Mechanisms underlying the localisation of mast cells in tissues.

Mast cells are tissue-resident cells best known for their role in allergy and host defence against helminth parasites. They are involved in responses against other pathogenic infections, wound healing and inflammatory disease. Committed mast cell progenitors are released from the bone marrow into the circulation, from where they are recruited into tissues to complete their maturation under the control of locally produced cytokines and growth factors. Directed migration occurs at distinct stages of the mast cell life-cycle and is associated with successive up- and downregulation of cell surface adhesion molecules and chemoattractant receptors as the cells mature. This article discusses some of the recent advances in our understanding of the mechanisms underlying mast cell recruitment.