Identification of atherosclerosis-associated conformational heat shock protein 60 epitopes by phage display and structural alignment

• Published in: Atherosclerosis 2007-09, Vol.194 (1), p.79-87
• Main Authors: Perschinka, Hannes, Wellenzohn, Bernd, Parson, Walther, van der Zee, Ruurd, Willeit, Johann, Kiechl, Stefan, Wick, Georg
• Format: Article
• Language: English
• Subjects: Aging; Amino Acid Sequence; Antibodies; Antigens, Bacterial - immunology; Associated diseases and complications; Atherosclerosis; Atherosclerosis (general aspects, experimental research); Atherosclerosis - epidemiology; Atherosclerosis - immunology; Autoantibodies - blood; Autoantibodies - immunology; Autoantigens - chemistry; Autoantigens - immunology; Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; Cardiovascular; Cardiovascular system; Chaperonin 60 - chemistry; Chaperonin 60 - immunology; Cross Reactions; Diabetes. Impaired glucose tolerance; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Epitopes - chemistry; Epitopes - immunology; Heat shock protein 60; Humans; Investigative techniques, diagnostic techniques (general aspects); Medical sciences; Models, Molecular; Molecular modelling; Mycobacterium - immunology; Peptide Library; Phage display; Protein Structure, Quaternary; Protein Structure, Tertiary; Risk Factors; Structural alignment; Ultrasonic investigative techniques
• ISSN: 0021-9150; 1879-1484
• DOI: 10.1016/j.atherosclerosis.2006.09.028

Abstract Autoimmune reactions to HSP60 are believed to play a key role during development of early atherosclerosis. Due to the high degree of phylogenetic conservation between microbial and human HSP60, bacterial infections might be responsible for inducing cross-reactivity to self HSP60, which is expressed on the surface of arterial endothelial cells stressed by classical atherosclerosis risk factors. Conformational epitopes recognized by polyclonal anti-mycobacterial HSP60 antibodies from subjects with atherosclerosis were identified using a phage displayed random library of cyclic constrained 7mer peptides. After five rounds of selection, DNA sequencing of strongly binding clones revealed that one peptide motif (CIGSPSTNC) was present in 64% of all clones, and a second motif (CSFHYQNRC) in 14%. Using a newly developed method for structural alignment of small constrained peptides onto a protein surface, we located the motif present in 14% of all clones on the surface of mycobacterial HSP60. The motif present in 64% of all clones was found on the surface of mycobacterial HSP60 as well as in the homologous region of human HSP60, which makes this epitope a promising candidate for further investigations on cross-reactive epitopes involved in early atherogenesis.