Mucosal Mast Cells as Key Effector Cells in Food Allergies

Abstract

Mucosal mast cells (MMCs) localized in the intestinal mucosa play a key role in the development of IgE-mediated food allergies. Recent advances have revealed that MMCs are a distinctly different population from connective tissue mast cells localized in skin and other connective tissues. MMCs are inducible and transient cells that arise from bone marrow-derived mast cell progenitors, and their numbers increase rapidly during mucosal allergic inflammation. However, the mechanism of the dramatic expansion of MMCs and their cell functions are not well understood. Here, we review recent findings on the mechanisms of MMC differentiation and expansion, and we discuss the potential for the inducers of differentiation and expansion to serve as targets for food allergy therapy. In addition, we also discuss the mechanism by which oral immunotherapy, a promising treatment for food allergy patients, induces unresponsiveness to food allergens and the roles of MMCs in this process. Research focusing on MMCs should provide useful information for understanding the underlying mechanisms of food allergies in order to further advance the treatment of food allergies.

Development of mouse model for oral allergy syndrome to identify IgE cross-reactive pollen and food allergens: ragweed pollen cross-reacts with fennel and black pepper

“…We focused on lip angioedema, one of the most common symptoms of OAS, in the development of murine models of OAS. Histological analysis showed that chloroacetate esterase-stained mast cells were distributed in tissues from inside the lower lip of Balb/c mice ( Figure 1A ) and approximately 70% of the total mast cells were both toluidine blue- and chloroacetate esterase-stained mast cells, corresponding to connective tissue mast cells ( Figures 1A , B ) ( 5 , 18 , 35 , 36 , 45 ). Flow cytometric analysis showed that FcεRI + c-Kit + mast cells resided in the tissues of the lower lip ( Figure 1C ).…”

“…Food allergy is defined as a phenomenon in which adverse reactions are caused by allergen-specific immunological mechanisms following exposure to a given food ( 1 – 5 ). Oral allergy syndrome (OAS) involves the rapid onset of symptoms induced by food allergens in the oral and pharyngeal mucosa, including itching and/or angioedema of the lip, tongue, palate, and throat.…”

Oleuropein Prevents OVA‐Induced Food Allergy in Mice by Enhancing the Intestinal Epithelial Barrier and Remodeling the Intestinal Flora

“…These mediators reduce the epithelial barrier function, enhancing the contact between immune cells and antigens, further promoting FA development. [ 34 ] This study suggests a considerable growth in the release of inflammatory mediators from MMCs in allergic mice. Oleuropein remarkably reduced the expression levels of all these substances and has been shown to have a therapeutic or preventive effect in many inflammatory diseases by inhibiting the expression of the relevant inflammatory factors.…”

“…Mucosal mast cell (MMC) activation plays an important role in the onset of allergic symptoms. [ 34 ] As a distinguishing factor of MMCs, the expression of mast cell protease‐1 (mMCP‐1) in the sensitized mice was significantly higher than in the normal mice ( p < 0.05). However, the mMCP‐1 level decreased dramatically after oleuropein treatment, showing a 53.91% decline in the OLH group (20.00 mg kg −1 per day) ( Figure 7 A).…”

“…The MMCs in the intestinal mucosa play a crucial role in FA development. [ 34 ] The degranulation of the MMCs mediated by IgE releases a variety of periplasmic chemicals, such as histamine and protease (such as mMCP‐1), leading to direct allergic effects. [ 49 ] In addition, MMCs also produce a variety of inflammatory cytokines (TNF‐α, IL‐1β, INF‐γ, and IL‐4).…”