Molecular mimicry of the unidentified antigen of myeloma antibody IgE‐ND

• Published in: European journal of immunology 1999-09, Vol.29 (9), p.2676-2683
• Main Authors: Thurnheer, M. Christine, Zuercher, Adrian W., Miescher, Sylvia M., Rudolf, Michael P., Vogel, Monique, Stadler, Beda M.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Antibodies, Neoplasm - chemistry; Antibody Specificity; Antigens, Neoplasm - immunology; Bacteriophages - immunology; Binding, Competitive; Cells, Cultured; CHO Cells; Cricetinae; Epitopes - isolation & purification; Human IgE; Humans; Immunoglobulin E - chemistry; Immunoglobulin E - metabolism; Mimotope; Molecular Mimicry - immunology; Molecular Sequence Data; Multiple Myeloma - immunology; Peptide Library; Phage display; Random peptide; Receptors, IgE - metabolism
• ISSN: 0014-2980; 1521-4141
• DOI: 10.1002/(SICI)1521-4141(199909)29:09<2676::AID-IMMU2676>3.0.CO;2-O

Antigen‐specific human IgE is in short supply. Thus, we sought to determine the yet unknown specificity of a widely available human IgE, namely the myeloma cell line U266‐derived IgE‐ND. For this purpose highly specific peptides able to mimic the putative antigen recognized by IgE‐ND were isolated from phage‐display random peptide libraries. Interestingly, we found linear sequence homologies of the IgE‐ND‐binding peptides with self antigens and a xenoantigen from Thiobacillus ferrooxidans. However, none of these antigens was recognized by IgE‐ND. Nevertheless, our approach may be applied to identify antigen specificities of myeloma antibodies. Importantly, the mimotopes were anaphylactogenic in a histamine release assay using human basophils sensitized with IgE‐ND. Thus, our mimotopes represent functional albeit synthetic antigens and may be used to study human antigen‐specific IgE responses.