The obligate intracellular protozoan Trypanosoma cruzi causes Chagas' disease, a leading cause of morbidity and mortality in Latin America. It is a major economic burden in Latin America and in developed counties such as the USA, largely due to the approximately 30% of chagasic patients who progress to chronic Chagas cardiomyopathy. Chronic Chagas heart disease is characterized by generalized focal inflammation, fibrosis, arrhythmias, congestive heart failure and sudden death. There are no drugs capable of ameliorating chronic Chagas cardiomyopathy. Heart transplant is the only cure but it is not practical due to the difficulty is securing hearts. The goal of this proposal is to determine the optimal dose and kinetic regimen of a novel lead compound that, in accord with preliminary results, effectively block T cruzi entry into cardiomyocytes and cardiac fibroblasts, reversing cardiac parasitism, inflammation and fibrosis in a mouse model of chronic Chagas cardiomyopathy. The concept underlying the novel antitrypanosomal compound is similar to that antiviral Maraviroc, which works by blocking HIV entry into CD4 lymphocytes. Maraviroc is currently used to treat AIDS. We propose to determine 1) dose regimen of biologic entry cell inhibitor that optimally reduces cardiac parasitism in mice with chronic cardiomyopathy; 2) dose regimen of a synthetic peptide modeled on the biologic, which optimally reduces cardiac parasitism in mice with chronic cardiomyopathy; 3) whether swapping peptide motifs in the lead antitrypanosomal compound improves therapeutic efficiency; and 4) mechanisms underlying differential interaction of synthetic peptides with entry receptors on cardiac cells in stimulating either host cell invasion or trophic response that improves therapeutic efficiency. The project wil use biochemical, parasitological, genetic, cytochemical and non-invasive diagnostic approaches and highlights the translational value of understanding molecular mechanisms governing entry of intracellular microbes into their habitat.
Chagas' disease, caused by the parasite Trypanosoma cruzi, devastates more than 8 million people in the Americas. Chronic cardiomyopathy is major cause of mortality in endemic areas and is already a significant economic problem in the United States and other developed countries, estimated to cost approximately $7.19 billion per year. This research will elucidate a novel strategy, based on the inhibition of parasite entry into cardiac cells, aimed to reduce or eliminate cardiac parasitism, which is the main trigger of the cardiomyopathy. Thus, the project may lead to a drug for the treatment of cardiomyopathy in Chagas for which there is no cure except for heart transplant, which is not practical due to the difficulty in securing hearts for transplant.