Catecholamines and acetylcholine are key regulators of the interaction between microbes and the immune system.

Recent studies suggest that catecholamines (CAs) and acetylcholine (ACh) play essential roles in the crosstalk between microbes and the immune system. Host cholinergic afferent fibers sense pathogen-associated molecular patterns and trigger efferent cholinergic and catecholaminergic pathways that alter immune cell proliferation, differentiation, and cytokine production. On the other hand, microbes have the ability to produce and degrade ACh and also regulate autogenous functions in response to CAs. Understanding the role played by these neurotransmitters in host-microbe interactions may provide valuable information for the development of novel therapies.