Anoctamin 6 mediates effects essential for innate immunity downstream of P2X7 receptors in macrophages

• Published in: Nature communications 2015-02, Vol.6 (1), p.6245-6245, Article 6245
• Main Authors: Ousingsawat, Jiraporn, Wanitchakool, Podchanart, Kmit, Arthur, Romao, Ana M., Jantarajit, Walailak, Schreiber, Rainer, Kunzelmann, Karl
• Format: Article
• Language: English
• Subjects: 13/106; 13/109; 13/2; 13/95; 631/250/2504/342; 631/250/262; 631/57/2270; 631/80/86; 82; 82/1; 82/51; 9/74; Animals; Anoctamins; Apoptosis - genetics; Apoptosis - immunology; Calcium - metabolism; Cell Movement; Cell Size; Gene Expression Regulation; Humanities and Social Sciences; Humans; Immunity, Innate; Ion Transport; Macrophage Activation; Macrophages - cytology; Macrophages - immunology; Mice; Mice, Knockout; multidisciplinary; Oocytes - cytology; Oocytes - metabolism; Patch-Clamp Techniques; Phagocytosis - genetics; Phospholipid Transfer Proteins - antagonists & inhibitors; Phospholipid Transfer Proteins - deficiency; Phospholipid Transfer Proteins - genetics; Phospholipid Transfer Proteins - immunology; Receptors, Purinergic P2X7 - genetics; Receptors, Purinergic P2X7 - immunology; RNA, Small Interfering - genetics; RNA, Small Interfering - metabolism; Science; Science (multidisciplinary); Signal Transduction; Xenopus laevis
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms7245

Purinergic P2X 7 receptors (P2X 7 R) are fundamental to innate immune response. In macrophages, transient stimulation of P2X 7 R activates several transport mechanisms and induces the scrambling of phospholipids with subsequent membrane blebbing and apoptosis. These processes support phagocytosis and subsequent killing of phagocytosed bacteria. Here we demonstrate that the stimulation of P2X 7 receptors activates anoctamin 6 (ANO6, TMEM16F), a protein that functions as Ca 2+ dependent phospholipid scramblase and Ca 2+ -activated Cl − channel. Inhibition or knockdown of ANO6 attenuates ATP-induced cell shrinkage, cell migration and phospholipid scrambling. In mouse macrophages, Ano6 produces large ion currents by stimulation of P2X 7 receptors and contributes to ATP-induced membrane blebbing and apoptosis, which is largely reduced in macrophages from Ano6 −/− mice. ANO6 supports bacterial phagocytosis and killing by mouse and human THP-1 macrophages. Our data demonstrate that anoctamin 6 is an essential component of the immune defense by macrophages. Activation of purinergic P2X 7 receptors is important for phagocytosis and bacterial killing. Here the authors show that a phospholipid scramblase, Anoctamin 6, is activated downstream of P2X 7 R and is a critical mediator of bacterial internalization and killing by macrophages.