CpG Immunotherapy in Chenopodium album sensitized mice: The comparison of IFN-gamma, IL-10 and IgE responses in intranasal and subcutaneous administrations

BACKGROUND Mucosal-based immunotherapy has been already used as an alternative form of allergen delivery. In asthma, the poor success rate of immune modulation could be a consequence of inadequate immune modulation in the airways. Previously, we have found that subcutaneous (S.C) co-administration of a homemade allergenic extract from Chenopodium album (Ch.a) pollen and Guanine-Cytosine containing deoxynucleotides (CpG-ODNs) is effective to prevent the inflammatory responses in mouse. In this study we used CpG/Ch.a for immunotherapy of Ch.a-induced asthma and compared the intranasal (I.N) and S.C routes of administration concerning IFN-gamma, IL-10 and total IgE responses. METHODS Ch.a sensitized mice were treated intranasaly or subcutaneously using CpG and Ch.a. extract. IFN-gamma, IL-10 and total IgE were measured in supernatant culture of splenocytes and bronchoalveolor lavage (BAL) fluids by ELISA. Student's t test was used in the analysis of the results obtained from the test and control mice. RESULTS We found that I.N administration of CpG/Ch.a in sensitized mice significantly increased the production of systemic and mucosal IFN-gamma and IL-10 compared to phosphate buffered saline (PBS), Ch.a alone and control ODNs treated sensitized mice (P </= 0.001). On the other hand, S.C. route induced the systemic and mucosal IFN-gamma in the lower levels than in I.N one, and failed to increase systemic IL-10 induction (P = 0.06). Total serum IgE in CpG/Ch.a treated mice in both routes showed significant decreases compared to three control groups (P </= 0.01). The amounts of IgE in BAL fluids were not measurable in all groups. CONCLUSION According to the results of this experiment we concluded that immunotherapy via the I.N co-administration of CpG/Ch.a in comparison with S.C route is more effective to stimulate the mucosal and regulatory responses in Ch.a induced asthma.