A imunização com a proteína recombinante P21 diminui a carga parasitária e reduz a fibrose no coração dos animais infectados por trypanosoma cruzi.

Abstract

Trypanosoma cruzi, the etiological agent of Chagas disease, is widely distributed in nature, circulating between its hosts, triatomine bugs and wild mammals; it can naturally be transmitted to humans resulting in heart disease parasite-induced. During the cell invasion process, many interactions occur between the molecules from parasite surface or secreted receptors of the host cell. In this context, our research group identified in T. cruzi, a new protein of 21 kDa, involved in the cellular invasion, named P21. The recombinant form of native P21 (rP21) is used in studies on biological aspects of T. cruzi, providing elucidation of its function in protozoan infection. The present study aimed to investigate different strategies of immunization using rP21 in mice infected or not by T. cruzi to understand the interaction of this protein with their immune system, as well as to identify an immunization schedule that could reduce the fibrosis caused by the chronic infection and promote the preservation of cardiac tissue. This study showed that immunization with the rP21 protein associated with Freud's Adjuvant was able to control parasitemia in the acute phase, increased the immune system cell populations, followed by reduction of parasitic burden on cardiac tissue. In addition, a robust humoral immune response was observed, characterized by the production of anti-rP21 IgG2a antibodies that promoted decreased deposition of collagen fibers in cardiac tissue.