Deficiency of antigen-presenting cell invariant chain reduces atherosclerosis in mice.
Circulation
; 122(8): 808-20, 2010 Aug 24.
Article
em En
| MEDLINE
| ID: mdl-20697023
ABSTRACT
BACKGROUND:
Adaptive immunity and innate immunity play important roles in atherogenesis. Invariant chain (CD74) mediates antigen-presenting cell antigen presentation and T-cell activation. This study tested the hypothesis that CD74-deficient mice have reduced numbers of active T cells and resist atherogenesis. METHODS ANDRESULTS:
In low-density lipoprotein receptor-deficient (Ldlr(-/-)) mice, CD74 deficiency (Ldlr(-/-)Cd74(-/-)) significantly reduced atherosclerosis and CD25(+)-activated T cells in the atheromata. Although Ldlr(-/-)Cd74(-/-) mice had decreased levels of plasma immunoglobulin (Ig) G1, IgG2b, and IgG2c against malondialdehyde-modified LDL (MDA-LDL), presumably as a result of impaired antigen-presenting cell function, Ldlr(-/-)Cd74(-/-) mice showed higher levels of anti-MDA-LDL IgM and IgG3. After immunization with MDA-LDL, Ldlr(-/-)Cd74(-/-) mice had lower levels of all anti-MDA-LDL Ig isotypes compared with Ldlr(-/-) mice. As anticipated, only Ldlr(-/-) splenocytes responded to in vitro stimulation with MDA-LDL, producing Th1/Th2 cytokines. Heat shock protein-65 immunization enhanced atherogenesis in Ldlr(-/-) mice, but Ldlr(-/-) Cd74(-/-) mice remained protected. Compared with Ldlr(-/-) mice, Ldlr(-/-)Cd74(-/-) mice had higher anti-MDA-LDL autoantibody titers, fewer lesion CD25(+)-activated T cells, impaired release of Th1/Th2 cytokines from antigen-presenting cells after heat shock protein-65 stimulation, and reduced levels of all plasma anti-heat shock protein-65 Ig isotypes. Cytofluorimetry of splenocytes and peritoneal cavity cells of MDA-LDL- or heat shock protein-65-immunized mice showed increased percentages of autoantibody-producing marginal zone B and B-1 cells in Ldlr(-/-)Cd74(-/-) mice compared with Ldlr(-/-) mice.CONCLUSIONS:
Invariant chain deficiency in Ldlr(-/-) mice reduced atherosclerosis. This finding was associated with an impaired adaptive immune response to disease-specific antigens. Concomitantly, an unexpected increase in the number of innate-like peripheral B-1 cell populations occurred, resulting in increased IgM/IgG3 titers to the oxidation-specific epitopes.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Antígenos de Diferenciação de Linfócitos B
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Antígenos de Histocompatibilidade Classe II
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Aterosclerose
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Células Apresentadoras de Antígenos
Limite:
Animals
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article