Mast cells are enigmatic cells that are recognized as critical components of our immune system. They are strategically localized at the host/environment interface, display a long lifespan once situated in tissues and have the ability to produce, store and upon activation, release...

Sphingosine‑1‑phosphate (S1P) plays important roles regulating functions of diverse biological systems, including the immune system. S1P affects immune cell function mostly by acting through its receptors at the cell membrane but it can also induce S1P receptor‑independent responses in...

A calcium signal is essential for degranulation, generation of eicosanoids and optimal production of cytokines in mast cells in response to antigen and other stimulants. The signal is initiated by phospholipase C‑mediated production of inositol 1,4,5‑trisphosphate resulting in release of...

Mast cells play a major role in allergy and anaphylaxis, as well as a protective role in immunity against bacteria and venoms (innate immunity) and T‑cell activation (acquired immunity).1,2 It was long thought that two steps are essential to mast cell activation. The first step...

Mast cells (MCs) were first described by Paul Ehrlich1 in his doctoral thesis. MCs have long been implicated in the pathogenesis of allergic reactions and certain protective responses to parasites. As most tumors contain inflammatory cell infiltrates, which often include plentiful MCs, the...

Mast cells (MCs) were once considered only as effector cells in pathogenic IgE‑ and IgG‑mediated responses such as allergy. However, developments over the last 15 years have suggested that MCs have evolved in vertebrates as beneficial effector cells that are involved in the very first...

The multiple cell types that comprise the immune system provide an efficient defense system against invading pathogens and micro‑organisms. In general, immune cells are activated for disparate functions, such as proliferation, production and release of mediators and chemotaxis, as a result...

Upon activation through high affinity IgE receptors (FcεRI), mast cells (MCs) can release up to 100% of their content of preformed mediators stored in cytoplasmic secretory granules by compound exocytosis. This causes Type I immediate hypersensitivity reactions and, in the case of...

This chapter summarizes the evidence for localized signaling domains in mast cells and basophils, with a particular focus on the high affinity IgE receptor, FceRI and its crosstalk with other membrane proteins. It is noteworthy that a literature spanning 30 years established the FceRI as a...

Mast cells often represent one of the first cells of the immune system to interact with environmental antigens, invading pathogens or environmentally‑derived toxins. Mast cells also can undergo alterations in phenotype, anatomic distribution and numbers during innate or adaptive immune...

Proteases are the most abundant class of proteins produced by mast cells. Many of these are stored in membrane‑enclosed intracellular granules until liberated by degranulating stimuli, which include cross‑linking of high affinity IgE receptor FcεRI by IgE bound to multivalent allergen....

Mast cells are derived from the hematopoietic progenitors found in bone marrow and spleen. Committed mast cell progenitors are rare in bone marrow suggesting they are rapidly released into the blood where they circulate and move out into the peripheral tissues. This migration is controlled in...

Mast cells play an important role in the lung in both health and disease. Their primary role is to initiate an appropriate program of inflammation and repair in response to tissue damage initiated by a variety of diverse stimuli. They are important for host immunity against bacterial infection...

In recent years, the field of mast cell biology has expanded well beyond the boundaries of atopic disorders and anaphylaxis, on which it has been historically focused. The biochemical and signaling events responsible for the development and regulation of mast cells has been increasingly...