Origin of the phagocytic respiratory burst and its role in gut epithelial phagocytosis in a basal chordate.
Origin of the phagocytic respiratory burst and its role in gut epithelial phagocytosis in a basal chordate.
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DOI：
10.1016/j.freeradbiomed.2014.02.007
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发表时间：
2014-05
影响因子：
7.4
通讯作者：
Ping Yang;Shengfeng Huang;Xinyu Yan;Guangrui Huang;Xiangru Dong;Tingting Zheng;Dongjuan Yuan;Ruihua Wang;Rui Li;Y. Tan;A. Xu
中科院分区：
文献类型：
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作者：
Ping Yang;Shengfeng Huang;Xinyu Yan;Guangrui Huang;Xiangru Dong;Tingting Zheng;Dongjuan Yuan;Ruihua Wang;Rui Li;Y. Tan;A. Xu
脊椎动物吞噬呼吸爆发（PRB）是一种高度特异性且有效的活性氧（ROS）产生机制。该机制由 NADPH 氧化酶 2 (NOX2) 介导，并被脊椎动物吞噬白细胞用来破坏内化的微生物。在这里，我们证明了 PRB 在基础脊索动物文昌鱼文昌鱼（Branchiostoma belcheri tsingtauense，bbt）中的存在。我们发现，使用抗氧化剂 NAC 来清除 ROS 的产生显着降低了受感染文昌鱼的存活率，这表明 ROS 对于有效的抗菌反应是不可或缺的。文昌鱼的 NOX 酶和胞质因子被发现共存于鳃、肠和肝盲肠的上皮细胞中，并且在暴露于微生物病原体后可能会上调。上皮细胞裂解物中ROS的产生可以通过补充重组胞质因子来重建，包括bbt-p47phox、bbt-p67phox、bbt-p47phox和bbt-Rac；恢复的 ROS 产生可以被抗 bbt-NOX2 和抗 bbt-p67phox 抗体抑制。我们还发现文昌鱼的肠道上皮衬里细胞具有细菌吞噬作用，并且有证据表明 PRB 机制可以参与该吞噬过程的启动。总之，我们报告了非脊椎动物中经典 PRB 机制的存在，并为 PRB 在上皮细胞免疫和吞噬作用中可能发挥的作用提供了第一个证据。
The vertebrate phagocytic respiratory burst (PRB) is a highly specific and efficient mechanism for reactive oxygen species (ROS) production. This mechanism is mediated by NADPH oxidase 2 (NOX2) and used by vertebrate phagocytic leukocytes to destroy internalized microbes. Here we demonstrate the presence of the PRB in a basal chordate, the amphioxusBranchiostoma belcheri tsingtauense(bbt). We show that using the antioxidant NAC to scavenge the production of ROS significantly decreased the survival rates of infected amphioxus, indicating that ROS are indispensable for efficient antibacterial responses. Amphioxus NOX enzymes and cytosolic factors were found to colocalize in the epithelial cells of the gill, intestine, and hepatic cecum and could be upregulated after exposure to microbial pathogens. The ROS production in epithelial cell lysates could be reconstructed by supplementing recombinant cytosolic factors, including bbt-p47phox, bbt-p67phox, bbt-p47phox, and bbt-Rac; the restored ROS production could be inhibited by anti-bbt-NOX2 and anti-bbt-p67phox antibodies. We also reveal that the gut epithelial lining cells of the amphioxus are competent at bacterial phagocytosis, and there is evidence that the PRB machinery could participate in the initiation of this phagocytic process. In conclusion, we report the presence of the classical PRB machinery in nonvertebrates and provide the first evidence for the possible role of PRB in epithelial cell immunity and phagocytosis.