Major Trypanosoma cruzi antigenic determinant in Chagas' heart disease shares homology with the systemic lupus erythematosus ribosomal P protein epitope.
A Trypanosoma cruzi lambda gt11 cDNA clone, JL5, expressed a recombinant protein which was found to react predominantly with chronic Chagas' heart disease sera. The cloned 35-residue-long peptide was identified as the carboxyl-terminal portion of a T. cruzi ribosomal P protein. The JL5 13 carboxyl-terminal residues shared a high degree of homology with the systemic lupus erythematosus (SLE) ribosomal P protein epitope. Synthetic peptides comprising the 13 (R-13), 10 (R-10), and 7 (R-7) carboxyl-terminal residues of the JL5 protein were used to study, by enzyme-linked immunosorbent assay, the specificity of the Chagas' disease anti-JL5 and SLE anti-P antibodies. The R-13 peptide defined a linear antigenic determinant of the JL5 recombinant protein. As was proved for JL5, R-13 defined antibody specificities which were significantly increased in chronic Chagas' heart disease patients. Only SLE anti-P positive sera were found to react with JL5 and R-13. Fine epitope mapping showed that Chagas' disease anti-JL5 and SLE anti-P antibodies define similar epitopes within the R-13 peptide. The binding of the SLE sera to JL5 was completely blocked by the R-13 peptide, indicating that the shared specificity between anti-JL5 and anti-P autoantibodies was exclusively limited to the conserved linear epitope(s) within the R-13 peptide. The prevalence of high anti-R-13 antibody titers in Chagas' heart disease patients supports the hypothesis that postulates the existence of autoimmune disorders in Chagas' heart disease.
Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET), Buenos Aires, Argentina.
E A
EA
Mesri
G
G
Levitus
M
M
Hontebeyrie-Joskowicz
G
G
Dighiero
M H
MH
Van Regenmortel
M J
MJ
Levin
D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology*; D002598:Chagas Cardiomyopathy / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000150:complications / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D012269:Ribosomal Proteins; D012689:Sequence Homology, Nucleic Acid; D014349:Trypanosoma cruzi / Q000235:genetics / Q000276:immunology*; D001616:beta-Galactosidase / Q000276:immunology
D000953:Antigens, Protozoan; D000939:Epitopes; D010750:Phosphoproteins; D011994:Recombinant Proteins; D012269:Ribosomal Proteins; C035690:ribosomal phosphoprotein P1; D001616:beta-Galactosidase