1B). IL-4/IL-10 cytokines became dominant in vaccinated mice. The tissue parasitism, inflammation, and fibrosis in heart and skeletal muscle mass of TcVac2-vaccinated chronic mice were undetectable by histological techniques. In comparison, mice injected with vector or cytokines only responded toT. cruziby elicitation of a mixed (type 1/type 2) antibody, T cell and cytokine response, and exhibited prolonged parasite burden and immunopathology in the myocardium. == Conclusion == TcVac2-induced activation of type 1 antibody and lymphocyte responses provided resistance to acuteT. cruziinfection, and consequently, prevented the evolution of chronic immunopathology associated with parasite persistence in chagasic hearts. == Author Summary == Trypanosoma cruzi, a parasitic protozoan, is the etiologic agent of Chagas disease. Chagas disease is the most common cause of congestive heart failure related deaths Rabbit polyclonal to DPPA2 among young adults in the endemic areas of South and Central America and Mexico. Vaccine development against Chagas disease has been dramatically limited because of extensive debate around the mechanisms involved in this pathology. It is now accepted that the presence of parasites in cardiac tissue is necessary to initiate and maintain the inflammatory responses and that therapeutic treatments or vaccines aimed at eliminatingT. cruziwould limit or prevent the progression of chronic chagasic cardiomyopathy. In the present study, we have tested the protecting efficacy of a multi-component heterologous DNA-prime/protein-boost vaccine TcVac2 in a murine model ofT. cruziinfection. Immunization of mice with TcVac2 induced potent antibody, CD8+T cell and cytokine responses that provided protection from acute parasitemia and chronic parasite persistence and immunopathology in chagasic mice in comparison to unvaccinated mice. == Introduction == Trypanosoma cruzi, a parasitic protozoan, is the etiologic agent of Chagas disease. Chagas disease is the most common cause of congestive heart failure related deaths among young adults in the endemic areas of South and Central America and Mexico[1]. It has also become an important health issue in the United States and Succinyl phosphonate trisodium salt Europe due to large level migration of Latin Americans over the last few decades[2]. No vaccines are currently available. Several investigators have documented that Succinyl phosphonate trisodium salt protecting immune mechanisms againstT. cruziare constituted of a strong lytic antibody response, cytotoxic T lymphocytes activity, and Th1 cytokines[3][7]Towards identifying the potential vaccine candidates,T. cruzitransfectants expressing ovalbumin (OVA, model antigen) in different cellular compartments were developed. Immunological studies in mice infected with OVA-transfectants suggested that parasite GPI-anchored (released by default in host cell cytoplasm) and secreted proteins were capable of entering the class I and class II pathways of antigen presentation and eliciting antibody and T cell responses, and, thus, would be the best choice as vaccine candidates[8]. Accordingly, several GPI-anchored proteins ofT. cruzihave been recognized, and their immunogenic potential examined in mice. Many of the selected antigenic targets provided variable degree of resistance toT. cruzias DNA or protein vaccine[5],[9][13](reviewed in[14][16]). In parallel with the efforts towards identification of vaccine[9]candidates, the development of methods to Succinyl phosphonate trisodium salt enhance the protecting efficacy of subunit vaccines againstT. cruzihas been the primary focus of research for several years. These include the use of adjuvants, e.g. saponin with GP90[17], alum with GP82[9], IL-12 and CpGODN with cruzipain[12][18],[19]and IL-12 and GMCSF in numerous studies (reviewed in[20]). Others have used attenuated strain of Salmonella[21]adenovirus[22],[23]for antigen delivery, or a heterologous prime-boost protocols[24],[25]to enhance the selected candidates efficacy againstT. cruzi. We have employed an unbiased computational/bioinformatics approach for screening theT. cruzisequence database and identification of potential vaccine candidates[26]. A strategic analysis of the sequence database led to selection of 71 candidates that were unique toT. cruzi, but not the users of the trans-sialidase, mucin or other large gene families, and exhibited multiple motifs/characteristics of secreted or GPI-anchored proteins. Of these, eight candidates (TcG1, TcG2, TcG3, TcG4, TcG5, TcG6, TcG7, and TcG8 [TcG1-TcG8]) were phylogenetically conserved in clinically important strains ofT. cruzi, expressed in the infective and intracellular stages of the parasite[26], and elicited varying level of lytic antibody response and Th1 cytokines (IFN-), a property associated with immune control ofT. cruzi,in immunized mice. TcG1-, TcG2-, and TcG4-encoded antigens were expressed Succinyl phosphonate trisodium salt around the plasma membrane of the mammalian stages ofT. cruzi(trypomastigote/amastigote) and elicited significant levels of anti-parasite lytic antibody responses.