Trypanosoma cruzi, the agent of Chagas disease, accumulates polyphosphate (polyP) and Ca2+ inside acidocalcisomes. The alkalinization of this organelle stimulates polyP hydrolysis and Ca2+ release. Here, we report that histidine ammonia lyase (HAL), an enzyme that catalyzes histidine deamination with production of ammonia (NH3) and urocanate, is responsible for acidocalcisome alkalinization. Histidine addition to live parasites expressing …
Drug Target Validation of the Protein Kinase AEK1, Essential for Proliferation, Host Cell Invasion, and Intracellular Replication of the Human Pathogen Trypanosoma cruzi
Protein phosphorylation is involved in several key biological roles in the complex life cycle of Trypanosoma cruzi, the etiological agent of Chagas disease, and protein kinases are potential drug targets. Here, we report that the AGC essential kinase 1 (TcAEK1) exhibits a cytosolic localization and a higher level of expression in the replicative stages of …
Trypanosoma cruzi Letm1 is involved in mitochondrial Ca 2+ transport, and is essential for replication, differentiation, and host cell invasion
Leucine zipper-EF-hand containing transmembrane protein 1 (Letm1) is a mitochondrial inner membrane protein involved in Ca2+ and K+ homeostasis in mammalian cells. Here, we demonstrate that the Letm1 orthologue of Trypanosoma cruzi, the etiologic agent of Chagas disease, is important for mitochondrial Ca2+ uptake and release. The results show that both mitochondrial Ca2+ influx and efflux are reduced in …
Immune exhaustion in chronic Chagas disease: Pro-inflammatory and immunomodulatory action of IL-27 in vitro
In chronic Chagas disease, Trypanosoma cruzi-specific T-cell function decreases over time, and alterations in the homeostatic IL-7/IL-7R axis are evident, consistent with a process of immune exhaustion. IL-27 is an important immunoregulatory cytokine that shares T-cell signaling with IL-7 and other cytokines of the IL-12 family and might be involved in the transcriptional regulation of …
Mitochondrial Pyruvate Carrier Subunits Are Essential for Pyruvate-Driven Respiration, Infectivity, and Intracellular Replication of Trypanosoma cruzi
Pyruvate is the final metabolite of glycolysis and can be converted into acetyl coenzyme A (acetyl-CoA) in mitochondria, where it is used as the substrate for the tricarboxylic acid cycle. Pyruvate availability in mitochondria depends on its active transport through the heterocomplex formed by the mitochondrial pyruvate carriers 1 and 2 (MPC1/MPC2). We report here …
High variation in immune responses and parasite phenotypes in naturally acquired Trypanosoma cruzi infection in a captive non-human primate breeding colony in Texas, USA
Trypanosoma cruzi, the causative agent of human Chagas disease, is endemic to the southern region of the United States where it routinely infects many host species. The indoor/outdoor housing configuration used in many non-human primate research and breeding facilities in the southern of the USA provides the opportunity for infection by T. cruzi and thus …
Deletion of a Golgi protein in Trypanosoma cruzi reveals a critical role for Mn2+ in protein glycosylation needed for host cell invasion and intracellular replication
Trypanosoma cruzi is a protist parasite and the causative agent of American trypanosomiasis or Chagas disease. The parasite life cycle in its mammalian host includes an intracellular stage, and glycosylated proteins play a key role in host-parasite interaction facilitating adhesion, invasion and immune evasion. Here, we report that a Golgi-localized Mn2+-Ca2+/H+ exchanger of T. cruzi …
Reduced Trypanosoma cruzi-specific humoral response and enhanced T cell immunity after treatment interruption with benznidazole in chronic Chagas disease
Background: Interruption of benznidazole therapy due to the appearance of adverse effects, which is presumed to lead to treatment failure, is a major drawback in the treatment of chronic Chagas disease. Methods: Trypanosoma cruzi-specific humoral and T cell responses, T cell phenotype and parasite load were measured to compare the outcome in 33 subjects with chronic Chagas …
Strain-specific genome evolution in Trypanosoma cruzi, the agent of Chagas disease
The protozoan Trypanosoma cruzi almost invariably establishes life-long infections in humans and other mammals, despite the development of potent host immune responses that constrain parasite numbers. The consistent, decades-long persistence of T. cruzi in human hosts arises at least in part from the remarkable level of genetic diversity in multiple families of genes encoding the …
The Inositol Pyrophosphate Biosynthetic Pathway of Trypanosoma cruzi
Inositol phosphates (IPs) are phosphorylated derivatives of myo-inositol involved in the regulation of several cellular processes through their interaction with specific proteins. Their synthesis relies on the activity of specific kinases that use ATP as phosphate donor. Here, we combined reverse genetics and liquid chromatography coupled to mass spectrometry (LC-MS) to dissect the inositol phosphate …







