469:
Intragastric sensitization to peanut in the absence of a Th2-skewing adjuvant in mice genetically predisposed to food allergy
Sunday, March 4, 2018
South Hall A2 (Convention Center)
Johanna Smeekens, PhD, Kelly Orgel, BS, Martin T. Ferris, PhD, Darla Miller, A. Wesley Burks, MD FAAAAI, Fernando Pardo-Manuel de Villena, Mike D. Kulis, PhD
RATIONALE:

Recently, we identified a Collaborative Cross mouse strain (CC027) that is orally reactive to peanut following sensitization with peanut plus cholera toxin. Interestingly, these mice were found to produce detectable levels of peanut-specific IgE before sensitization with peanut and cholera toxin. Accordingly, we aimed to determine whether CC027 mice could be sensitized to peanut without the use of any adjuvant.

METHODS:

CC027 female mice aged 4-6 weeks were sensitized intragastrically with peanut extract once per week or three times per week for four weeks. Mice were bled for IgE measurements and orally challenged with peanut.

RESULTS:

Body temperature decreases during the peanut challenge demonstrated that mice sensitized without an adjuvant reacted to peanut, and the frequency per week determined reaction severity. Mice sensitized with peanut three times per week had significantly larger decreases in temperature (mean -4.5 °C) compared to mice sensitized only once per week (mean -1.6 °C) (p=0.0065). Peanut-specific IgE levels increased in mice treated three times per week compared to naïve mice (p=0.0095).

CONCLUSIONS:

CC027 mice can be sensitized through the gastrointestinal tract with peanut in the absence of strong mucosal adjuvants. Mice given peanut three times per week were more allergic than mice sensitized only once per week indicating that frequency of antigen administration may drive severity of allergy. Previous reports have demonstrated that mice can be sensitized to peanut epicutaneously, whereas this model is the first to show that mice can be sensitized intragastrically to peanut without an adjuvant, which may mimic peanut sensitization in humans.