Identification of atherosclerosis-associated conformational heat shock protein 60 epitopes by phage display and structural alignment.
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.
Perschinka
Hannes
H
Division of Experimental Pathophysiology and Immunology, Biocenter, Innsbruck Medical University, Fritz-Pregl-Str. 3/IV, 6020 Innsbruck, Austria.
Wellenzohn
Bernd
B
Parson
Walther
W
van der Zee
Ruurd
R
Willeit
Johann
J
Kiechl
Stefan
S
Wick
Georg
G
D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000276:immunology; D050197:Atherosclerosis / Q000453:epidemiology / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood / Q000276:immunology; D001324:Autoantigens / Q000737:chemistry / Q000276:immunology; D018834:Chaperonin 60 / Q000737:chemistry* / Q000276:immunology*; D003429:Cross Reactions; D000939:Epitopes / Q000737:chemistry* / Q000276:immunology*; D006801:Humans; D008958:Models, Molecular; D009161:Mycobacterium / Q000276:immunology; D019151:Peptide Library; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D012307:Risk Factors
D000942:Antigens, Bacterial; D001323:Autoantibodies; D001324:Autoantigens; D018834:Chaperonin 60; D000939:Epitopes; D019151:Peptide Library