Giorgia Renga, Fiorella D'Onofrio, Marilena Pariano, Roberta Galarini, Carolina Barola, Claudia Stincardini, Marina M Bellet, Helmut Ellemunter, Cornelia Lass-Flörl, Claudio Costantini, Valerio Napolioni, Allison K Ehrlich, Cinzia Antognelli, Massimo Fini, Enrico Garaci, Emilia Nunzi, Luigina Romani
The aromatic amino acid L-tryptophan (Trp) is essentially metabolized along the host and microbial pathways. While much is known about the role played by downstream metabolites of each pathways in intestinal homeostasis, their role in lung immune homeostasis is underappreciated. Here we have examined the role played by the Trp hydroxylase/5-hydroxytryptamine (5-HT) pathway in calibrating host and microbial Trp metabolism during Aspergillus fumigatus pneumonia. We found that 5-HT produced by mast cells essentially contributed to pathogen clearance and immune homeostasis in infection by promoting the host protective indoleamine-2,3-dioxygenase 1/kynurenine pathway and limiting the microbial activation of the indole/aryl hydrocarbon receptor pathway...
September 16, 2023: Nature Communications