1. Mast Cells Y Y Y Y Y Y Y Y Y Y Y Y Y
CATEGORY: CELLS
MAST CELLS
Mast Cells
Charlotte Weller, Imperial College, London, UK
Mast cells are long-lived tissue-resident cells with an important role in many inflammatory settings including host defence to parasitic infection and in allergic reactions. Mast cells are located at the boundaries between tissues and the external environment, for example, at mucosal surfaces of the gut and lungs, in the skin and around blood vessels. Mast cells are key players in the inflammatory response as they can be activated to release a wide variety of inflammatory mediators, by many different antigens including allergens, pathogens and physiological mediators.
Resting Mast Cell
Activated Mast Cell
Fcε Receptor 1
IgE antibody Y Y Y
© The copyright for this work resides with the author Y Y Y Y
Mast-cell
Mast-cell Y Y Y Y Y Y
Resting mast cell contains granules
containing histamine and other
inflammatory mediators
Multivalent antigen cross-links
bound IgE antibody, causing
release of granule contents
Figure 1. Mast-cell activation
increase vascular permeability
smooth muscle contraction
Histamine
IL-4,
IL-13
promotes Th2 differentiation
promotes IgE production
Cytokines
TNF-α
promotes tissue inflammation
Mast-cell
activation
increase vascular permeability
cause smooth muscle contraction
stimulates mucus secretion
Chemoattractants for T cells, eosinophils, mast cells & basophils
Lipid mediators:
Leukotrienes
and Prostaglandins
Figure 2. Effects of mast-cell activation
Mast cells derive from the bone marrow but unlike other white blood cells, mast cells are released into the blood as mast cell progenitors and do not fully mature until they are recruited into the tissue where they undergo their terminal differentiation. Stem cell factor (SCF) is a cytokine essential for mast cell development, proliferation and survival. Mast cells can be distinguished from other cell types in tissue sections by Toludine blue staining that stains mast cells blue.