Katherine Z Sanidad, Stephanie L Rager, Hannah C Carrow, Aparna Ananthanarayanan, Ryann Callaghan, Lucy R Hart, Tingting Li, Purnima Ravisankar, Julia A Brown, Mohammed Amir, Jenny C Jin, Alexandria Rose Savage, Ryan Luo, Florencia Mardorsky Rowdo, M Laura Martin, Randi B Silver, Chun-Jun Guo, Jan Krumsiek, Naohiro Inohara, Melody Y Zeng
The gut microbiota promotes immune system development in early life, but the interactions between the gut metabolome and immune cells in the neonatal gut remain largely undefined. Here, we demonstrate that the neonatal gut is uniquely enriched with neurotransmitters, including serotonin, and that specific gut bacteria directly produce serotonin while down-regulating monoamine oxidase A to limit serotonin breakdown. We found that serotonin directly signals to T cells to increase intracellular indole-3-acetaldehdye and inhibit mTOR activation, thereby promoting the differentiation of regulatory T cells, both ex vivo and in vivo in the neonatal intestine...
March 15, 2024: Science Immunology