The IgE-Reactive Autoantigen Hom s 2 Induces Damage of Respiratory Epithelial Cells and Keratinocytes via Induction of IFN-[gamma]

• Published in: Journal of investigative dermatology Vol. 128; no. 6; p. 1451
• Main Authors: Mittermann, Irene, Reininger, Renate, Zimmermann, Maya, Gangl, Katharina, Reisinger, Jürgen, Aichberger, Karl J, Greisenegger, Elli K, Niederberger, Verena, Seipelt, Joachim, Bohle, Barbara, Kopp, Tamara, Akdis, Cezmi A, Spitzauer, Susanne, Valent, Peter, Valenta, Rudolf
• Format: Journal Article
• Language: English
• Published: London Elsevier Limited 01.06.2008
• ISSN: 0022-202X; 1523-1747
• DOI: 10.1038/sj.jid.5701195

Hom s 2, the alpha-chain of the nascent polypeptide-associated complex, is an intracellular autoantigen that has been identified with IgE autoantibodies from atopic dermatitis patients. We investigated the humoral and cellular immune response to purified recombinant Hom s 2 (rHom s 2). rHom s 2 exhibited IgE reactivity comparable to exogenous allergens, but did not induce relevant basophil cell degranulation. The latter may be attributed to the fact that patients recognized single epitopes on Hom s 2 as revealed by IgE epitope mapping with rHom s 2 fragments. In contrast to exogenous allergens, rHom s 2 had the intrinsic ability to induce the release of IFN-gamma in cultured peripheral blood mononuclear cells from atopic as well as non-atopic individuals. IFN-gamma-containing culture supernatants from Hom s 2-stimulated peripheral blood mononuclear cells caused disintegration of respiratory epithelial cell layers and apoptosis of skin keratinocytes, which could be inhibited with a neutralizing anti-IFN-gamma antibody. Our data demonstrate that the Hom s 2 autoantigen can cause IFN-gamma-mediated cell damage.