Molecular mimicry between the immunodominant ribosomal protein P0 of Trypanosoma cruzi and a functional epitope on the human beta 1-adrenergic receptor.
J Exp Med
; 182(1): 59-65, 1995 Jul 01.
Article
en En
| MEDLINE
| ID: mdl-7790824
ABSTRACT
Sera from chagasic patients possess antibodies recognizing the carboxy-terminal part of the ribosomal P0 protein of Trypanosoma cruzi and the second extracellular loop of the human beta 1-adrenergic receptor. Comparison of both peptides showed that they contain a pentapeptide with very high homology (AESEE in P0 and AESDE in the human beta 1-adrenergic receptor). Using a competitive immunoenzyme assay, recognition of the peptide corresponding to the second extracellular loop (H26R) was inhibited by both P0-14i (AAAESEEEDDDDDF) and P0-beta (AESEE). Concomitantly, recognition of P0-beta was inhibited with the H26R peptide. Recognition of P0 in Western blots was inhibited by P0-14i, P0-beta, and H26R, but not by a peptide corresponding to the second extracellular loop of the human beta 2-adrenergic receptor or by an unrelated peptide. Autoantibodies affinity purified with the immobilized H26R peptide were shown to exert a positive chronotropic effect in vitro on cardiomyocytes from neonatal rats. This effect was blocked by both the specific beta 1 blocker bisoprolol and the peptide P0-beta. These results unambiguously prove that T. cruzi is able to induce a functional autoimmune response against the cardiovascular human beta 1-adrenergic receptor through a molecular mimicry mechanism.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Fosfoproteínas
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Proteínas Ribosómicas
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Autoantígenos
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Enfermedades Autoinmunes
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Trypanosoma cruzi
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Cardiomiopatía Chagásica
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Epítopos Inmunodominantes
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Receptores Adrenérgicos beta 1
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Imitación Molecular
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Antígenos de Protozoos
Tipo de estudio:
Etiology_studies
Límite:
Animals
Idioma:
En
Año:
1995
Tipo del documento:
Article