The Expression and Function of CD300 Molecules in the Main Players of Allergic Responses: Mast Cells, Basophils and Eosinophils

Abstract

Allergy is the host immune response against non-infectious substances called allergens. The prevalence of allergic diseases is increasing worldwide. However, while some drugs counteract the symptomatology caused by allergic reactions, no completely effective treatments for allergic diseases have been developed yet. In this sense, the ability of surface activating and inhibitory receptors to modulate the function of the main effector cells of allergic responses makes these molecules potential pharmacological targets. The CD300 receptor family consists of members with activating and inhibitory capabilities mainly expressed on the surface of immune cells. Multiple studies in the last few years have highlighted the importance of CD300 molecules in several pathological conditions. This review summarizes the literature on CD300 receptor expression, regulation and function in mast cells, basophils and eosinophils, the main players of allergic responses. Moreover, we review the involvement of CD300 receptors in the pathogenesis of certain allergic diseases, as well as their prospective use as therapeutic targets for the treatment of IgE-dependent allergic responses.

Dexamethasone and CD300a activation display additive inhibitory effect on human and murine mast cell functions

“…4 CD300a, expressed on immune cells including MCs, eosinophils, and basophils, 5 is a cell surface inhibitory receptor whose defined ligands are phosphatidyl-serine and phosphatidyl-ethanolamine. 5 CD300a in humans is characterized by a single extracellular V-type Ig-like domain and an intra-cellular domain with three classical ITIM motifs. 5 Upon phosphorylation, CD300a ITIMs recruit and activate intra-cellular phosphatases (such as SHP-1 and SHIP-1) which dephosphorylate key activating signal transduction molecules and thereby lead to inhibition of cell activation.…”

“…5 CD300a in humans is characterized by a single extracellular V-type Ig-like domain and an intra-cellular domain with three classical ITIM motifs. 5 Upon phosphorylation, CD300a ITIMs recruit and activate intra-cellular phosphatases (such as SHP-1 and SHIP-1) which dephosphorylate key activating signal transduction molecules and thereby lead to inhibition of cell activation. 5 The mouse homologue of CD300a-LMIR-1 shares 80% homology and has a similar inhibitory function on MCs 5 therefore we used the 'CD300a' terminology also for the murine receptor.…”

“…5 Upon phosphorylation, CD300a ITIMs recruit and activate intra-cellular phosphatases (such as SHP-1 and SHIP-1) which dephosphorylate key activating signal transduction molecules and thereby lead to inhibition of cell activation. 5 The mouse homologue of CD300a-LMIR-1 shares 80% homology and has a similar inhibitory function on MCs 5 therefore we used the 'CD300a' terminology also for the murine receptor. We have previously shown that CD300a is expressed and functional in both human and murine MCs.…”

Increased Frequency of CTLA-4 and PD-1 Expressing Regulatory T Cells and Basophils With an Activating Profile in Infants With Moderate-to-Severe Atopic Dermatitis Hypersensitized to Food Allergens

“…The immune response is also regulated, among others, by activating and inhibitory receptors expressed on the surface of immune cells. In this sense, the involvement of CD300 surface receptors in the regulation of allergic responses has been demonstrated (34)(35)(36)(37)(38)(39). It is known that CD300a expressed on basophils suppresses the basophil anaphylactic degranulation by its interaction with phosphatidylserine and phosphatidylethanolamine exposed on apoptotic cells (34,35), whereas CD300c works as a costimulatory molecule during immunoglobulin E (IgE)-mediated basophils activation (37).…”

Human primitive mesenchymal stem cell-derived retinal progenitor cells promoted neuroprotection and neurogenesis in rd12 mice

“…Since qRT-PCR is a highly sensitive technique, the differences in DEG expression were many log fold higher. Some highly expressed genes in RPC transplanted animals were also associated with anti-inflammatory response [58] . While the other highly expressed genes are known to play a role in neuronal and retinal development.…”