A transcriptional toolbox for exploring peripheral neuro-immune interactions.

Correct communication between immune cells and peripheral neurons is crucial for the protection of our bodies. Its breakdown is observed in many common, often painful conditions, including arthritis, neuropathies and inflammatory bowel or bladder disease. Here, we have characterised the immune response in a mouse model of neuropathic pain using flow cytometry and cell-type specific RNA sequencing (RNA-seq). We found few striking sex differences, but a very persistent inflammatory response, with increased numbers of monocytes and macrophages up to 3½ months after the initial injury. This raises the question of whether the commonly used categorisation of pain into "inflammatory" and "neuropathic" is one that is mechanistically appropriate. Finally, we collated our data with other published RNA-seq datasets on neurons, macrophages and Schwann cells in naïve and nerve injury states. The result is a practical web-based tool for the transcriptional data-mining of peripheral neuroimmune interactions.