Trypanosoma cruzi Secreted Cyclophilin TcCyP19 as an Early Marker for Trypanocidal Treatment Efficiency.

Cyclophilins (CyPs) are a family of enzymes involved in protein folding. Trypanosoma cruzi, the causative agent of Chagas disease, has a 19-kDa cyclophilin, TcCyP19, that was found to be secreted in parasite stages of the CL Brener clone and recognized by sera from T. cruzi-infected mice and patients. The levels of specific antibodies against TcCyP19 in T. cruzi-infected mice and subjects before and after drug treatment were measured by an in-house enzyme linked immunosorbent assay (ELISA). Mice in the acute and chronic phase of infection, with successful trypanocidal treatments, showed significantly lower anti-TcCyP19 antibody levels than untreated mice. In children and adults chronically infected with T. cruzi, a significant decrease in the anti-TcCyP19 titers was observed after 12 months of etiological treatment. This decrease was maintained in adult chronic patients followed-up 30-38 months post-treatment. These results encourage further studies on TcCyP19 as an early biomarker of trypanocidal treatment efficiency.

Circulating Cytokine and Chemokine Profiles of Trypanosoma cruzi-Infected Women During Pregnancy and Its Association With Congenital Transmission.

BACKGROUND: Trypanosoma cruzi, the causative agent of Chagas disease, can be transmitted to the offspring of infected women, which constitutes an epidemiologically significant parasite transmission route in nonendemic areas. It is relevant to evaluate differentially expressed factors in T. cruzi-infected pregnant women as potential markers of Chagas congenital transmission. METHODS: Circulating levels of 12 cytokines and chemokines were measured by enzyme-linked immunosorbent assay or cytometric bead array in T. cruzi-infected and uninfected pregnant women in their second trimester of pregnancy and control groups of T. cruzi-infected and uninfected nonpregnant women. RESULTS: Trypanosoma cruzi-infected women showed a proinflammatory Th1-biased profile, with increased levels of tumor necrosis factor (TNF)-α, interleukin (IL)-12p70, IL-15, and monokine induced by interferon-gamma (MIG). Uninfected pregnant women presented a biased response towards Th2/Th17/Treg profiles, with increased plasma levels of IL-5, IL-6, IL-1ß, IL-17A, and IL-10. Finally, we identified that high parasitemia together with low levels of TNF-α, IL-15, and IL-17, low TNF-α/IL-10 ratio, and high IL-12p70 levels are factors associated with an increased probability of Chagas congenital transmission. CONCLUSIONS: Trypanosoma cruzi-infected pregnant women who did not transmit the infection to their babies exhibited a distinct proinflammatory cytokine profile that might serve as a potential predictive marker of congenital transmission.

Trypanosoma cruzi infection in Cyclophilin D deficient mice.

Trypanosoma cruzi is the causative agent of Chagas disease, which is endemic in Latin America and around the world through mother to child transmission. The heart is the organ most frequently affected in the chronic stage of the human infection and depends on mitochondria for the required energy for its activity. Cyclophilins are involved in protein folding and the mitochondrial isoform, Cyclophilin D (CyPD), has a crucial role in the opening of the mitochondrial permeability transition pore. In the present study, we infected CyPD deficient mice, with ablation of the Ppif gene, with T. cruzi parasites and the course of the infection was analyzed. Parasite load, quantified by PCR, was significantly lower in skeletal and cardiac tissues of Ppif-/- mice compared to wild type mice. In vitro cultured cardiomyocytes and macrophages from mice lacking CyPD exhibited lower percentage of infected cells and number of intracellular parasites than those observed for wild type mice. Although histopathological analysis of heart and mRNA of heart cytokines showed differences between T. cruzi-infected mice compared to the uninfected animals, no significant differences were found mice due to the ablation of the Ppif gene. Our results suggest that cells deficient for mitochondrial CyPD, inhibited for the mitochondrial membrane potential collapse, reduces the severity of parasite aggression and spread of cellular infection.

Trypanosoma cruzi Infection at the Maternal-Fetal Interface: Implications of Parasite Load in the Congenital Transmission and Challenges in the Diagnosis of Infected Newborns.

Trypanosoma cruzi is the protozoan unicellular parasite that causes Chagas disease. It can be transmitted from infected mothers to their babies via the connatal route, thus being able to perpetuate even in the absence of Triatomine insect vectors. Chagas disease was originally endemic in Central and South America, but migration of infected women of childbearing age has spread the T. cruzi congenital infection to non-endemic areas like North America, Europe, Japan, and Australia. Currently, 7 million people are affected by this infection worldwide. This review focuses on the relevance of the T. cruzi parasite levels in different aspects of the congenital T. cruzi infection such as the mother-to-child transmission rate, the maternal and fetal immune response, and its impact on the diagnosis of infected newborns. Improvements in detection of this parasite, with tools that can be easily adapted to be used in remote rural areas, will make the early diagnosis of infected children possible, allowing a prompt trypanocidal treatment and avoiding the current loss of opportunities for the diagnosis of 100% of T. cruzi congenitally infected infants.

A Functional Analysis of the Cyclophilin Repertoire in the Protozoan Parasite Trypanosoma Cruzi.

Trypanosoma cruzi is the etiological agent of Chagas disease. It affects eight million people worldwide and can be spread by several routes, such as vectorborne transmission in endemic areas and congenitally, and is also important in non-endemic regions such as the United States and Europe due to migration from Latin America. Cyclophilins (CyPs) are proteins with enzymatic peptidyl-prolyl isomerase activity (PPIase), essential for protein folding in vivo. Cyclosporin A (CsA) has a high binding affinity for CyPs and inhibits their PPIase activity. CsA has proved to be a parasiticidal drug on some protozoa, including T. cruzi. In this review, we describe the T. cruzi cyclophilin gene family, that comprises 15 paralogues. Among the proteins isolated by CsA-affinity chromatography, we found orthologues of mammalian CyPs. TcCyP19, as the human CyPA, is secreted to the extracellular environment by all parasite stages and could be part of a complex interplay involving the parasite and the host cell. TcCyP22, an orthologue of mitochondrial CyPD, is involved in the regulation of parasite cell death. Our findings on T. cruzi cyclophilins will allow further characterization of these processes, leading to new insights into the biology, the evolution of metabolic pathways, and novel targets for anti-T. cruzi control.

A homolog of cyclophilin D is expressed in Trypanosoma cruzi and is involved in the oxidative stress-damage response.

Mitochondria have an important role in energy production, homeostasis and cell death. The opening of the mitochondrial permeability transition pore (mPTP) is considered one of the key events in apoptosis and necrosis, modulated by cyclophilin D (CyPD), a crucial component of this protein complex. In Trypanosoma cruzi, the protozoan parasite that causes Chagas disease, we have previously described that mitochondrial permeability transition occurs after oxidative stress induction in a cyclosporin A-dependent manner, a well-known cyclophilin inhibitor. In the present work, a mitochondrial parasite cyclophilin, named TcCyP22, which is homolog to the mammalian CyPD was identified. TcCyP22-overexpressing parasites showed an enhanced loss of mitochondrial membrane potential and loss of cell viability when exposed to a hydrogen peroxide stimulus compared with control parasites. Our results describe for the first time in a protozoan parasite that a mitochondrial cyclophilin is a component of the permeability transition pore and is involved in regulated cell death induced by oxidative stress.

Oxidative stress damage in the protozoan parasite Trypanosoma cruzi is inhibited by Cyclosporin A.

Cyclosporin A (CsA) specifically inhibits the mitochondrial permeability transition pore (mPTP). Opening of the mPTP, which is triggered by high levels of matrix [Ca2+] and/or oxidative stress, leads to mitochondrial dysfunction and thus to cell death by either apoptosis or necrosis. In the present study, we analysed the response of Trypanosoma cruzi epimastigote parasites to oxidative stress with 5 mm H2O2, by studying several features related to programmed cell death and the effects of pre-incubation with 1 µ m of CsA. We evaluated TcPARP cleavage, DNA integrity, cytochrome c translocation, Annexin V/propidium iodide staining, reactive oxygen species production. CsA prevented parasite oxidative stress damage as it significantly inhibited DNA degradation, cytochrome c translocation to cytosol and TcPARP cleavage. The calcein-AM/CoCl2 assay, used as a selective indicator of mPTP opening in mammals, was also performed in T. cruzi parasites. H2O2 treatment decreased calcein fluorescence, but this decline was partially inhibited by pre-incubation with CsA. Our results encourage further studies to investigate if there is a mPTP-like pore and a mitochondrial cyclophilin involved in this protozoan parasite.