Intestinal mast cell-derived leukotrienes mediate the anaphylactic response to ingested antigens

Area of Science:

• Immunology
• Gastroenterology
• Allergy Research

Background:

• Anaphylaxis is a severe allergic reaction to food allergens.
• Existing mouse models of anaphylaxis often use intravenous injection, not reflecting oral ingestion.
• Mucosal exposure to allergens is critical for understanding food allergies.

Purpose of the Study:

• To investigate the role of intestinal mast cells in oral anaphylaxis.
• To understand the specific mechanisms of food allergen-induced anaphylaxis via ingestion.
• To compare intestinal mast cell functions with other mast cell populations.

Main Methods:

• Investigated mast cells in the mouse intestine following oral allergen exposure.
• Analyzed immunoglobulin E-Fcε receptor 1 (IgE-FcεR1) signaling pathways.
• Compared transcriptomes and effector functions of intestinal vs. connective tissue mast cells.
• Utilized genetic deficiency and pharmacological inhibition of leukotriene synthesis (zileuton, aLOX5 antagonist).

Main Results:

• Oral anaphylaxis necessitates IgE-FcεR1 signaling in intestinal mast cells.
• Intestinal mast cells are heterogeneous, influenced by epithelial cues, and distinct from connective tissue mast cells.
• Intestinal mast cells exhibit reduced histamine but enhanced leukotriene synthesis.
• Inhibition of leukotriene synthesis protected against oral anaphylaxis but not intravenous anaphylaxis.

Conclusions:

• Intestinal mast cells play a critical role in oral anaphylaxis.
• Leukotriene synthesis by intestinal mast cells is a key mediator of food allergy reactions.
• Targeting leukotriene pathways may offer therapeutic strategies for oral food allergies.