagosomal enzymatic activities. Deficient supply of this anion to or defective attainment of this anion by phagocytes is linked to innate immune defects. However, how phagocytes acquire chloride from their residing environment especially when they are deployed to epithelium-lined lumens, and how chloride is intracellularly transported to phagosomes remain largely unknown. This review article will provide an overview of chloride protein carriers, potential mechanisms for phagocytic chloride preservation and acquisition, intracellular chloride supply to phagosomes for oxidant production, and methods to measure chloride levels in phagocytes and their phagosomes.
吞噬细胞，如中性粒细胞和巨噬细胞，将微生物吞噬到吞噬体中，并发动化学攻击以杀死和降解它们。这种关键的先天免疫功能需要离子参与。氯离子是人体中最丰富的阴离子，是髓过氧化物酶 (MPO)-H2O2-卤化物系统的不可或缺组成部分，该系统产生有效的杀菌剂次氯酸 (HOCl)。它还作为平衡离子来设置膜电位、优化细胞质和吞噬体 pH 值，并调节吞噬体酶活性。吞噬细胞中这种阴离子的供应不足或无法获得这种阴离子与先天免疫缺陷有关。然而，吞噬细胞如何从其居住环境中获取氯离子，特别是当它们被部署到衬有上皮的腔道时，以及氯离子如何被细胞内运输到吞噬体以产生氧化剂，这些仍然在很大程度上是未知的。本文综述了氯离子蛋白载体、吞噬细胞中氯离子的保存和摄取的潜在机制、为氧化生成提供到吞噬体的细胞内氯离子供应，以及测量吞噬细胞及其吞噬体中氯离子水平的方法。
