Mast Cells in Neuroimmune Interactions

Mast cells, while best known for their role in allergic inflammation, have diverse physiologic roles including innate defense against infection, modulation of adaptive immunity, angiogenesis, and tissue homeostasis. Mast cells and neurons are closely aligned, anatomically and functionally, throughout the body. Mast cell activity is modulated by neurotransmitters, allowing them to act as conduits for peripheral and central nervous system control of inflammation, immunity, hemodynamics, and tissue remodeling. Mast cells act as components of the somatosensory system, responding to environmental cues and relaying signals to the nervous system resulting in changes in neural activity, sensitivity, and phenotype. Mast cells localize to a specific brain region and play a role in normative behavior. There is also growing evidence that aberrant brain mast cell function may contribute to neurodegenerative, neurodevelopmental, and mood disorders. A major aspect of the regulatory function of mast cells appears to be their role as intermediaries between the nervous and immune systems. Mast cells are activated by neurotransmitters allowing neural control of innate and adaptive immunity. Conversely, mast cells secrete mediators including neurotransmitters and neurotrophic factors that directly influence nerves, causing acute activation and/or long-lasting changes in excitability and phenotype. While some basic mechanisms underlying mast cell–nerve communication are well-established, the full extent to which this relationship influences health and disease is unclear. Future studies of mast cell–nerve interactions may provide greater understanding of how immune and nervous systems coordinate multiple aspects of homeostatic control, and will potentially offer therapeutic targets in both immune and neurological disorders. A major aspect of the regulatory function of mast cells appears to be their role as intermediaries between the nervous and immune systems. Mast cells are activated by neurotransmitters allowing neural control of innate and adaptive immunity. Conversely, mast cells secrete mediators including neurotransmitters and neurotrophic factors that directly influence nerves, causing acute activation and/or long-lasting changes in excitability and phenotype. While some basic mechanisms underlying mast cell–nerve communication are well-established, the full extent to which this relationship influences health and disease is unclear. Future studies of mast cell–nerve interactions may provide greater understanding of how immune and nervous systems coordinate multiple aspects of homeostatic control, and will potentially offer therapeutic targets in both immune and neurological disorders.