A Biotinylated Heptapeptide Containing a D-Amino Acid Suppresses Both IgE-Dependent and -Independent Allergic Edema in Mice.

We previously found that, among three biotinylated heptapeptides (Peptide 1, Peptide 2, and Peptide 3) derived from the amino acid sequence of Asp-hemolysin, a protein toxin produced by Aspergillus fumigatus, Peptide 2, which contains a d-amino acid, exhibits potent anti-allergic activity in vitro and in vivo. In this study, we evaluated the effects of Peptide 2 on immunoglobulin E (IgE)-dependent allergic edema induced by ovalbumin (OVA) in OVA-specific IgE transgenic mice, IgE-independent allergic edema induced by compound 48/80 (C48/80), and nonallergic inflammatory edema induced by histamine, serotonin, bradykinin, zymosan A, and λ-carrageenan. Peptide 2 significantly suppressed both OVA-IgE- and C48/80-induced paw edema, indicating inhibitory effects on both IgE-dependent and -independent allergic responses. Peptide 2 also dose-dependently inhibited histamine-induced edema but did not affect serotonin-, bradykinin-, zymosan A-, or λ-carrageenan-induced edema. These findings indicate that Peptide 2 modulates IgE-dependent and -independent allergic responses involving mast cell activation and histamine-related pathways and may be a candidate for the development of selective anti-allergic agents.