Type B C p G oligodeoxynucleotides induce T h1 responses to peanut antigens: Modulation of sensitization and utility in a truncated immunotherapy regimen in mice

Scope Peanut allergy stems from a T h2‐biased immune response to peanut allergens leading to I g E production and allergic reactions upon ingestion. Methods and results A model of peanut allergy in C 3 H / H e J mice was used to assess whether type A , B , or C C p G oligodeoxynucleotide ( ODN ) molecules would be effective in: (i) a prophylactic approach to prevent peanut allergy when administered simultaneously with a T h2‐skewing adjuvant, and (ii) a therapeutic model to allow for shortened immunotherapy. Type B ODN s were extremely effective in inhibiting anaphylaxis in the sensitization protocol as evidenced by differences in symptom scores, body temperature, and mouse mast cell protease 1 release compared to sham treatment. In the therapeutic model, co‐administration of type B ODN plus peanut proteins was highly effective in reducing anaphylactic reactions in mice with established peanut allergy. The therapeutic effect was accompanied by an increase in IFN ‐γ and peanut‐ I g G 2a, without a significant decrease in peanut I g E or IL ‐4 responses. Conclusion C p G ODN s, especially type B , were highly effective in inducing T h1 responses in mice undergoing induction of peanut allergy, as well as in mice undergoing therapy for established peanut allergy. Interestingly, the I g E response was not significantly altered, suggesting that I g G antibodies may be enough to prevent peanut‐induced anaphylaxis.