475 The Candidate Peptides in IgE for Allergy Vaccine Design

BACKGROUND: The World Allergy Organization in 2011 estimated that 30 to 40% of the world population is now affected by one or more allergic conditions. Since the IgE plays a central role in the expansion and regulation of allergic response that seems the IgE elimination is the best approach in the control of asthma and allergic diseases. Now, an anti-IgE antibody as a drug (Xolair) is available and efficient but is expensive with short half-life. As good and more efficient substitution IgE peptide-based vaccines has been proposed. METHODS: In this study, we analyzed all potential antigenic peptides on the constant region of the Ig epsilon chain (Fcε). For determination of B cell immunodominant epitope, we used the antibody epitope prediction tools. In continuing candidate peptides were done BlastP to avoid nonspecific antibody reactions with other human proteins in the NCBI database. And then, to preparation of vaccines, peptides were synthesized and conjugated by Tetanus toxoid (TT). To immunogenicity analysis of vaccines, the rats are being immunized with vaccines or TT as control. RESULTS: By Kolaskar and Tongaonkar antigenicity algorithms 20 peptides with putative epitopes were selected. Homologous sequences and also previous studies peptides were excluded, 13 peptides remained that used for vaccine preparation. The produced vaccines are being analyzed for their effect on induction of anti-IgE antibody production. Peptides based on antibody production or not, were divided in 2 groups. CONCLUSIONS: Active immunization by IgE peptide based vaccines can be triggering production antibodies against self-IgE that are effective in preventing and control of IgE levels as an important factor in asthma and allergic diseases.