Among the different infective stages that Trypanosoma cruzi employs to invade cells, extracellular amastigotes (EAs) have recently gained attention by our group. This is true primarily because these amastigotes are able to infect cultured cells and animals, establishing a sustainable infective cycle. EAs are thus an excellent means of adaptation and survival for T. cruzi, whose different infect...

Obligate intracellular pathogens satisfy their nutrient requirements by coupling to host metabolic processes, often modulating these pathways to facilitate access to key metabolites. Such metabolic dependencies represent potential targets for pathogen control, but remain largely uncharacterized for the intracellular protozoan parasite and causative agent of Chagas disease, Trypanosoma cruzi. Pe...

Leishmania is a protozoan parasite that causes serious morbidity and mortality in humans worldwide. The ability of these parasites to survive within the phagolysosomes of mammalian macrophages is dependent on the developmental regulation of a variety of genes. Identifying genomic sequences that are preferentially expressed during the parasite's intracellular growth would provide new insights ab...

Infection with lesion-derived Leishmania mexicana amastigotes inhibited LPS-induced IL-12 production by mouse bone marrow-derived macrophages. This effect was associated with expression of cysteine peptidase B (CPB) because amastigotes of CPB deletion mutants had limited ability to inhibit IL-12 production, whereas preincubation of cells with a CPB inhibitor, cathepsin inhibitor IV, was able to...

BACKGROUND Leishmaniasis is a parasitic disease associated with extensive mortality and morbidity. The treatment for leishmaniasis is currently based on pentavalent antimonials and amphotericin B; however, these drugs result in numerous adverse side effects. Natural compounds have been used as novel treatments for parasitic diseases. In this paper, we evaluated the effect of (-)-epigallocatechi...

Current therapy for leishmaniasis is not satisfactory. We describe the in vitro antiproliferative effects of new thiadiazine derivatives against Leishmania amazonensis. The compounds were found to be active against the amastigote form of the parasite, inhibiting parasite growing, from 10 to 89%, at a concentration of 100 ng/ml. This activity suggests that thiadiazine derivatives could be consid...

In this study we examined enhancement effects of Artemisinin plus Glucantime and shark cartilage extract, on promastigotes and amastigotes of L.infantum in in vitro condition.The toxicity of artemisinin, glucantime and shark cartilage extract on the L. infantum promastigotes and amastigote-infected macrophages was evaluated using MTT assay. The role of these drugs in inducing apoptosis in proma...

Maesabalide III (MB-III), an oleane triterpene saponin isolated from the Vietnamese plant Maesa balansae, is a new antileishmanial lead compound whose activity against Leishmania donovani (MHOM/ET/67/L82) in groups of five golden hamsters was evaluated after administration of a single subcutaneous dose on either day 1 (prophylactic treatment) or day 28 (curative treatment) after infection. Lipo...

Chagas, the disease bearing his name remains one of the most neglected topical diseases in the world. Trypanosoma cruzi, the causative agent of Chagas disease, is a protozoan parasite which has become unable to synthesize purines and pteridines instead salvaging them from its human host. It is mainly transmitted by the feces of the Kissing bug, but it is also spread by organ transplant, blood t...

We have raised monoclonal antibodies (mAbs) directed towards amastigote forms of Trypanosoma cruzi, and shown that mAbs ID9 and 4B9 are carbohydrate while mAb 4B5 activity is resistant to periodate oxidation of the antigen. Here we used an ELISA to quantitate and compare the expression of surface epitopes on fixed parasites among different parasite isolates. The expression of markers varied amo...