小柯机器人

加拿大卡尔加里大学Paul Kubes和Ajitha Thanabalasuriar研究小组合作的论文发现，巡逻肺泡巨噬细胞（AMs）通过掩盖免疫系统中的细菌来维持体内平衡。2020年9月3日，《细胞》在线发表了这一成果。

研究人员研发了体内肺泡实时活体成像技术，发现AMs使用Kohn毛孔在肺泡中和肺泡间爬行。重要的是，这些巨噬细胞可以感知、趋化并高效吞噬吸入的细菌病原体，例如铜绿假单胞菌和金黄色葡萄球菌，从而使细菌不被中性粒细胞感知。AM对细菌的趋化性受损会导致多余中性粒细胞的招募，从而导致炎症和损伤。在患病情况下，甲型流感病毒感染会通过II型干扰素信号传导途径破坏AM爬行，这大大增加了继发性细菌共感染。

据悉，通过呼吸，人类每天吸入超过10,000升的非无菌空气，这使得某些病原体进入肺泡。有趣的是，肺泡的数量远超过肺泡巨噬细胞数目，这有利于缺乏AMs肺泡的形成。如果AM像大多数组织巨噬细胞一样是固定的，那么除非有来自血液嗜中性粒细胞的介入，否则病原体将利用这种数字优势。但是，这将导致全身持续性炎症的发生。

附：英文原文

Title: Patrolling Alveolar Macrophages Conceal Bacteria from the Immune System to Maintain Homeostasis

Author: Arpan Sharma Neupane, Michelle Willson, Andrew Krzysztof Chojnacki, Fernanda Vargas E Silva Castanheira, Christopher Morehouse, Agostina Carestia, Ashley Elaine Keller, Moritz Peiseler, Antonio DiGiandomenico, Margaret Mary Kelly, Matthias Amrein, Craig Jenne, Ajitha Thanabalasuriar, Paul Kubes

Issue&Volume: 2020-09-03

Abstract: During respiration, humans breathe in more than 10,000 liters of non-sterile air daily,allowing some pathogens access to alveoli. Interestingly, alveoli outnumber alveolarmacrophages (AMs), which favors alveoli devoid of AMs. If AMs, like most tissue macrophages,are sessile, then this numerical advantage would be exploited by pathogens unlessneutrophils from the blood stream intervened. However, this would translate to omnipresentpersistent inflammation. Developing in vivo real-time intravital imaging of alveoli revealed AMs crawling in and between alveoliusing the pores of Kohn. Importantly, these macrophages sensed, chemotaxed, and, withhigh efficiency, phagocytosed inhaled bacterial pathogens such as P. aeruginosa and S. aureus, cloaking the bacteria from neutrophils. Impairing AM chemotaxis toward bacteriainduced superfluous neutrophil recruitment, leading to inappropriate inflammationand injury. In a disease context, influenza A virus infection impaired AM crawlingvia the type II interferon signaling pathway, and this greatly increased secondarybacterial co-infection.

DOI: 10.1016/j.cell.2020.08.020

Source: https://www.cell.com/cell/fulltext/S0092-8674(20)31011-4