Strain matters in mouse models of peanut-allergic anaphylaxis: Systemic IgE-dependent and Ara h 2-dominant sensitization in C3H mice.

Background: Peanut allergy accounts for the majority of food-induced hypersensitivity reactions and can lead to lethal anaphylaxis. Animal models can provide an insight into the immune mechanisms responsible for sensitization and allergic anaphylaxis. However, different mouse strains and sensitization protocols can influence the successful development of a peanut allergic mouse model.

Objective: We aimed at developing a systemic anaphylaxis model of peanut allergy that resembles human anaphylaxis. We compared the immunological and clinical responses in genetically different mouse strains.

Methods: Female BALB/c, C57BL/6, and C3H mice were intraperitoneally sensitized and later challenged with peanut proteins. Allergen-specific serology was done by ELISA, and anaphylaxis was evaluated by monitoring changes in body temperature upon systemic challenge.

Results: Sensitization to peanut was successful in C3H mice and triggered production of allergen-specific antibodies, cytokines and anaphylaxis. Allergic reactions were characterized by the release of allergic mediators and by changes in leukocyte populations in blood and in the peritoneal cavity. Among the identified major peanut allergens, Ara h 2 showed the strongest anaphylactic potential. Much lower or no trigger of peanut-specific antibodies was observed in BALB/c and C57BL/6 mice, which experienced no hypersensitivity reactions.

Conclusions: Mouse strain matters for testing of peanut protein allergens. We identified C3H mice as a suitable strain for the development of a mouse model of peanut-allergic anaphylaxis. Pre-clinical, humoural and cellular responses resembled the responses observed in human patients. The described model can be useful for further studies on peanut allergy and for the development of new therapeutic strategies.