Novel Identified Receptors on Mast Cells

Abstract

Mast cells (MC) are major participants in the allergic reaction. In addition they possess immunomodulatory roles in the innate and adaptive immune reactions. Their functions are modulated through a number of activating and inhibitory receptors expressed on their surface. This review deals with some of the most recently described receptors, their expression patterns, ligand(s), signal transduction mechanisms, possible cross-talk with other receptors and, last but not least, regulatory functions that the MC can perform based on their receptor expression in health or in disease. Where the receptor role on MC is still not clear, evidences from other hematopoietic cells expressing them is provided as a possible insight for their function on MC. Suggested strategies to modulate these receptors’ activity for the purpose of therapeutic intervention are also discussed.

Identification of histamine receptors in the canine gastrointestinal tract

“…16 Without the central role of histamine and its corresponding H2 receptor on parietal cells, gastric acid production is significantly hampered. 17 In addition to its role in gastric acid secretion, the H2 receptor also mediates vasodilation, inotropy and chronotropy, and smooth muscle relaxation in the uterus, vasculature, and airways. 4,18 Unlike the H1 receptor, which has a pro-inflammatory role, the H2 receptor has an anti-inflammatory role through the inhibition of cytokine production and chemotaxis and dampening of T cell responses.…”

“…Similarly, formalin-fixed paraffinembedded tissue sections from a high grade malignancy (Grade III) canine cutaneous mast cell tumor were used as a positive control for H1, H2, and H4 receptor identification. 17 Peripheral nervous system tissue (intestinal ganglia) obtained from the full-thickness GI biopsies served as the positive control for H3 receptor identification. 2…”

Mast cell activation: A complex interplay of positive and negative signaling pathways

“…Mast cells respond to antigenic stimulation through the cross-linking of immunoglobulin E (IgE) bound to high-affinity receptors for IgE (FcεRI) and the activation of the FcγR after IgG binding (reviewed in [1,2]). Upon activation, mast cells release either preformed, granule-stored mediators, such as histamine and proteases, or newly generated mediators, such as eicosanoids, cytokines, and chemokines [3].…”

Deciphering new molecular mechanisms of mast cell activation

“…Thus, several reviews of this ebook describe new types of stimuli for these cells involving chemokines (Halova et al, 2012), sex hormones (Zierau et al, 2012), tetraspanins (Koberle et al, 2012), TRP channels (Freichel et al, 2012), TLRs (Sandig and Bulfone-Paus, 2012). Another article provides a general description of novel identified receptors (Migalovich-Sheikhet et al, 2012) that may act also as inhibitory receptors of an inflammatory reaction. Some contributions deal with the regulation of mast cell activation involving for example cytoskeletal elements , ion channels or tetraspanins (Freichel et al, 2012;Koberle et al, 2012), or the mechanism involved in secretory granule fusion or the crosstalk between different cell surface receptors (Lorentz et al, 2012;Migalovich-Sheikhet et al, 2012).…”

“…Another article provides a general description of novel identified receptors (Migalovich-Sheikhet et al, 2012) that may act also as inhibitory receptors of an inflammatory reaction. Some contributions deal with the regulation of mast cell activation involving for example cytoskeletal elements , ion channels or tetraspanins (Freichel et al, 2012;Koberle et al, 2012), or the mechanism involved in secretory granule fusion or the crosstalk between different cell surface receptors (Lorentz et al, 2012;Migalovich-Sheikhet et al, 2012). Another point discussed is the implication of these stimuli in new types of biological responses mediated by mast cells.…”