Navegando por Autor "Reis, Levi Eduardo Soares"

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    Activity of the sesquiterpene lactone goyazensolide against Trypanosoma cruzi in vitro and in vivo.
    (2020) Milagre, Matheus Marques; Branquinho, Renata Tupinambá; Gonçalves, Maíra Fonseca; Assis, Gabriela Maíra Pereira de; Oliveira, Maykon Tavares de; Reis, Levi Eduardo Soares; Guimarães, Dênia Antunes Saúde; Lana, Marta de
    Background: The current drugs for Chagas disease treatment present several limitations Methods: The sesquiterpene lactone goyazensolide (GZL) was evaluated regarding to cytotoxicity and trypanocidal activity against amastigotes, selectivity index (SI) in vitro, acute toxicity and anti-Trypanosoma cruzi activity in vivo. Results: The in vitro cytotoxicity in H9c2 cells was observed at doses >250 ng mL−1 of GZL and the SI were of 52.82 and 4.85 (24 h) and of 915.00 and 41.00 (48 h) for GZL and BZ, respectively. Nephrotoxicity and hepatotoxicity were not verified. Treatment with GZL of mice infected with CL strain led to a significant decrease of parasitaemia and total survival at doses of 1 and 3 mg kg−1 day−1 by oral and IV, respectively. This last group cured 12.5% of the animals (negativation of HC, PCR, qPCR and ELISA). Animals infected with Y strain showed significant decrease of parasitaemia and higher negativation in all parasitological tests in comparison to BZ and control groups, but were ELISA reactive, as well as the BZ group, but mice treated with 5.0 mg kg−1 day−1 by oral were negative in parasitological tests and survived. Conclusion: GZL was more active against T. cruzi than benznidazole in vitro and presented important therapeutic activity in vivo in both T. cruzi strains.
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    Association between mast cells, tissue remodelation and parasite burden in the skin of dogs with visceral leishmaniasis.
    (2017) Cardoso, Jamille Mirelle de Oliveira; Ker, Henrique Gama; Soares, Rodrigo Dian de Oliveira Aguiar; Moreira, Nádia das Dores; Mathias, Fernando Augusto Siqueira; Reis, Levi Eduardo Soares; Roatt, Bruno Mendes; Vieira, Paula Melo de Abreu; Vital, Wendel Coura; Carneiro, Cláudia Martins; Reis, Alexandre Barbosa
    Canine visceral leishmaniosis (CVL) is a zoonosis of major public health impact caused by organisms of the genus Leishmania which is transmitted to human and animals by phlebotomine sand flies. The skin is the first point of contact with Leishmania parasites for sandy fly vectors and it is considered an important reservoir compartment in infected dogs. The aim of this study was to determine the main histophatologic alterations in ear skin of dogs naturally infected by Leishmania infantum with different clinical status and different degrees of parasitism. Therefore, thirty-four dogs naturally infected with L. infantum were grouped according to their clinical status in asymptomatic (AD, n =11), oligosymptomatic (OD, n=11) and symptomatic dogs (SD, n=12) as well as their degrees of parasite load in the skin as low (LP, n=11), median (MP, n= 11) and high (HP, n=12) parasitism. Additionally, ten dogs were used as control (CD, n =10). At necropsy, skin samples were collected for further histological and parasitological analysis. The OD and SD groups presented higher parasite burden than AD group. The inflammation was higher in SD group when compared to OD and AD. The LP, MP and HP groups showed an increasing inflammatory process, indicating that a great parasite load is accompanied by a major inflammatory process in the skin. The number of mast cells was higher in the OD and LP groups than CD group, suggesting that these cells may be involved in tissue remodeling, since that an increase of type III collagen fibers and decrease type I collagen fibers were observed in these groups. Taken together, our results enable a better understanding of the alterations in skin of CVL dogs and consequently new insights about the pathogenesis of CVL.
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    Canine visceral leishmaniasis : incidence and risk factors for infection in a cohort study in Brazil.
    (2013) Vital, Wendel Coura; Reis, Alexandre Barbosa; Reis, Levi Eduardo Soares; Braga, Samuel Leôncio; Roatt, Bruno Mendes; Soares, Rodrigo Dian de Oliveira Aguiar; Marques, Marcos José; Veloso, Vanja Maria; Carneiro, Mariângela
    Zoonotic visceral leishmaniasis in Brazil is caused by Leishmania infantum parasites andis transmitted by sand flies of the Phlebotominae family. Dogs are the main urban reser-voirs and represent the major source of contagion for the vectors. Studies have shown thatmost infected dogs are polymerase chain reaction-positive months before seroconversion.Herein, we describe a cohort study designed to identify the incidence of and risk factorsfor L. infantum infection as detected by polymerase chain reaction-restriction fragmentlength polymorphism. To determine the risk factors for infection, we conducted a base-line canine survey (n = 1443) from which dogs were selected for the cohort study (n = 282)involving three evaluations over the course of a 26-month follow-up period. Serology,molecular tests, and a structured questionnaire were used. The risk factors for infectionwere identified by means of the Cox regression model. The overall infection incidencewas 5.8 per 100 dog-months (95% confidence interval 5.1–6.5). Increased risk of infec-tion was associated with the presence of previous cases of canine visceral leishmaniasis inthe domiciles (hazard ratio [HR] 1.4; 95% confidence interval [CI] 1.1–1.8) and unplasteredhouse walls (HR 3.6; 95% CI 1.6–8.1). These risk factors suggest that insecticide spraying incracks and crevices in unplastered walls can reduce biting rates within and around homes.Furthermore, our results demonstrate that the Visceral Leishmaniasis Control and Surveil-lance Program should adopt environmental management measures in homes with previouscases of canine visceral leishmaniasis, because these homes are more likely to maintain thetransmission cycle.
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    Cell immune response in mice skin stimulated with different adjuvants by intradermal route.
    (2022) Mathias, Fernando Augusto Siqueira; Cardoso, Jamille Mirelle de Oliveira; Reis, Levi Eduardo Soares; Souza, Juliana Vitoriano de; Moreira, Nádia das Dores; Ostolin, Thais Lopes Valentim Di Paschoale; Brito, Rory Cristiane Fortes de; Soares, Rodrigo Dian de Oliveira Aguiar; Vieira, Paula Melo de Abreu; Carneiro, Cláudia Martins; Roatt, Bruno Mendes; Reis, Alexandre Barbosa
    Adjuvants act in the innate immunity and, when combined to vaccine antigens, can produce a more intense response, improving the antigen presentation, directing the immune system, excellent for new vaccine formulations. This study evaluated the use of the intradermal route and the immune response triggered by a single dose of the adjuvants Aluminum Hydroxide (Al(OH)3 ), Montanide Pet Gel A (MPGA), Glucopyranosyl Lipid A Stable Emulsion (GLA-SE), and Resiquimod (R-848) in the mice skin. As control mice received sterile saline. MPGA and GLA-SE led to cell recruitment when compared with control group, with intense presence of neutrophils in first 12 hours, replaced by macrophages after 168 hours. R-848 and Al(OH)3 showed similar cell recruitment profiles. Regarding cytokine production, groups that received MPGA and GLA-SE produced high levels of IL-6, TNF-α, and IFN-γ. R-848 and Al(OH)3 groups displayed similar profile of cytokine production only at the first hour. Our results suggest that the intradermal route is efficient inducing immune system activation and GLA-SE was promising adjuvants for a type 1 immune response vaccine.
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    Chimeric vaccines designed by immunoinformatics-activated polyfunctional and memory T cells that trigger protection against experimental visceral leishmaniasis.
    (2020) Brito, Rory Cristiane Fortes de; Ruiz, Jeronimo Conceição; Cardoso, Jamille Mirelle de Oliveira; Ostolin, Thais Lopes Valentim Di Paschoale; Reis, Levi Eduardo Soares; Mathias, Fernando Augusto Siqueira; Soares, Rodrigo Dian de Oliveira Aguiar; Roatt, Bruno Mendes; Oliveira, Rodrigo Corrêa de; Resende, Daniela de Melo; Reis, Alexandre Barbosa
    Many vaccine candidates against visceral leishmaniasis (VL) have been proposed; however, to date, none of them have been efficacious for the human or canine disease. On this basis, the design of leishmaniasis vaccines has been constantly changing, and the use of approaches to select specific epitopes seems to be crucial in this scenario. The ability to predict T cell-specific epitopes makes immunoinformatics an even more necessary approach, as in VL an efficient immune response against the parasite is triggered by T lymphocytes in response to Leishmania spp. immunogenic antigens. Moreover, the success of vaccines depends on the capacity to generate long-lasting memory and polyfunctional cells that are able to eliminate the parasite. In this sense, our study used a combination of different approaches to develop potential chimera candidate vaccines against VL. The first point was to identify the most immunogenic epitopes of Leishmania infantum proteins and construct chimeras composed of Major histocompatibility complex (MHC) class I and II epitopes. For this, we used immunoinformatics features. Following this, we validated these chimeras in a murine model in a thorough memory study and multifunctionality of T cells that contribute to a better elucidation of the immunological protective mechanisms of polyepitope vaccines (chimera A and B) using multicolor flow cytometry. Our results showed that in silico-designed chimeras can elicit polyfunctional T cells producing T helper (Th)1 cytokines, a strong immune response against Leishmania antigen, and the generation of central and effector memory T cells in the spleen cells of vaccinated animals that was able to reduce the parasite burden in this organ. These findings contribute two potential candidate vaccines against VL that can be used in further studies, and help in this complex field of vaccine development against this challenging parasite.
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    Clinical forms of canine visceral Leishmaniasis in naturally Leishmania infantum – infected dogs and related myelogram and hemogram changes.
    (2013) Nicolato, Roney Luiz de Carvalho; Abreu, Raquel Trópia de; Roatt, Bruno Mendes; Soares, Rodrigo Dian de Oliveira Aguiar; Reis, Levi Eduardo Soares; Carvalho, Maria das Graças; Carneiro, Cláudia Martins; Giunchetti, Rodolfo Cordeiro; Bouillet, Leoneide Érica Maduro; Lemos, Denise da Silveira; Vital, Wendel Coura; Reis, Alexandre Barbosa
    Hematological analysis has limited applications for disease diagnosis in Leishmania infantum–infected dogs, but it can be very important in evaluating the clinical forms of the disease and in understanding the evolution of canine visceral leishmaniasis (CVL) pathogenesis. Recently, we demonstrated that alterations in leucopoiesis and erythropoiesis are related to clinical status and bone marrow parasite density in dogs naturally infected by L. infantum. To further characterize these alterations, we evaluated the association between the hematological parameters in bone marrow and peripheral blood alterations in groups of L. infantum–infected dogs: asymptomatic I (AD-I: serum negative/PCR+), asymptomatic II (AD-II: serum positive), oligosymptomatic (OD), and symptomatic (SD). Results were compared with those from noninfected dogs (NID). The SD group was found to present a decrease in erythropoietic lineage with concomitant reductions in erythrocytes, hemoglobin, and hematocrit parameters, resulting in anemia. The SD group also had increased neutrophils and precursors and decreased band eosinophils and eosinophils, leading to peripheral blood leucopenia. In the AD-II group, lymphocytosis occurred in both the peripheral blood and the bone marrow compartments. The SD group exhibited lymphocytosis in the bone marrow, with lymphopenia in the peripheral blood. In contrast, the AD-I group, showed no significant changes suggestive of CVL, presenting normal counts in bone marrow and peripheral blood. Our results showed for the first time that important changes in hematopoiesis and hematological parameters occur during ongoing CVL in naturally infected dogs, mainly in symptomatic disease. Taken together, our results based on myelogram and hemogram parameters enable better understanding of the pathogenesis of the anemia, lymphocytosis, and lymphopenia, as well as the leucopenia (eosinopenia and monocytopenia), that contribute to CVL prognosis.
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    Comparative analysis of real-time PCR assays in the detection of canine visceral leishmaniasis.
    (2018) Nunes, Juliana Barbosa; Vital, Wendel Coura; Colombo, Fabio Antonio; Baêta, Frederico José Moreira; Pinheiro, Aimara da Costa; Roatt, Bruno Mendes; Reis, Levi Eduardo Soares; Reis, Alexandre Barbosa; Marques, Marcos José
    Dogs are important hosts and reservoirs of leishmaniasis, a disease caused by protozoan parasites from the genus Leishmania, affecting ~12 million people worldwide. The detection of visceral leishmaniasis (VL) in dogs by real-time PCR (qPCR) may improve on diagnosis, but the different qPCR methods available for Leishmania DNA detection have not been established as routine in diagnostic tools and/or epidemiologic studies for canine VL. Here, we compared three qPCR assays (DNApol, Linj31, and LDON) in the detection of VL by Leishmania infantum in spleen (n = 48; 7), skin (n = 48; 7), and whole blood (n = 44; 7) samples from serologically positive and negative dogs, respectively. Overall, the DNApol performed better than the Linj31 and LDON assays in the detection of positive samples in all tissues tested, yielding from 66.7 to 100.0% of positivity for both skin and spleen samples. For spleen samples, we observed no statistically significant differences between positive detection by the LDON and DNApol assays. Whole blood samples yielded the lowest rates of positive detection, regardless of the qPCR assay used. In contrast, positive detection of Leishmania DNA was as efficient from skin samples using the DNApol assay as from spleen samples using either the DNApol or the LDON assay. Although qPCR assays from skin samples may not be practical for use in the field, our study suggests that the DNApol and LDON assays from skin samples could be used in future to evaluate canine VL treatment in veterinary clinics.
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    Comparative evaluation of meglumine antimoniate encapsulated in a mixture of conventional and PEGylated liposomes and immunotherapy using an anti-canine IL-10 receptor-blocking monoclonal antibody on canine visceral leishmaniasis.
    (2022) Cardoso, Jamille Mirelle de Oliveira; Brito, Rory Cristiane Fortes de; Mathias, Fernando Augusto Siqueira; Reis, Levi Eduardo Soares; Vieira, João Filipe Pereira; Ostolin, Thais Lopes Valentim Di Paschoale; Andrade, Hélida Monteiro de; Ramos, Guilherme Santos; Frezard, Frederic; Soares, Rodrigo Dian de Oliveira Aguiar; Roatt, Bruno Mendes; Reis, Alexandre Barbosa
    This study compared the therapeutic potential of the chemotherapy using meglumine antimoniate encapsulated in a mixture of conventional and PEGylated liposomes (Nano Sbv ) and immunotherapy with anti-canine IL-10 receptor-blocking monoclonal antibody (Anti IL-10R) on canine visceral leishmaniasis (CVL). Twenty mongrel dogs naturally infected by L. infantum, displaying clinical signs of visceral leishmaniasis were randomly divided in two groups. In the first one, nine dogs received six intravenous doses of a mixture of conventional and PEGylated liposomes containing meglumine antimoniate at 6.5 mg Sb/kg/dose. In the second one, eleven dogs received two intramuscular doses of 4 mg of anti-canine IL-10 receptor-blocking monoclonal antibody. The animals were evaluated before (T0) and 30, 90, and 180 days after treatments. Our major results demonstrated that both treatments were able to maintain hematological and biochemical parameters, increase circulating T lymphocytes subpopulations, increase the IFN-γ producing T-CD4 lymphocytes, restore the lymphoproliferative capacity and improve the clinical status. However, although these improvements were observed in the initial post-treatment times, they did not maintain until the end of the experimental follow-up. We believe that the use of booster doses or the association of chemotherapy and immunotherapy (immunochemotherapy) is promising to improve the effectiveness of treating CVL for improving the clinical signs and possibly reducing the parasite burden in dogs infected with Leishmania infantum.
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    Comparison of capillary electrophoresis, AGE, and PAGE for MTHFR polymorphism analysis in FFPE cervical samples.
    (2018) Silva, Nayara Nascimento Toledo; Reis, Levi Eduardo Soares; Lima, Angélica Alves
    Background. Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism analysis could help in diagnosis, treatment, and prognosis of some pathologies, since it has been associated with the development of cardiovascular diseases, defects in neural tube formation, psychiatric disorders, and cancer. Polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP) is the most commonly used technique to analyze this polymorphism. Usually, RFLP products are evaluated by agarose gel electrophoresis (AGE) or polyacrylamide gel electrophoresis (PAGE). However, capillary electrophoresis (CE) may represent an alternative for MTHFR C677T polymorphism analysis by PCR-RFLP. Thus, the aim of this study was to compare CE, AGE, and PAGE to MTHFR C677T polymorphism analysis of Formalin-Fixed and Paraffin-Embedded (FFPE) cervical samples. Methods. 150 biopsy blocks of cervical samples were analyzed. MTHFR polymorphism was evaluated by PCR-RFLP, and the products generated were analyzed by CE, AGE, and PAGE. Concordance between the methods was evaluated by rate agreement, Kappa coefficient, and McNemars’s Test. Results. Eight samples (5.4%) showed discordant results according to CE and PAGE or AGE. Differences of CC and CT frequencies were observed between CE and AGE (p=0.016): CC genotype varied from 68.0% to 72.7%, and CT varied from 23.3% to 27.3%. Besides, Kappa coefficient between CE and AGE, or PAGE was very high (κ>0.81). Conclusion. Capillary electrophoresis presented high agreement with PAGE and AGE, and may be an accurate, safe, and quick alternative method for MTHFR polymorphism analysis.
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    Detecção de Leishmania por PCR e suas variações (seminested PCR e PCR em tempo real), em fragmentos de pele e de baço de cães com leishmaniose visceral.
    (Programa de Pós-Graduação em Ciências Farmacêuticas. CIPHARMA, Escola de Farmácia, Universidade Federal de Ouro Preto., 2013) Reis, Levi Eduardo Soares; Reis, Alexandre Barbosa; Vital, Wendel Coura
    A detecção do DNA de Leishmania spp, pela Reação em Cadeia da Polimerase (PCR) e suas variações, surgem como alternativas para o diagnóstico da LVC, por serem métodos altamente sensíveis e específicos. O objetivo deste trabalho foi comparar a PCR e suas variações (Seminested PCR e PCR em tempo real) utilizando amostras de pele e de baço de 60 cães soropositivos (RIFI e ELISA). Os animais foram agrupados considerando a forma clínica, sendo classificados como assintomáticos (CA; n=20), oligossintomáticos (CO; n= 22) e sintomáticos (CS; n= 18). Como controle negativo, foram utilizados fragmentos de três cães não infectados provenientes do canil da UFOP. O diagnóstico parasitológico, utilizado como padrão ouro, foi realizado por meio de duas metodologias: cultivo de aspirado medular em meio de cultura NNN/LIT e pela visualização direta de formas amastigotas do parasito em lâminas com imprints de pele e de baço. As análises moleculares foram realizadas utilizando iniciadores direcionados para a região conservada do minicírculo do kDNA de Leishmania – L150/L152 e LINR4/LIN17/LIN19 para as técnicas de PCRc e snPCR, respectivamente. Na qPCR foram utilizados iniciadores que amplificam o gene da DNA polimerase (DNA pol α) de L. infantum. De acordo com os testes parasitológicos 61,7% das amostras foram positivas. Nos fragmentos de pele, a sensibilidade da PCRc foi de 89,2%, já para a snPCR e qPCR foi de 86,5% e 97,3% respectivamente. VPP para a PCRc foi de 36,0%, snPCR de 35,3% e da qPCR foi 38,1%. O VPN foi de 93,6%, 92,1% e 98,3% pelas técnicas de PCRc, snPCR e qPCR respectivamente. Em amostras de baço, a sensibilidade da PCRc foi 81,1%, snPCR de 94,6% e de 100,0% pela qPCR. O VPP para a PCRc foi 33,9%, snPCR 37,4% e qPCR 38,7%. O VPN da PCRc foi de 89,3%, snPCR 96,7% e qPCR 100,0%. A positividade nos testes moleculares aumentou de acordo com a gravidade dos sinais clínicos. Foi observado que a qPCR apresentou os melhores resultados na pele e no baço devido a maior sensibilidade, VPP e VPN, em comparação as outras técnicas moleculares. Sendo assim, concluímos que a melhor técnica e tecido para o diagnóstico molecular da LVC é a qPCR de pele, devido à elevada sensibilidade e fácil obtenção da amostra biológica.
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    Dogs infected with the blood trypomastigote form of Trypanosomacruzi display an increase expression of cytokines and chemokines plusan intense cardiac parasitism during acute infection.
    (2014) Souza, Sheler Martins de; Vieira, Paula Melo de Abreu; Roatt, Bruno Mendes; Reis, Levi Eduardo Soares; Fonseca, Kátia da Silva; Nogueira, Nívia Carolina; Reis, Alexandre Barbosa; Tafuri, Washington Luiz; Carneiro, Cláudia Martins
    The recent increase in immigration of people from areas endemic for Chagas disease (Trypanosoma cruzi)to the United States and Europe has raised concerns about the transmission via blood transfusion andorgan transplants in these countries. Infection by these pathways occurs through blood trypomastigotes(BT), and these forms of T. cruzi are completely distinct of metacyclic trypomastigotes (MT), releasedby triatomine vector, in relation to parasite–host interaction. Thus, research comparing infection withthese different infective forms is important for explaining the potential impacts on the disease course.Here, we investigated tissue parasitism and relative mRNA expression of cytokines, chemokines, andchemokine receptors in the heart during acute infection by MT or BT forms in dogs. BT-infected dogspresented a higher cardiac parasitism, increased relative mRNA expression of pro-inflammatory andimmunomodulatory cytokines and of the chemokines CCL3/MIP-1 _, CCL5/RANTES, and the chemokinereceptor CCR5 during the acute phase of infection, as compared to MT-infected dogs. These results suggestthat infection with BT forms may lead to an increased immune response, as revealed by the cytokinesratio, but this kind of immune response was not able to control the cardiac parasitism. Infection with theMT form presented an increase in the relative mRNA expression of IL-12p40 as compared to that of IL-10or TGF- _1. Correlation analysis showed increased relative mRNA expression of IFN- _ as well as IL-10,which may be an immunomodulatory response, as well as an increase in the correlation of CCL5/RANTESand its CCR5 receptor. Our findings revealed a difference between inoculum sources of T. cruzi, as vectorialor transfusional routes of T. cruzi infection may trigger distinct parasite–host interactions during the acutephase, which may influence immunopathological aspects of Chagas disease.
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    Down regulation of IL-10 and TGF-β1 mRNA expression associated with reduced inflammatory process correlates with control of parasitism in the liver after treating L. infantum infected dogs with the LBMPL vaccine therapy.
    (2022) Roatt, Bruno Mendes; Cardoso, Jamille Mirelle de Oliveira; Brito, Rory Cristiane Fortes de; Reis, Levi Eduardo Soares; Moreira, Gabriel José Lucas; Vieira, Paula Melo de Abreu; Souza, Flávia Marques de; Lima, Wanderson Geraldo de; Soares, Rodrigo Dian de Oliveira Aguiar; Giunchetti, Rodolfo Cordeiro; Reis, Alexandre Barbosa
    The liver plays an important role in human and canine visceral leishmaniasis, then it is considered as target to understand the mechanisms involved in the parasite control and a parameter to assess therapeutic responses. In this sense, our study focuses on evaluating the major alterations in the liver by histological (morphometric parenchyma inflammation/semi-quantitative portal inflammation), immunohistochemical assays (parasitism), and qPCR (parasitism and cytokine gene expression) in Leishmania infantum naturally infected dogs and treated with LBMPL vaccine. Animals were divided in four groups: NI group (n = 5): uninfected and untreated dogs; INT group (n = 7): L. infantum-infected dogs and not treated; MPL group (n = 6): L. infantum-infected dogs that received only monophosphoryl lipid A adjuvant, and LBMPL group (n = 10): L. infantum-infected dogs that received treatment with the vaccine composed by L. braziliensis disrupted promastigotes associated with MPL adjuvant. Ninety days after the end of treatments, the dogs were euthanized, and the liver was collected for the proposed evaluations. Significantly lower portal inflammatory reactions, and lower parenchyma inflammation were observed in the LBMPL group compared to INT and MPL groups. iNOS mRNA expression was higher in LBMPL group and in contrast, IL-10 and TGF-β1 mRNA expression was lower in this group when compared to INT group. Immunohistochemical and qPCR analysis showed significant parasite load reduction in LBMPL group compared to INT and MPL animals. Our data suggest that in naturally Leishmania-infected dogs, LBMPL vaccine reduces the damage in the hepatic tissue, being able to attenuate the type 2 immune response. It could be associated with a marked reduction in the parasitism decreasing liver inflammation in treated dogs. Along with previously obtained data, our results suggest that LBMPL vaccine can significantly contribute to the therapy strategy for L. infantum infected dogs.
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    Evaluation of the anti-Trypanosoma cruzi activity in vitro and in vivo of silibinin and silibinin in association to benznidazole.
    (2020) Torchelsen, Fernanda Karoline Vieira da Silva; Silva, Thaila Martins; Milagre, Matheus Marques; Silva, Rafael Rodrigues; Reis, Levi Eduardo Soares; Branquinho, Renata Tupinambá; Silva, Glenda Nicioli da; Lana, Marta de
    Chagas disease (CD) is endemic in Latin America. Drugs available for its treatment are benznidazole (BZ)/nifurtimox (NF), both with low efficacy in the late infection and responsible for several side effects. Studies of new drugs for CD among natural products, and using drug combinations with BZ/NF are recommended. Silibinin (SLB) is a natural compound that inhibits the efflux pump (Pgp) of drugs in host cell membranes, causes death of trypanosomatids, has anti-inflammatory activity, and was never assayed against T. cruzi. Here, in vitro and in vivo activities of SLB, SLB+BZ, and BZ against T. cruzi Y strain were evaluated. Cytotoxicity of SLB in VERO cells by the MTT method revealed IC50 of 250.22 μM. The trypanocidal activity evaluated by resazurin method in epimastigotes showed that SLB 25 μM inhibited parasite growth. SLB IC50 and selectivity index (SI) for amastigote were 79.81 μM and 3.13, respectively. SLB100+BZ10 showed higher parasite inhibition (91.44%) than SLB or BZ. Swiss mice infected with Y strain were treated with SLB, SLB+BZ, and BZ. Parasitemia was evaluated daily and 90, 180, and 240 days after treatment in surviving animals by hemoculture, blood qPCR, and after euthanasia, by qPCR in heart tissue. SLB monotherapy was not able to control the parasitemia/mortality of the animals. Parasitological negativation of 85.7– 100% was observed in the experimental groups treated with SLB+BZ. Although SLB had shown activity against T. cruzi in vitro, it was not active in mice. Thus, the results of the therapeutic effect observed with SLB+BZ may be interpreted as a result from BZ action.
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    Histopathological changes in the gastrointestinal tract and systemic alterations triggered by experimental oral infection with Trypanosoma cruzi.
    (2020) Carvalho, Lívia Mendes; Carvalho, Thaís Vieira de; Ferraz, Aline Tonhela; Marques, Flávia de Souza; Roatt, Bruno Mendes; Fonseca, Kátia da Silva; Reis, Levi Eduardo Soares; Carneiro, Cláudia Martins; Vieira, Paula Melo de Abreu
    Chagas disease, caused by the protozoan Trypanosoma cruzi, is endemic in almost all countries of Latin America. In Brazil, oral infection is becoming the most important mechanism of transmission of the disease in several regions of the country. The gastrointestinal tract is the gateway for the parasite through this route of infection, however, little is known about the involvement of these organs related to oral route. In this sense, the present study evaluated the impact of oral infection on the digestive tract in mice infected by Berenice-78 (Be-78) T. cruzi strain, in comparison with the intraperitoneal route of infection. In this work, the intraperitoneal route group showed a peak of parasitemia similar to the oral route group, however the mortality rate among the orally infected animals was higher when compared to intraperitoneal route. By analyzing the frequency of blood cell populations, differences were mainly observed in CD4+ T lymphocytes, and not in CD8+, presenting an earlier reduction in the number of CD4+ T cells, which persisted for a longer period, in the animals of the oral group when compared with the intraperitoneal group. Animals infected by oral route presented a higher tissue parasitism and inflammatory infiltrate in stomach, duodenum and colon on the 28th day after infection. Therefore, these data suggest that oral infection has a different profile of parasitological and immune responses compared to intraperitoneal route, being the oral route more virulent and with greater tissue parasitism in organs of the gastrointestinal tract evaluated during the acute phase.
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    IL-10 receptor blockade controls the in vitro infectivity of Leishmania infantum and promotes a Th1 activation in PBMC of dogs with visceral leishmaniasis.
    (2021) Cardoso, Jamille Mirelle de Oliveira; Brito, Rory Cristiane Fortes de; Costa, Ana Flávia Pereira; Mathias, Fernando Augusto Siqueira; Reis, Levi Eduardo Soares; Vieira, João Filipe Pereira; Soares, Rodrigo Dian de Oliveira Aguiar; Reis, Alexandre Barbosa; Roatt, Bruno Mendes
    An important strategy to reduce the risk of visceral leishmaniasis (VL) in humans is to control the infection and disease progression in dogs, the domestic reservoir of Leishmania infantum parasites. Certain therapeutic strategies that modulate the host immune response show great potential for the treatment of experimental VL, restoring the impaired effector functions or decreasing host excessive responses. It is known that the overproduction of interleukin-10 (IL-10) promotes parasite replication and disease progression in human VL as well as in canine visceral leishmaniasis (CVL). Thus, in the present study we investigated the potential of the anticanine IL-10 receptor-blocking monoclonal antibody (Bloq IL-10R) to control and reduce in vitro infectivity of L. infantum and improve the ability of PBMC isolated from VL dogs to alter the lymphoproliferative response and intracytoplasmic cytokines. Overall, GFP+ Leishmania showed lower capacity of in vitro infectivity in the presence of Bloq IL-10R. Moreover, addition of Bloq IL-10R in cultured PBMC enhanced T-CD4 and CD8 proliferative response and altered the intracytoplasmic cytokine synthesis, reducing CD4+IL-4+ cells and increasing CD8+IFNγ+ cells after specific antigen stimulation in PBMC of dogs. Furthermore, we observed an increase of TNF-α levels in supernatant of cultured PBMC under IL-10R neutralizing conditions. Together, our findings are encouraging and reaffirm an important factor that could influence the effectiveness of immune modulation in dogs with VL and suggest that blocking IL-10R activity has the potential to be a useful approach to CVL treatment.
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    LBMPL vaccine therapy induces progressive organization of the spleen microarchitecture, improved Th1 adaptative immune response and control of parasitism in Leishmania infantum naturally infected dogs.
    (2022) Roatt, Bruno Mendes; Cardoso, Jamille Mirelle de Oliveira; Reis, Levi Eduardo Soares; Moreira, Gabriel José Lucas; Gonçalves, Letícia Captein; Marques, Flávia de Souza; Moreira, Nádia das Dores; Vieira, Paula Melo de Abreu; Soares, Rodrigo Dian de Oliveira Aguiar; Giunchetti, Rodolfo Cordeiro; Reis, Alexandre Barbosa
    The spleen plays a central role in human and canine visceral leishmaniasis, where the activation of the immune response occurs in one of the tissues where Leishmania infantum reproduces. Therefore, this organ is both a target to understand the mechanisms involved in the parasite control and a parameter for assessing the therapeutic response. In this sense, this study aimed to evaluate the main histological, immunological and parasitological aspects in the spleen of symptomatic dogs naturally infected by L. infantum treated with the therapeutic vaccine LBMPL. For this, dogs were divided into four groups: dogs uninfected and untreated (NI group); L. infantum-infected dogs that were not treated (INT group); L. infantum-infected dogs that received treatment only with monophosphoryl lipid A adjuvant (MPL group); and L. infantum-infected dogs that received treatment with the vaccine composed by L. braziliensis promastigote proteins associated with MPL adjuvant (LBMPL group). Ninety days after the therapeutics protocol, the dogs were euthanized and the spleen was collected for the proposed evaluations. Our results demonstrated a reduction of hyperplasia of red pulp and follicular area of white pulp, increased mRNA expression of IFN-γ, TNF-α, IL-12 and iNOS, and decreased IL-10 and TGF-β1, and intense reduction of splenic parasitism in dogs treated with the LBMPL vaccine. These results possibly suggest that the pro-inflammatory environment promoted the progressive organization of the splenic architecture favoring the cellular activation, with consequent parasite control. Along with previously obtained data, our results propose the LBMPL vaccine as a possible treatment strategy for canine visceral leishmaniasis (CVL).
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    Lychnopholide in PLA-PEG nanocapsules cures infection by drug resistant Trypanosoma cruzi strain in acute and chronic phases.
    (2020) Branquinho, Renata Tupinambá; Mello, Carlos Geraldo Campos de; Oliveira, Maykon Tavares de; Reis, Levi Eduardo Soares; Vieira, Paula Melo de Abreu; Guimarães, Dênia Antunes Saúde; Mosqueira, Vanessa Carla Furtado; Lana, Marta de
    Chagas disease remains neglected, and current chemotherapeutics present severe limitations. Lychnopholide (LYC) at low doses loaded in polymeric poly(d,l-lactide)-block-polyethylene glycol (PLA-PEG) nanocapsules (LYC-PLA-PEG-NC) exhibits anti-Trypanosoma cruzi efficacy in mice infected with a partially drug-resistant strain. This study reports the efficacy of LYC-PLA-PEG-NC at higher doses in mice infected with a T. cruzi strain resistant to benznidazole (BZ) and nifurtimox (NF) treated at both the acute phase (AP) and the chronic phase (CP) of infection by the oral route. Mice infected with the T. cruzi VL-10 strain were treated by the oral route with free LYC (12 mg/kg of body weight/day), LYC-PLA-PEG-NC (8 or 12 mg/kg/day), or BZ at 100 mg/kg/day or were not treated (controls). Treatment efficacy was assessed by hemoculture (HC), PCR, enzyme-linked immunosorbent assay (ELISA), heart tissue quantitative PCR (qPCR), and histopathology. According to classical cure criteria, treatment with LYC-PLA-PEG-NC at 12 mg/kg/day cured 75% (AP) and 88% (CP) of the animals, while at a dose of 8 mg/kg/day, 43% (AP) and 43% (CP) were cured, showing dose-dependent efficacy. The negative qPCR results for heart tissue and the absence of inflammation/fibrosis agreed with the negative results obtained by HC and PCR. Thus, the mice treated with the highest dose could be considered 100% cured, in spite of a low ELISA reactivity in some animals. No cure was observed in animals treated with free LYC or BZ or the controls. These results are exceptional in terms of experimental Chagas disease chemotherapy and provide evidence of the outstanding contribution of nanotechnology in mice infected with a T. cruzi strain totally resistant to BZ and NF at both phases of infection. Therefore, LYC-PLA-PEG-NC has great potential as a new treatment for Chagas disease and deserves further investigations in clinical trials.
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    Lychnopholide in Poly(D,L-Lactide)-block-polyethylene glycol nanocapsules cures infection with a drug-resistant Trypanosoma cruzi strain at acute and chronic phases.
    (2020) Branquinho, Renata Tupinambá; Mello, Carlos Geraldo Campos de; Oliveira, Maykon Tavares de; Reis, Levi Eduardo Soares; Vieira, Paula Melo de Abreu; Guimarães, Dênia Antunes Saúde; Mosqueira, Vanessa Carla Furtado; Lana, Marta de
    Chagas disease remains neglected, and current chemotherapeutics present severe limitations. Lychnopholide (LYC) at low doses loaded in polymeric poly(D,L-lactide)-block-polyethylene glycol (PLA-PEG) nanocapsules (LYC-PLA-PEG-NC) exhibits anti-Trypanosoma cruzi efficacy in mice infected with a partially drugresistant strain. This study reports the efficacy of LYC-PLA-PEG-NC at higher doses in mice infected with a T. cruzi strain resistant to benznidazole (BZ) and nifurtimox (NF) treated at both the acute phase (AP) and the chronic phase (CP) of infection by the oral route. Mice infected with the T. cruzi VL-10 strain were treated by the oral route with free LYC (12 mg/kg of body weight/day), LYC-PLA-PEG-NC (8 or 12 mg/kg/day), or BZ at 100 mg/kg/day or were not treated (controls). Treatment efficacy was assessed by hemoculture (HC), PCR, enzyme-linked immunosorbent assay (ELISA), heart tissue quantitative PCR (qPCR), and histopathology. According to classical cure criteria, treatment with LYC-PLA-PEG-NC at 12 mg/kg/day cured 75% (AP) and 88% (CP) of the animals, while at a dose of 8 mg/kg/day, 43% (AP) and 43% (CP) were cured, showing dose-dependent efficacy. The negative qPCR results for heart tissue and the absence of inflammation/fibrosis agreed with the negative results obtained by HC and PCR. Thus, the mice treated with the highest dose could be considered 100% cured, in spite of a low ELISA reactivity in some animals. No cure was observed in animals treated with free LYC or BZ or the controls. These results are exceptional in terms of experimental Chagas disease chemotherapy and provide evidence of the outstanding contribution of nanotechnology in mice infected with a T. cruzi strain totally resistant to BZ and NF at both phases of infection. Therefore, LYC-PLA-PEG-NC has great potential as a new treatment for Chagas disease and deserves further investigations in clinical trials.
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    Medicamentos anti-hipertensivos utilizados na área rural de Ouro Preto, MG.
    (2007) Silva, Adriana Carneiro; Pereira, Roberta Verciano; Figueiredo, Bárbara de Castro Pimentel; Couto, Wagner Faria; Gramigna, Luísa Leite; Sana, Dandara Emery Morais; Gomes, Rodrigo Saar; Andrade, Graziela de Fátima; Brant, João Francisco de Avelar Caldeira; Breguez, Gustavo Silveira; Silva, Mariana Augusta Resende; Barbeitos, Priscila Oliveira; Junior, Luiz Carlos Pereira; Reis, Levi Eduardo Soares; Jayme, Marisa Ferrareto; Camargo, Rúbia Santos; Franco, Marcelo Nóbile; Amaral, Murilo Sena; Carneiro, Cláudia Martins; Guimarães, Andrea Grabe
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    Mixed formulation of conventional and pegylated meglumine antimoniate-containing liposomes reduces inflammatory process and parasite burden in Leishmania infantum-infected BALB/c mice.
    (2017) Reis, Levi Eduardo Soares; Brito, Rory Cristiane Fortes de; Cardoso, Jamille Mirelle de Oliveira; Mathias, Fernando Augusto Siqueira; Soares, Rodrigo Dian de Oliveira Aguiar; Carneiro, Cláudia Martins; Vieira, Paula Melo de Abreu; Ramos, Guilherme Santos; Frezard, Frederic Jean Georges; Roatt, Bruno Mendes; Reis, Alexandre Barbosa
    Pentavalent antimonial has been the first choice treatment for visceral leishmaniasis; however, it has several side effects that leads to low adherence to treatment. Liposome-encapsulated meglumine antimoniate (MA) arises as an important strategy for chemotherapy enhancement. We evaluated the immunopathological changes using the mixture of conventional and pegylated liposomes with MA. The mice were infected with Leishmania infantum and a single-dose treatment regimen. Comparison was made with groups treated with saline, empty liposomes, free MA, and a liposomal formulation of MA (Lipo MA). Histopathological analyses demonstrated that animals treated with Lipo MA showed a significant decrease in the inflammatory process and the absence of granulomas. The in vitro stimulation of splenocytes showed a significant increase of gamma interferon (IFN-γ) produced by CD8+ T cells and a decrease in interleukin-10 (IL-10) produced by CD4+ and CD8+ T cells in the Lipo MA. Furthermore, the Lipo MA group showed an increase in the IFN-γ/IL-10 ratio in both CD4+ and CD8+ T cell subsets. According to the parasite load evaluation using quantitative PCR, the Lipo MA group showed no L. infantum DNA in the spleen (0.0%) and 41.4% in the liver. In addition, we detected a low positive correlation between parasitism and histopathology findings (inflammatory process and granuloma formation). Thus, our results confirmed that Lipo MA is a promising antileishmanial formulation able to reduce the inflammatory response and induce a type 1 immune response, accompanied by a significant reduction of the parasite burden into hepatic and splenic compartments in treated animals.