CELLS

Mast cells are immune cells of the hematopoietic lineage that originate from pluripotent progenitor cells of the bone marrow and reside in mucosal and epithelial tissues throughout the body.^1,2

Mast cells are most commonly activated through the antigen-IgE-FcεRI cross-linking which initiates the mast cell degranulation cascade, resulting in the release of inflammatory mediators stored in mast cell granules.¹ Mast cells release a wide variety of multipotent molecules including several chemokines, growth factors, histamine, heparin, chondroitin sulfate, proteases, leukotrienes, prostanoids, and diverse inflammatory and regulatory cytokines, including a wide array of interleukins.^1,2 Several of the products may have potential autocrine, paracrine, local, and systemic effects, which can diversify mast cell functions. Additionally, the proteases released from mast cells can also degrade some of the mast cell products, thereby controlling the intensity and duration of the biological effect of such factors.²

Mast cells play an important role in innate and adaptive immune responses.¹ Mast cell functions involve regulation of several cell types including but not limited to dendritic cells, macrophages, T cells, B cells, fibroblasts, eosinophils, and endothelial and epithelial cells. They also regulate a variety of physiological functions, including vasodilation, angiogenesis, wound healing, bacterial and parasite elimination, bone growth and remodeling as well as maintain bronchial, vascular, and mineral homoeostasis. Apart from their role in inflammation and infection, mast cells also play a role in autoimmune and metabolic disorders and cancer.^1,2

FcεRI: fragment crystallizable epsilon receptor for IgE; Ig: immunoglobulin.