Chemokines and mast cells

Abstract

Mast cells derive from bone marrow stem cells, are ubiquitously distributed resident tissue cells, and are particularly frequent in the lamina propria of epithelial organs, including the skin. The cells are characterized and distinguishable from other cells by their electrondense cytoplasmatic granules, their contents of mediators like histamine, heparin and tryptase, and by their surface receptors for SCF (c-kit) and IgE (the high affinity IgE receptor, FcɛRI). Basophils which belong to the granulocytic series of the bone marrow and reside primarily in peripheral blood, are often grouped with mast cells since they share many properties with these cells except for their morphology and their lack of tryptase and c-kit. Mast cells also have a number of properties in common with other tissue resident and infiltrating inflammatory cells like the receptors c-kit on melanocytes, FceRI on Langerhans cells, and C3bR, C5aR and FcγRIII on monocytes and granulocytes. Furthermore, like most inflammatory cells, they are able to produce a broad range of mediators including leukotrienes, platelet activating factor (PAF) and cytokines. While mast cells have traditionally been viewed as primary effector cells of immediate type allergic reactions, their potential role in diverse other immunological and inflammatory processes has become more and more apparent in recent years (for review, see [1]).