Mohamed Ibrahem Elhawy, Noran Abdel Wadood, Maria Grammer, Paula Betzold, Emely Herrmann, Giuseppina Sole Lanzilli, Firat Biradli, Caroline Klozenbücher, Andreas Klein, Nosaibah Alakkam, Monika I Hollenhorst, Kiana Gaini-Rahimi, Saskia B Evers, Soumya Kusumakshi, Amanda Wyatt, Andreas M Kany, Sören L Becker, Markus Bischoff, Veit Flockerzi, Thomas Gudermann, Vladimir Chubanov, Martin Empting, Anna K H Hirsch, Christoph Schneider, Ulrich Boehm, Gabriela Krasteva-Christ
Tuft cells (TCs) act as crucial airway sentinels that detect bacterial metabolites and initiate immune responses, yet the underlying mechanisms remain poorly understood. Here, we identify tracheal TCs as the initial source of leukotrienes (LTs), released during bacterial infection. Tracheal TCs discriminate pathogenic from commensal bacteria by sensing extracellular ATP (eATP) released by pathogens, including Pseudomonas aeruginosa and Rodentibacter pneumotropicus, within 4 h of infection, through the transient receptor potential cation channel subfamily M member 5 (Trpm5). This induces the LT release, including LTB4, and promotes rapid recruitment of neutrophils and macrophages to the trachea and alveolar spaces. Trpm5-/- mice failed to detect bacterial eATP, exhibited neutrophil sequestration in the spleen, and became colonized following R. pneumotropicus infection, while Trpm5+/+ mice efficiently cleared the pathogen. These findings uncover a critical TC-dependent sensing mechanism in pneumonia, establishing TCs as both ATP sensors and triggers of acute innate immune responses.