Degranulation of basophilic leukemia cells on branched-chain peptide array with an OVA–DNP double epitope

• Published in: Biochemical engineering journal 2014-06, Vol.87, p.8-14
• Main Authors: Sugiura, Hisayuki, Okazaki, Noriyasu, Sugiura, Toshimi, Honda, Hiroyuki, Okochi, Mina
• Format: Article
• Language: English
• Subjects: Allergy; Biological and medical sciences; Biotechnology; Degranulation; Fundamental and applied biological sciences. Psychology; Heterovalent epitopes; IgE antibody; Peptide array
• ISSN: 1369-703X; 1873-295X
• DOI: 10.1016/j.bej.2014.03.008

•The degranulation assay system using a spot-synthesized peptide array was developed.•Using lysine side chains, the double epitope branched-chain peptide was synthesized.•This model incorporates epitope heterogeneity and induced degranulation on array. Simple method for identification of heterovalent allergen epitopes was constructed to reflect the allergic reaction initiated by the cross-linking of the IgE receptors. The peptide array-based degranulation assay that enables interaction between solid support-bound peptide pairs and IgE sensitized basophilic leukemia cells was developed. Using lysine side chains, a chicken egg white ovalbumin (OVA) epitope and a dinitrophenol (DNP) modified amino acid was synthesized in the branched-chain peptide array. The basophilic leukemia cells sensitized with anti-OVA IgE and anti-DNP IgE induced degranulation directly on the branched-chain peptide array. The OVA–DNP double peptide disk caused the release of 37.5% of β-hexosaminidase whereas the DNP-only peptide disk caused the release by 20.9%. These results show that the double epitope branched-chain peptide array can induce degranulation, and would represent a suitable model for screening the heterovalent epitope pairs of allergens.