Group 2 innate lymphoid cells regulate nociceptive and gait functions of the peripheral nervous system.

The peripheral nervous system (PNS) is involved in nociception and gait. The contribution of PNS-resident immune cells to these functions is not fully understood. We identified group 2 innate lymphoid cells (ILC2s) as a distinct immune cell population resident in the PNS, with a unique gene profile facilitating neuron-ILC2 cross-talk. ILC2-deficient mice display PNS dysfunction (hypersensitivity and gait anomalies). These functional deficits are attributed to structural abnormalities in the sciatic nerves of ILC2-deficient mice. ILC2s communicate with dorsal root ganglion neurons via the interleukin-13 (IL-13) signaling pathway to maintain nerve structure and pain thresholds. Loss of the shared IL-4/IL-13 receptor (IL-4R/IL-13R) in neurons results in a phenotype similar to ILC2-deficient mice. Intrathecally administered IL-13 rescues hypersensitivity and gait defects in ILC2-deficient mice, which suggests that this signaling pathway may be therapeutically important. This work therefore identifies a function for ILC2s in regulating the nerve structural integrity and nociceptive functions of the PNS.