Efficacy of local nasal immunotherapy for Dp2-induced airway inflammation in mice: Using Dp2 peptide and fungal immunomodulatory peptide

Background: Local nasal immunotherapy (LNIT) is an effective immunotherapy. Peptides derived from the group 2 allergen of Dermatophagoides pteronyssinus, Dp2 28-40 and Dp2 28-40A, and fungal immunomodulatory peptide (FIP) have been shown to act as T(H)1 potential and response-inducing adjuvant. LNIT by the use of Dp2 peptides in conjunction with FIP were investigated. Objective: We sought to determine whether Dp2-induced airway inflammation in mice could be downregulated by Dp2 peptides or a mixture of Dp2 peptides with FIP. Method: Mice were sensitized with rDp2 followed by LNIT with Dp2 peptides, FIP, or FIP and a mixture of Dp2 peptides. After intratracheal challenge with rDp2, the airway inflammation and hyperresponsiveness were determined by bronchoalveolar lavage fluid (BALF) analysis and methacholine challenge. Results: Both Dp2 peptides and FIP were able to inhibit rDp2-induced airway inflammation and airway hyperresponsiveness. An increase in IFN-gamma and a decrease in IL-5 in BALF and sera were found after LNIT with Dp2 peptides, FIP, and mixtures of both. Serum levels of TGF-beta were reduced after LNIT with FIP and Dp2 28-40. Penh values were significantly decreased after methacholine challenge in both the early and late phase. Conclusions: LNIT with allergen-derived peptides and FIP can produce an anti-inflammatory effect on allergen-induced airway inflammation. LNIT with selected peptides and FIP might be a good alternative therapy for allergic airway disease.