XXXVII Reunion Anual de la Sociedad Argentina de Investigaciones en Bioquimica y Biologia Molecular

GRIPPO VANINA; SERGIO GHIO; P. LOPEZ BERGAMI; LEVIN MJ; GABRIELA LEVITUS

Congreso; XXXVII Reunion Anual de la Sociedad Argentina de Investigaciones en Bioquimica y Biologia Molecular; 2001

The characterization of naturally acquired antibodies against the acidic T. cruzi ribosomal P proteins suggests that the chronic infection is able to induce a functional autoimmune response against cardiac receptors through a mechanism of molecular mimicry. On the other hand, we have recently finished the cloning and expression of all the ribosomal P proteins and the highly acidic GARP antigen. We wanted to assess the effect induced by immunization with this type of proteins. DNA immunization is a simple methodology which allows the long-term expression of the antigen in the host's muscular tissue. It has been proposed that this strategy resembles the antigenic presentation occurring in the natural infection, and more appropriate for us, considering that P proteins and GARP are intracellular. Mice were immunized with DNA constructs expressing the T. cruzi P ribosomal proteins and GARP in host's muscular tissue. The specificity of  the antibodies and the isotipic profile induced were different than those from the natural infection and from immunization with recombinant proteins. Interestingly, immunization with recombinants corresponding to the T. cruzi ribosomal P proteins produced significant modifications in the electrocardiogram of immunized mice, while DNA immunization did not induce changes. These studies provide evidence that DNA vaccination with these antigens does not induce an antigenic presentation similar to that of the natural infection, where as immunization with recombinants does.