Syntaxin-2 balances phagocytic uptake and phagolysosomal clearance in macrophages.

阅读:11
作者:Samanta Suman, Nandi Abhrajyoti, Datta Rupak, Dolai Subhankar
Phagocytosis engulfs receptor-bound particles within phagosomes that mature into acidic, hydrolase-enriched phagolysosomes for content degradation. Although an essential process for host defense and homeostasis, defective or uncontrolled phagocytosis can be detrimental. We report here, that syntaxin-2 (Stx2), a poorly characterized SNARE in phagocytes, defines the course of macrophage phagocytosis by coordinating surface receptor density, phagosome biogenesis and maturation. Stx2 is expressed primarily on the plasma membrane, early endosomes and phagosomes. Stx2 knockdown (Stx2-KD) increases entrapment and uptake of IgG-opsonized particles owing to dysregulated formation and expansion of phagocytic cups driven by elevated IgG receptor recycling and trafficking of early endosomes and VAMP4-positive post-Golgi compartments to phagocytic cups. Interestingly, Stx2-KD decreases secretion of pro-cathepsins and increases lysosome content. However, Stx2-KD impedes phagosome maturation by preventing coalescence with late endosomes, lysosomes and reducing phagosomal acidification. Consequently, Stx2-depleted macrophages exhibit aberrant uptake of IgG-opsonized bacteria and impaired digestion, resulting in increased intracellular accumulation of intact bacteria. Collectively, Stx2 critically balances phagocytic uptake and phagolysosomal clearance in macrophages, suggesting that Stx2 could be an attractive target to modulate phagocytosis plasticity and to control aberrant phagocytosis.

特别声明

1、本文转载旨在传播信息,不代表本网站观点,亦不对其内容的真实性承担责任。

2、其他媒体、网站或个人若从本网站转载使用,必须保留本网站注明的“来源”,并自行承担包括版权在内的相关法律责任。

3、如作者不希望本文被转载,或需洽谈转载稿费等事宜,请及时与本网站联系。

4、此外,如需投稿,也可通过邮箱info@biocloudy.com与我们取得联系。