Aim: To compare the immunological and clinical changes induced by allergen-specific immunotherapy (AIT) using different adjuvants.
Materials & methods: Olea europaea pollen-sensitized mice were treated with olea plus aluminum hydroxide, calcium phosphate, monophosphoryl lipid A (MPL) or immunostimulatory sequences (ISS).
Results: Aluminum hydroxide seems to drive initially to a Th2-type response. Bacteria-derived adjuvants (MPL and ISS) skew the immune response toward Th1 and Treg pathways. Specific-IgE production was lower after AIT with MPL and ISS. Moreover, IgG2a production significantly increased in ISS-treated mice. Bacteria-derived adjuvants also improved the Th1 cytokine response due to IFN-γ higher secretion. In addition, they improved bronchial hyper-reactivity and lung inflammation.
Conclusion: Bacteria-derived adjuvants may enhance the efficacy of AIT.
Keywords: adjuvants; allergen-specific immunotherapy; allergic asthma; aluminum hydroxide; calcium phosphate; immunostimulatory sequences; monophosphoryl lipid A; murine model.