Mast cell allergic sensitization

Mast Cells and Mast Cell-Derived Factors in the Regulation of Allergic Sensitization... 

Skin Models Implicate a Role for Mast Cells in Priming of Adaptive Immune Responses and Allergic Sensitization... 

Mast cells influence the long-term consequences and the resolution of CHS beginning 3 days after challenge of sensitized animals with DNFB or urushiol. Production of the immunosuppressive cytokine lL-10 by mast cells strongly contributed to these late anti-inflammatory effects of mast cells. Thus, this example demonstrates for the first time that mast cells are able to truly modulate - and not only to promote - allergic responses. 

Machado DC, Horton D, Harrop R, Peachell PT, Helm BA Potential allergens stimulate the release of mediators of the allergic response from cells of mast cell lineage in the absence of sensitization with antigen-specific IgE. 

Despite the fact that a definite decrease in IgE antibody levels and IgE-mediated skin sensitivity normally requires several years of SIT, most patients are protected against bee stings already at an early stage of bee venom-SIT. The reason for this is that effector cells of allergic inflammation, such as mast cells, basophils and eosinophils. 

By a negative feedback control mechanism mediated by H2 receptors, histamine appears to modulate its own release and that of other mediators from sensitized mast cells in some tissues. In humans, mast cells in skin and basophils show this negative feedback mechanism lung mast cells do not. Thus, histamine may act to limit the intensity of the allergic reaction in the skin and blood. 

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