How does the organism protect itself against potential pathogenic threats associated with food intake? In their latest work, the team of Gérard Eberl and their collaborators demonstrate a crosstalk between the nervous and immune system to set up a timely activation of innate lymphoid cells (ILCs) to increase resistance of mice to helmintic or bacterial infection.
Feeding induces the abundant production of the neuropeptide Vasoactive Intestinal Peptide (VIP) by local neurons in the intestine. This study focused its investigation on the role of this neuropeptide on the mouse innate system. They show that exposure to VIP alone leads to modest activation of ILCs, but strongly potentiates ILCs to concomitant or subsequent activation by the inducer cytokines (IL-33 and IL-25 for ILC2s or IL-23 and IL-1b for ILC3s) to activate innate immunity. This synergistic activity relies on the cAMP pathway and increased glycolysis. Therefore, when faced with the actual threats, such as helminths (Trichuris muris) or bacteria (C. rodentium), animals can rapidly mobilize their innate system (respectively through ILC2 and ILC3 activation) to increase resistance to intestinal infections.
Altogether, this study shows a functional crosstalk between the enteric nervous system and the immune system during feeding which provides an effective activation of the innate immunity to fight foodborne pathogens.
The neuropeptide VIP potentiates intestinal innate type 2 and type 3 immunity in response to feeding, Mucosal Immunology, May 2, 2022