Performance Assessment of ELISA Using the Specific Antigen Tc323 for the Diagnosis of Chronic Chagas Disease.

In the chronic phase of Chagas disease (CCD), diagnosis relies on detecting specific IgG antibodies due to the low or absent presence of the parasite in human blood. However, the performance of current serological tests is highly variable, lacking a "" assay with 100% sensitivity and specificity, which challenges the exploration of new biomarkers. In the present study, we evaluated the diagnostic accuracy of an optimized ELISA using the predicted immunogenic domains (called TcD3 and TcD6) of Tc323, a protein highly conserved among strains but absent in other clinically significant parasites such as .

The Kinetoplastid-Specific Protein TcCAL1 Plays Different Roles During Differentiation and Host-Cell Invasion in .

In the pathogen , the calcium ion (Ca) regulates key processes for parasite survival. However, the mechanisms decoding Ca signals are not fully identified or understood. Here, we investigate the role of a hypothetical Ca-binding protein named TcCAL1 in the life cycle of .

differentiation of epimastigotes into metacyclic trypomastigotes using a biphasic medium.

The pathogen differentiates from epimastigotes (E) into infective metacyclic trypomastigotes (MTs) to invade the mammalian cell. This process, called metacyclogenesis, is mimicked in vitro by nutrient starvation or incubation with minimal media. Here, we describe an alternative protocol for metacyclogenesis by incubating E forms in a biphasic medium supplemented with human blood.

Recombinant antibody against Trypanosoma cruzi from patients with chronic Chagas heart disease recognizes mammalian nervous system.

Background: To deeply understand the role of antibodies in the context of Trypanosoma cruzi infection, we decided to characterize A2R1, a parasite antibody selected from single-chain variable fragment (scFv) phage display libraries constructed from B cells of chronic Chagas heart disease patients.

Methods: Immunoblot, ELISA, cytometry, immunofluorescence and immunohistochemical assays were used to characterize A2R1 reactivity. To identify the antibody target, we performed an immunoprecipitation and two-dimensional electrophoresis coupled to mass spectrometry and confirmed A2R1 specific interaction by producing the antigen in different expression systems.

Production of Recombinant Trypanosoma cruzi Antigens in Leishmania tarentolae.

Trypanosomatids are unicellular organisms that colonize a wide diversity of environments and hosts. For instance, Trypanosoma cruzi is a human pathogen responsible for Chagas diseases, while Leishmania tarentolae infects amphibians and became a biotechnological tool suitable for recombinant protein expression. T.

Transcriptome-wide analysis of the Trypanosoma cruzi proliferative cycle identifies the periodically expressed mRNAs and their multiple levels of control.

Trypanosoma cruzi is the protozoan parasite causing American trypanosomiasis or Chagas disease, a neglected parasitosis with important human health impact in Latin America. The efficacy of current therapy is limited, and its toxicity is high. Since parasite proliferation is a fundamental target for rational drug design, we sought to progress into its understanding by applying a genome-wide approach.

Characterization of TcCYC6 from Trypanosoma cruzi, a gene with homology to mitotic cyclins.

Trypanosoma cruzi, the etiologic agent of Chagas disease, is a protozoan parasite with a life cycle that alternates between replicative and non-replicative forms, but the components and mechanisms that regulate its cell cycle are poorly described. In higher eukaryotes, cyclins are proteins that activate cyclin-dependent kinases (CDKs), by associating with them along the different stages of the cell cycle. These cyclin-CDK complexes exert their role as major modulators of the cell cycle by phosphorylating specific substrates.

Colchicine treatment reversibly blocks cytokinesis but not mitosis in Trypanosoma cruzi epimastigotes.

This work analyzes the effect of the alkaloid colchicine on the growth of Trypanosoma cruzi epimastigotes, using immunofluorescence microscopy and flow cytometry techniques. We found that colchicine reversibly inhibited cytokinesis but not synthesis or segregation of nuclear and kinetoplastid DNA, in a concentration-dependent manner. We showed that, once colchicine was removed from the growth medium, cytokinesis was restored but abnormal segregation of kinetoplasts and nuclei generated zoids and parasites with two nuclei and one kinetoplast, among other aberrant cells.

Functional characterization of TcCYC2 cyclin from Trypanosoma cruzi.

In eukaryotes, an oscillating network of protein kinase activities drives the order and timing of the cell cycle progression. Complexes formed by cyclins associated to cyclin-dependent kinases (CDKs) are the central components of this network. Cyclins act as the activating subunits and their abundance is regulated by different mechanisms in order to promote or prevent kinase activity.

Identification of an atypical peptidyl-prolyl cis/trans isomerase from trypanosomatids.

The parvulin family of peptidyl-prolyl cis/trans isomerases (PPIases) catalyzes the cis/trans isomerization of the peptide bonds preceding Pro residues. Eukaryotic parvulin-type PPIases have been shown to be involved in cell proliferation and cell cycle progression. Here we present the biochemical and molecular characterization of a novel multi-domain parvulin-type PPIase from the human pathogenic Trypanosoma cruzi, annotated as TcPar45.

In vitro anti-parasitic activity of Cyclosporin A analogs on Trypanosoma cruzi.

Cyclosporin A (CsA) nonimmunosuppressive analogs were evaluated against Trypanosoma cruzi and on TcCyP19, a cyclophilin of 19 kDa. Two out of eight CsA analogs, H-7-94 and F-7-62 showed the best anti-parasitic effects on all in vitro assays. Their IC(50) values were 0.