Bi-directional neuro-immune communication regulates host defense against helminth infection
Emerging studies reveal that neuropeptides play critical role in regulating anti-helminth immune responses, hinting at the potential of intrinsic enteric neurons (iENs) in orchestrating intestinal immunity. However, whether and how the iENs get activated during infection, and whether they engage in a bi-directional communication with the immune cells, remain poorly defined. Here we show that iENs became activated in response to helminth infection. Single-nucleus RNA sequencing of the iENs revealed significant alterations in gene expression in IL-13R+ intrinsic primary afferent neurons (IPANs), including the upregulation of the neuropeptide ?-CGRP. Using genetic mouse models, we demonstrated that both group 2 innate lymphoid cells (ILC2s) and neuronal IL-13R signaling are indispensable for optimal iEN activation, which subsequently inhibit ILC2 responses and anti-helminth immunity. Together, these results reveal a previously unrecognized bi-directional neuro-immune crosstalk in the intestine. Overall design: Baf53-cre Sun1-GFP (CTL) mice or Baf53-cre Il13ra1 flox Sun1-GFP (CKO) mice were injected subcutaneously with 500 third-stage larvae (L3) Nippostrongylus brasiliensis (N. brasiliensis)  in 250 µl PBS. Muscularis externa were harvested on day 5 after the infection for nucleus isolation and fluorescence-activated cell sorting (FACS). Then the flow-sorted GFP+ nuclei were pooled for gene expression library and Feature Barcode library construction via using Chromium Next GEM Single Cell 3' Reagent Kits v3.1 (10×Genomics).