Involvement of the peripheral sensory structures of the autonomic nervous system in the mechanisms of neuroimmune interactions

This review presents results from studies seeking evidence of the involvement of sensory structures in mediating signal interactions between the immune and nervous systems in the gastrointestinal tract. The data reported here provide evidence that the terminals of small intestine afferent fibers modulate the body’s reactions to administration of antigenic structures. The question of the involvement of intrinsic enteric neurons in these processes has received insufficient study. The data presented here provide evidence that enteric neurons express the innate immunity TLR4 receptor and the nociceptive vanilloid TRPV1 receptor. Analysis of the distribution of nerve cells in intramural ganglia showed that vanilloid receptors are expressed by neurons located mainly within muscle sheaths, while TLR4-immunoreactive neurons are mostly present in the submucosal plexus. Coexpression of both receptors at the level of single enteric neurons has been demonstrated. Published results indicate that innate immunity and nociceptive receptors may interact during bacterial invasion or inflammation. Thus, intrinsic enteric neurons in the intestine, like extrinsic sensory neurons, are involved in neuroimmune interactions. © 2016 Springer Science+Business Media New York.