Mice immunized with either recombinant proteins or plasmid DNA were infected with blood trypomastigotes. The recombinant protein-immunized mice showed a variable reduction in peak parasitemia, and most died by day 60. Only the pBKTcSPR-immunized mice exhibited a significant reduction in peak parasitemia and survived the lethal challenge. DNA-based immunization with DNA coding for the repeats
domain of TcSP is a good candidate for the development of a vaccine against experimental T. cruzi infection. Chagas disease, caused by Trypanosoma cruzi, continues to be a major health problem in South and Central America, although the estimated number of infected people has fallen from approximately 20 million in 1981 to approximately 10 million in 2009 due to the implementation of vector control measures and
this website safer blood transfusions [1, 2]. Urbanization and migratory population movements from endemic countries have led to diagnosis of the disease even in nonendemic areas [3]. Although the transmission of this disease has diminished recently [4, find more 5], it is still a major problem, and currently, there are neither effective drugs nor vaccines for the treatment or prevention of the disease. The infection results in an acute parasitemic phase, followed by a chronic indeterminate phase during which parasitemia is generally undetectable and most patients remain asymptomatic. Approximately 30% of individuals in the chronic indeterminate phase progress to a chronic symptomatic phase involving severe cardiomyopathy or Lumacaftor gastrointestinal pathology. Several studies have examined
the protective roles of antibodies [6], Th1-type cytokines [7, 8] and cytotoxic T cells (CTL) [9, 10] in experimental models. A better understanding of the host immune response to parasite antigens will allow the development of effective vaccines to control T. cruzi infection. Towards this goal, a number of parasite antigens have been tested for their effectiveness in controlling parasite infection, including cruzipain [11], trans-sialidase (TS) [12], amastigote surface protein-2 [13], trypomastigote surface antigen-1 [14] and paraflagellar rod protein [15], among others. These antigens are located on the parasite surface and induce strong cellular and humoral responses during infection in mice. The T. cruzi genome contains 1430 gene members of the TS superfamily [16]. Members of the TS superfamily show at least 30–40% homology with the unique TS enzyme sequence. The importance of TS enzymatic activity for T. cruzi virulence [17, 18] and the large number of TS homologues suggest that this gene family may be involved in mechanisms of immune escape in the murine model of Chagas disease [19].