title: Induction of neonatal tolerance to oxidized lipoprotein reduces atherosclerosis in ApoE knockout mice.
abstract: BACKGROUND
  In the course of atherosclerosis, humans and apolipoprotein (apoE) Knockout (KO) mice exhibit an active cell-mediated and humoral immune process, both at the systemic level and within atheromata. Low density lipoproteins (LDL) infiltrate the vascular wall, where they are oxidatively modified. This oxidative modification may generate new epitopes for which tolerance is not achieved during ontogenesis. Such epitopes could constitute new targets for autoreactive immune responses that may have a physiopathological role in disease development.
  
  
  METHODS
  Exposing mice to high dose of antigens during thymic T-cell education induces immunological tolerance to the administered antigens. We injected newborn apoE KO mice with oxidized LDL. They were fed a cholesterol-rich diet and aortic atherosclerosis, cell-mediated immune response, and T-cell repertoire were analyzed after 5 months.
  
  
  RESULTS
  Injection of oxidized LDL at birth reduced not only the immune response to oxidized LDL, but also susceptibility to atherosclerosis in apoE mice. Injection of oxidized LDL induced T-cell tolerance due to clonal deletion, rather than anergy of the reactive T cells. The T-cell repertoire of apoE KO mice was affected by the development of the disease, whereas tolerization normalized it.
  
  
  CONCLUSIONS
  This study demonstrates that the immune response against oxidized LDL has a deleterious role in atherogenesis and that a fine-tuning of this response could modify the course of the disease.
authors.affiliation: Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Nicoletti
authors.forename: G
authors.initials: G
authors.lastname: Paulsson
authors.forename: G
authors.initials: G
authors.lastname: Caligiuri
authors.forename: X
authors.initials: X
authors.lastname: Zhou
authors.forename: G K
authors.initials: GK
authors.lastname: Hansson
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology; D001011:Aorta / Q000187:drug effects / Q000473:pathology; D001057:Apolipoproteins E / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D001161:Arteriosclerosis / Q000139:chemically induced / Q000235:genetics / Q000276:immunology* / Q000503:physiopathology; D002478:Cells, Cultured; D002791:Cholesterol, Dietary / Q000008:administration & dosage / Q000494:pharmacology; D017637:Clonal Deletion / Q000276:immunology; D004036:Diet, Atherogenic; D004198:Disease Susceptibility; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D005260:Female; D017353:Gene Deletion; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology*; D007136:Immunoglobulins / Q000097:blood / Q000276:immunology; D008077:Lipoproteins, LDL / Q000008:administration & dosage / Q000276:immunology*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D015703:Antigens, CD; D001057:Apolipoproteins E; D002791:Cholesterol, Dietary; D018984:Epitopes, T-Lymphocyte; D007136:Immunoglobulins; D008077:Lipoproteins, LDL; D011948:Receptors, Antigen, T-Cell; C099252:oxidized low density lipoprotein