title: DNA immunization with the ribosomal P2beta gene of Trypanosoma cruzi fails to induce pathogenic antibodies.
abstract: Patients with chronic Chagas' heart disease (cChHD) develop a strong IgG response against the C-terminal region of the Trypanosoma cruzi ribosomal P2beta protein (TcP2beta). These antibodies have been shown to exert an in vitro chronotropic effect on cardiocytes through stimulation of the beta1-adrenergic receptor (beta1-AR). Moreover, the presence of antibodies recognizing the TcP2beta C-terminus was associated with cardiac alterations in mice immunized with the corresponding recombinant protein. Here, we demonstrate that DNA immunization could be used to modulate the specificity of the anti-TcP2beta humoral response in order to avoid the production of pathogenic antibodies. After DNA injection, we detected IgG antibodies that were directed only to internal epitopes of the TcP2beta molecule and that did not exert anti-beta1-AR functional activity, measured as an increase in intracellular cAMP levels of transfected COS-7 cells. Accordingly, DNA-immunized mice did not present electrocardiographic alterations. These data demonstrate that anti-TcP2beta antibodies elicited by DNA immunization are completely different in their specificity and functional activity from those produced during T. cruzi infection.
authors.affiliation: Laboratorio de Biología Molecular de la Enfermedad de Chagas, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI/CONICET), Vuelta de Obligado 2490, Buenos Aires, 1428, Argentina.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Levitus
authors.forename: Vanina
authors.initials: V
authors.lastname: Grippo
authors.forename: Vivian
authors.initials: V
authors.lastname: Labovsky
authors.forename: Sergio
authors.initials: S
authors.lastname: Ghio
authors.forename: Mireille
authors.initials: M
authors.lastname: Hontebeyrie
authors.forename: Mariano J
authors.initials: MJ
authors.lastname: Levin
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology*; D019556:COS Cells; D016054:DNA, Protozoan / Q000276:immunology*; D004562:Electrocardiography; D018604:Epitope Mapping; D006801:Humans; D007074:Immunoglobulin G; D051379:Mice; D008809:Mice, Inbred C3H; D010750:Phosphoproteins / Q000737:chemistry / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D012269:Ribosomal Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D014162:Transfection; D014349:Trypanosoma cruzi / Q000235:genetics / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D016054:DNA, Protozoan; D007074:Immunoglobulin G; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; D012269:Ribosomal Proteins; C031937:phosphoprotein P2, ribosomal