title: Immunization of Chlamydia pneumoniae (Cpn)-infected Apob(tm2Sgy)Ldlr(tm1Her)/J mice with a combined peptide of Cpn significantly reduces atherosclerotic lesion development.
abstract: OBJECTIVE
  To investigate the antigenic effect of a peptide containing two epitopes of Chlamydia pneumoniae (Cpn) on atherosclerotic lesion formation in mice infected with Cpn.
  
  
  METHODS
  Six-week-old Apob(tm2Sgy)Ldlr(tm1Her)/J mice were immunized using a repetitive immunization multiple-sites strategy with KLH-conjugated peptides derived from the major outer membrane protein and the putative outer membrane protein 5 of Cpn. Mice were fed a high-fat diet and infected with Cpn twice during the 10-week diet period. Lesions were evaluated histologically; local and systemic immune responses were analyzed by immunohistochemistry of aorta samples and cytokine measurements in plasma samples and splenocyte supernatants.
  
  
  RESULTS
  Mice immunized with the combined Cpn peptide showed a greater reduction in lesion size compared to mice immunized with either epitope alone [54.7% vs 39.8% or 41.72%] and was also associated with a significant decrease in lesion area in descending aortas compared with those in controls (88.9% for combined Cpn peptide, 81.9% for MOMP peptide and 75.7% for Omp5, respectively). This effect was associated with a shift in the cellular composition of plaques towards decreased inflammatory cell and increased regulatory T-cell content. Additionally, the effect was also connected with decreased secretion of proinflammatory cytokines and increased production of anti-inflammatory cytokines demonstrated in plasma and in supernatant on stimulated spleen cells.
  
  
  CONCLUSIONS
  Atherosclerotic lesion formation may be promoted by Cpn infection in the presence of a high-fat diet, and reduced by immunization with the combined Cpn peptide. The combined peptide has more potential than either epitope alone in reducing atherosclerotic lesion development through Treg expansion.
authors.affiliation: The Mary and Garry Weston Molecular Immunology Laboratory, Thrombosis Research Institute, London, United Kingdom.
authors.forename: Min
authors.initials: M
authors.lastname: Xia
authors.affiliation: The Mary and Garry Weston Molecular Immunology Laboratory, Thrombosis Research Institute, London, United Kingdom ; MRC Centre for Transplantation, King's College London, London, United Kingdom.
authors.forename: Daxin
authors.initials: D
authors.lastname: Chen
authors.affiliation: Department of Medical Microbiology and Immunobiology, University of Szeged, Szeged, Hungary.
authors.forename: Valeria
authors.initials: V
authors.lastname: Endresz
authors.affiliation: Department of Medical Microbiology and Immunobiology, University of Szeged, Szeged, Hungary.
authors.forename: Ildiko
authors.initials: I
authors.lastname: Faludi
authors.affiliation: Institute of Surgical Research, University of Szeged, Szeged, Hungary.
authors.forename: Andrea
authors.initials: A
authors.lastname: Szabo
authors.affiliation: Virology, National Center for Epidemiology, Budapest, Hungary.
authors.forename: Eva
authors.initials: E
authors.lastname: Gonczol
authors.affiliation: The Mary and Garry Weston Molecular Immunology Laboratory, Thrombosis Research Institute, London, United Kingdom ; Thrombosis Research Institute, Bangalore, India.
authors.forename: Vijay
authors.initials: V
authors.lastname: Kakkar
authors.affiliation: The Mary and Garry Weston Molecular Immunology Laboratory, Thrombosis Research Institute, London, United Kingdom.
authors.forename: Xinjie
authors.initials: X
authors.lastname: Lu
mesh_terms: D000818:Animals; D050197:Atherosclerosis / Q000276:immunology* / Q000517:prevention & control*; D001426:Bacterial Proteins / Q000276:immunology*; D023521:Chlamydophila Infections; D016993:Chlamydophila pneumoniae / Q000276:immunology* / Q000472:pathogenicity*; D005434:Flow Cytometry; D007114:Immunization; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D010455:Peptides / Q000276:immunology* / Q000627:therapeutic use*
chemical_list: D001426:Bacterial Proteins; D010455:Peptides