and Protein Expression Profile

Background. Trypanosoma cruzi–infected outbred hamsters reproduce the range of different outcomes ofChagas disease noted in humans.We testedwhethermyocarditis, itsmediators, andmyocardial protein expression are related to the severity of the acute phase of T. cruzi infection in the hamster model. Methods. Myocardium left ventricles (LVs) obtained from Syrian hamsters infected with T. cruzi were collected 21 days after infection.Myocarditis and theT. cruzinest/antigen areawere analyzed by histological andmorphometric analysis. Cytokine and chemokine messenger RNA (mRNA) expression was analyzed using real-time reverse-transcriptase polymerase chain reaction. Differentially expressed proteins were identified by 2-dimensional electro-phoresis, followed by mass spectrometry. Results. While in the acute phase of infection, 50 % of animals displayed weight loss and signs of acute-phase infection (hereafter referred to as “acute-phase signs ” [APS]) (e.g., lethargy, vomiting, and diarrhea). Both theT. cruzi nest/antigen area and the expression of interferon-, tumor necrosis factor–, interleukin-10, and CCL3mRNAwere significantly increased in the LVs of animals with APS, compared with the LVs of animals without APS. Animals with APS, those without APS, and uninfected animals demonstrated distinct myocardial expression of contractile, stress response, and metabolism proteins. Conclusions. The distinct outcomes of acute T. cruzi infection in Syrian hamsters are related to cardiac parasit