title: Peptide mimotopes of malondialdehyde epitopes for clinical applications in cardiovascular disease.
abstract: Autoantibodies specific for malondialdehyde-modified LDL (MDA-LDL) represent potential biomarkers to predict cardiovascular risk. However, MDA-LDL is a high variability antigen with limited reproducibility. To identify peptide mimotopes of MDA-LDL, phage display libraries were screened with the MDA-LDL-specific IgM monoclonal Ab LRO4, and the specificity and antigenic properties of MDA mimotopes were assessed in vitro and in vivo. We identified one 12-mer linear (P1) and one 7-mer cyclic (P2) peptide carrying a consensus sequence, which bound specifically to murine and human anti-MDA monoclonal Abs. Furthermore, MDA mimotopes were found to mimic MDA epitopes on the surface of apoptotic cells. Immunization of mice with P2 resulted in the induction of MDA-LDL-specific Abs, which strongly immunostained human atherosclerotic lesions. We detected IgG and IgM autoAbs to both MDA mimotopes in sera of healthy subjects and patients with myocardial infarction and stable angina pectoris undergoing percutaneous coronary intervention, and the titers of autoAbs correlated significantly with respective Ab titers against MDA-LDL. In conclusion, we identified specific peptides that are immunological mimotopes of MDA. These mimotopes can serve as standardized and reproducible antigens that will be useful for diagnostic and therapeutic applications in cardiovascular disease.
authors.affiliation: Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: Shahzada
authors.initials: S
authors.lastname: Amir
authors.forename: Karsten
authors.initials: K
authors.lastname: Hartvigsen
authors.forename: Ayelet
authors.initials: A
authors.lastname: Gonen
authors.forename: Gregor
authors.initials: G
authors.lastname: Leibundgut
authors.forename: Xuchu
authors.initials: X
authors.lastname: Que
authors.forename: Erika
authors.initials: E
authors.lastname: Jensen-Jarolim
authors.forename: Oswald
authors.initials: O
authors.lastname: Wagner
authors.forename: Sotirios
authors.initials: S
authors.lastname: Tsimikas
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Witztum
authors.forename: Christoph J
authors.initials: CJ
authors.lastname: Binder
mesh_terms: D000818:Animals; D001323:Autoantibodies / Q000276:immunology; D002318:Cardiovascular Diseases / Q000276:immunology* / Q000473:pathology; D000939:Epitopes / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D008077:Lipoproteins, LDL / Q000276:immunology; D008315:Malondialdehyde / Q000031:analogs & derivatives / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D010455:Peptides / Q000276:immunology*; D011973:Receptors, LDL / Q000172:deficiency / Q000276:immunology
chemical_list: D001323:Autoantibodies; D000939:Epitopes; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D008077:Lipoproteins, LDL; D010455:Peptides; D011973:Receptors, LDL; C569869:malondialdehyde-low density lipoprotein, human; D008315:Malondialdehyde