Control of lymph node activity by direct local innervation

The nervous system detects environmental and internal stimuli and relays this in-formation to immune cells via neurotransmitters and neuropeptides. This is es-sential to respond appropriately to immunogenic threats and to support system homeostasis. Lymph nodes (LNs) act as sentinels where adaptive immune re-sponses are generated. They are richly innervated by peripheral sympathetic and sensory nerves, which are responsible for the local secretion of neurotrans-mitters by sympathetic fibers, such as norepinephrine, and neuropeptides by sensory fibers, including calcitonin gene-related peptide (CGRP) and substance P. Additionally, time-of-day-dependent oscillations in nerve activity are associ-ated with differential immune responses, suggesting a potential role for neuroimmune interactions in coordinating immunity in a circadian fashion. Here, we discuss how LN activity is controlled by local innervation.

Automated summary

The nervous system communicates with immune cells through neurotransmitters and neuropeptides to respond to immune threats and maintain system homeostasis. Lymph nodes, as the sites of adaptive immune responses, are extensively innervated by peripheral nerves that secrete neurotransmitters and neuropeptides. Time-dependent fluctuations in nerve activity may play a role in coordinating immunity in a circadian fashion.