Egg yolk augments type 2 immunity by activating innate cells

Area of Science:

• Immunology
• Gastroenterology
• Allergy Research

Background:

• Egg allergy is a common food allergy, with sensitization occurring in the gut.
• Egg yolk (EY) may influence the development of egg allergy through type 2 immune responses.

Purpose of the Study:

• To investigate the mechanism and role of egg yolk (EY) in inducing egg white (EW) allergy.
• To understand how EY affects intestinal immune responses during allergy sensitization.

Main Methods:

• BALB/c mice were intragastrically administered egg white (EW), egg yolk (EY), or a mixture (EW:EY).
• In vitro experiments involved intestinal epithelial cells (IECs), dendritic cells (DCs), and T cells.
• Evaluated inflammatory and type 2 immune responses, including cytokine expression and immune cell populations.

Main Results:

• EW administration upregulated duodenal factors related to barrier integrity and type 2 immunity.
• EW:EY mixture significantly increased expression of IL-25, TSLP, IL-33, and group 2 innate lymphoid cells (ILC2s) compared to EW alone.
• EW:EY enhanced specific gene and cytokine expression in Peyer's patches and mesenteric lymph nodes, promoting Th2 responses in vitro.

Conclusions:

• Co-administration of EY with EW promotes sensitization to EW.
• EY activates innate immune cells like IECs, DCs, and ILC2s, which are crucial in allergy development.
• The findings highlight EY's role in initiating and progressing food allergies.