Neuroimmune Biology of Mast Cells

Mast cells (MCs) are immune cells derived from hematopoietic progenitor cells in bone marrow, which complete their maturation within tissues. They are widely distributed throughout the body, but strategically in high amounts in skin and mucosal surfaces. MCs can store in their granules and rapidly release a wide variety of biologically active molecules and also synthesize de novo and release an additional group of inflammatory mediators and growth factors. Some of the biological functions of these MCs-mediators are related to host defense against pathogens, inflammation, tissue remodeling and homeostasis. The MCs proximity to nerve fibers in the skin and the fact that they produce and respond to several neuropeptides, suggest the existence of an intensive bidirectional crosstalk between MCs and nerve fibers that mediates many processes in health and disease. MCs-neuron interaction is involved in neurogenic inflammation, tissue remodeling, pruritus and ultraviolet radiation (UVR)-induced immunosuppression. Evidence indicates that mast cells also participate in the development and progression of skin disorders that involves hyperproliferation and inflammation, such as allergic cutaneous reactions. Therefore, it is important to know the details of this intricate interaction to understand the exact participation of MCs in physiologic and pathologic processes.