Transcriptomic analysis of benznidazole-resistant and susceptible Trypanosoma cruzi populations

Treatment of Refractory Mucosal Leishmaniasis Is Associated with Parasite Overexpression of HSP70 and ATPase and Reduced Host Hydrogen Peroxide Production (Brief Report)

BACKGROUND

Mucosal leishmaniasis (ML) is a deforming type of American Tegumentary Leishmaniasis caused by Leishmania (Viannia) braziliensis that frequently does not respond to treatment. Despite its relapsing clinical course, few parasites are usually found in mucosal lesions. Host and parasite factors may be responsible for this paradox in the pathogenesis of the disease, allowing for both a low parasite burden and the inability of the host to clear and eliminate the disease.

METHODS AND RESULTS

In this work, we present a clinical case of relapsing ML that was treated for 25 years without success with SbV, N-methyl glucamine, sodium stibogluconate, amphotericin B deoxycholate, gabromycin, antimonial plus thalidomide, liposomal amphotericin B, Leishvacin (a vaccine made in Brazil) and miltefosine. In a comparative analysis using nanoscale liquid chromatography coupled with tandem mass spectrometry of protein extracts of L. (V.) braziliensis promastigotes isolated from the patient and from the reference strain (MHOM/BR/94/M15176), we observed increases in ATPase and HSP70 protein levels in the parasite. We also observed an impairment in the production of hydrogen peroxide by peripheral mononuclear blood monocytes (PBMCs), as assessed by the horseradish peroxidase-dependent oxidation of phenol red.

CONCLUSIONS

We hypothesise that these parasite molecules may be linked to the impairment of host parasiticidal responses, resulting in Leishmania persistence in ML patients.

In Vitro Antiprotozoal Activity of Schinus molle Extract, Partitions, and Fractions against Trypanosoma cruzi

Chagas disease, caused by the protozoan Trypanosoma cruzi, represents an important and worldwide public health issue, particularly in Latin America. Limitations of conventional treatment with benznidazole and nifurtimox underscore the urgent need for new therapeutic strategies for this disease. Schinus molle, a tree used in traditional medicine for various ailments, has demonstrated promising antiparasitic activity. The in vitro anti-T. cruzi activity of Schinus molle crude methanol extract, partitions, and fractions, as well as their cytotoxicity in Vero cells and Artemia salina, and hemolytic activity in human erythrocytes were assessed. Most of the extracts possessed anti-T. cruzi effects, with Sm-CF3 being the fraction with the highest activity (IC50 = 19 µg/mL; SI = 6.8). Gas chromatography-mass spectrometry analysis identified 20 compounds, with fatty acyls comprising the predominant chemical class (55%). We also identified the antiparasitic compounds cis-5,8,11,14,17-eicosapentaenoic acid and trans-Z-α-bisabolene epoxide, suggesting their potential contribution to the observed anti-T. cruzi activity. In conclusion, our findings support the therapeutic potential of S. molle as a source of novel antiparasitic agents against T. cruzi.

New drug discovery strategies for the treatment of benznidazole-resistance in Trypanosoma cruzi, the causative agent of Chagas disease

INTRODUCTION

Benznidazole, the drug of choice for treating Chagas Disease (CD), has significant limitations, such as poor cure efficacy, mainly in the chronic phase of CD, association with side effects, and parasite resistance. Understanding parasite resistance to benznidazole is crucial for developing new drugs to treat CD.

AREAS COVERED

Here, the authors review the current understanding of the molecular basis of benznidazole resistance. Furthermore, they discuss the state-of-the-art methods and critical outcomes employed to evaluate the efficacy of potential drugs against T. cruzi, aiming to select better compounds likely to succeed in the clinic. Finally, the authors describe the different strategies employed to overcome resistance to benznidazole and find effective new treatments for CD.

EXPERT OPINION

Resistance to benznidazole is a complex phenomenon that occurs naturally among T. cruzi strains. The combination of compounds that inhibit different metabolic pathways of the parasite is an important strategy for developing a new chemotherapeutic protocol.

Metallomics: An Essential Tool for the Study of Potential Antiparasitic Metallodrugs

Metallomics is an emerging area of omics approaches that has grown enormously in the past few years. It integrates research related to metals in biological systems, in symbiosis with genomics and proteomics. These omics approaches can provide in-depth insights into the mechanisms of action of potential metallodrugs, including their physiological metabolism and their molecular targets. Herein, we review the most significant advances concerning cellular uptake and subcellular distribution assays of different potential metallodrugs with activity against Trypanosma cruzi, the protozoan parasite that causes Chagas disease, a pressing health problem in high-poverty areas of Latin America. Furthermore, the first multiomics approaches including metallomics, proteomics, and transcriptomics for the comprehensive study of potential metallodrugs with anti-Trypanosoma cruzi activity are described.

Subunit nanovaccine elicited T cell functional activation controls Trypanosoma cruzi mediated maternal and placental tissue damage and improves pregnancy outcomes in mice

This study investigated a candidate vaccine effect against maternal Trypanosoma cruzi (Tc) infection and improved pregnancy outcomes. For this, TcG2 and TcG4 were cloned in a nanoplasmid optimized for delivery, antigen expression, and regulatory compliance (nano2/4 vaccine). Female C57BL/6 mice were immunized with nano2/4, infected (Tc SylvioX10), and mated 7-days post-infection to enable fetal development during the maternal acute parasitemia phase. Females were euthanized at E12-E17 (gestation) days. Splenic and placental T-cell responses were monitored by flow cytometry. Maternal and placental/fetal tissues were examined for parasites by qPCR and inflammatory infiltrate by histology. Controls included age/immunization-matched non-pregnant females. Nano2/4 exhibited no toxicity and elicited protective IgG2a/IgG1 response in mice. Nano2/4 signaled a splenic expansion of functionally active CD4+ effector/effector memory (Tem) and central memory (Tcm) cells in pregnant mice. Upon challenge infection, nano2/4 increased the splenic CD4+ and CD8+T cells in all mice and increased the proliferation of CD4+Tem, CD4+Tcm, and CD8+Tcm subsets producing IFNγ and cytolytic molecules (PRF1, GZB) in pregnant mice. A balanced serum cytokines/chemokines response and placental immune characteristics indicated that pregnancy prevented the overwhelming damaging immune response in mice. Importantly, pregnancy itself resulted in a significant reduction of parasites in maternal and fetal tissues. Nano2/4 was effective in arresting the Tc-induced tissue inflammatory infiltrate, necrosis, and fibrosis in maternal and placental tissues and improving maternal fertility, placental efficiency, and fetal survival. In conclusion, we show that maternal nano2/4 vaccination is beneficial in controlling the adverse effects of Tc infection on maternal health, fetal survival, and pregnancy outcomes.

From Benznidazole to New Drugs: Nanotechnology Contribution in Chagas Disease

Chagas disease is a neglected tropical disease caused by the protozoan Trypanosoma cruzi. Benznidazole and nifurtimox are the two approved drugs for their treatment, but both drugs present side effects and efficacy problems, especially in the chronic phase of this disease. Therefore, new molecules have been tested with promising results aiming for strategic targeting action against T. cruzi. Several studies involve in vitro screening, but a considerable number of in vivo studies describe drug bioavailability increment, drug stability, toxicity assessment, and mainly the efficacy of new drugs and formulations. In this context, new drug delivery systems, such as nanotechnology systems, have been developed for these purposes. Some nanocarriers are able to interact with the immune system of the vertebrate host, modulating the immune response to the elimination of pathogenic microorganisms. In this overview of nanotechnology-based delivery strategies for established and new antichagasic agents, different strategies, and limitations of a wide class of nanocarriers are explored, as new perspectives in the treatment and monitoring of Chagas disease.