Neurotransmitter and neuropeptide regulation of gut immunity

It is increasingly clear that the nervous system and immune system share a common molecular dialogue for intersystem communication. One of the key mechanisms of this communication is via neurotransmitters and neuropeptides. Diverse neuronal subtypes interact with various immune cell populations via the release of a wide variety of these neuromodulators that bind to receptors on immune cells. In the gut, this communication occurs via gut-intrinsic enteric neurons, extrinsic sensory and autonomic neurons. Here, we highlight a few key neurotransmitters and neuropeptides that have been shown to play a role in gut inflammation and host defense by acting on immune cells. Aberrations in this communication can lead to disorders including autoimmunity and tissue inflammation. We also discuss the need to better understand the molecular code of neuroimmune communication, which could lead to approaches to improve gut function and health.