Navegando por Autor "Martins, Vívian Tamietti"
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Item Acarbose presents in vitro and in vivo antileishmanial activity against Leishmania infantum and is a promising therapeutic candidate against visceral leishmaniasis.(2020) Costa, Rafaella Rodrigues; Silva, João Augusto Oliveira da; Reis, Thiago Alves Rosa dos; Tavares, Grasiele de Sousa Vieira; Mendonça, Débora Vasconcelos Costa; Freitas, Camila Simões de; Lage, Daniela Pagliara; Martins, Vívian Tamietti; Antinarelli, Luciana Maria Ribeiro; Machado, Amanda Sanchez; Bandeira, Raquel Soares; Ribeiro, Fernanda Ludolf; Santos, Thaís Teodoro de Oliveira; Brito, Rory Cristiane Fortes de; Humbert, Maria Victoria; Souza, Daniel Menezes; Duarte, Mariana Costa; Chávez Fumagalli, Miguel Angel; Roatt, Bruno Mendes; Coimbra, Elaine Soares; Coelho, Eduardo Antônio FerrazTreatment against visceral leishmaniasis (VL) is mainly hampered by drug toxicity, long treatment regimens and/or high costs. Thus, the identifcation of novel and low-cost antileishmanial agents is urgent. Acarbose (ACA) is a specifc inhibitor of glucosidase-like proteins, which has been used for treating diabetes. In the present study, we show that this molecule also presents in vitro and in vivo specifc antileishmanial activity against Leishmania infantum. Results showed an in vitro direct action against L. infantum promastigotes and amastigotes, and low toxicity to mammalian cells. In addition, in vivo experiments performed using free ACA or incorporated in a Pluronic® F127-based polymeric micelle system called ACA/ Mic proved efective for the treatment of L. infantum-infected BALB/c mice. Treated animals presented signifcant reductions in the parasite load in their spleens, livers, bone marrows and draining lymph nodes when compared to the controls, as well as the development of antileishmanial Th1-type humoral and cellular responses based on high levels of IFN-γ, IL-12, TNF-α, GM-CSF, nitrite and IgG2a isotype antibodies. In addition, ACA or ACA-treated animals sufered from low organ toxicity. Treatment with ACA/Mic outperformed treatments using either Miltefosine or free ACA based on parasitological and immunological evaluations performed one and 15 days post-therapy. In conclusion, data suggest that the ACA/Mic is a potential therapeutic agent against L. infantum and merits further consideration for VL treatment.Item Digitoxigenin presents an effective and selective antileishmanial action against Leishmania infantum and is a potential therapeutic agent for visceral leishmaniasis.(2020) Freitas, Camila Simões de; Silva, João Augusto Oliveira da; Lage, Daniela Pagliara; Costa, Rafaella Rodrigues; Mendonça, Débora Vasconcelos Costa; Martins, Vívian Tamietti; Reis, Thiago Alves Rosa dos; Antinarelli, Luciana Maria Ribeiro; Machado, Amanda Sanchez; Tavares, Grasiele de Sousa Vieira; Ramos, Fernanda Fonseca; Coelho, Vinicio Tadeu da Silva; Brito, Rory Cristiane Fortes de; Ribeiro, Fernanda Ludolf; Chávez Fumagalli, Miguel Angel; Roatt, Bruno Mendes; Ramos, Gabriela S.; Munkert, Jennifer; Ottoni, Flaviano Melo; Campana, Priscilla Rodrigues Valadares; Humbert, Maria Victoria; Coimbra, Elaine Soares; Braga, Fernão Castro; Pádua, Rodrigo Maia de; Coelho, Eduardo Antônio FerrazTreatment for visceral leishmaniasis (VL) is hampered mainly by drug toxicity, their high cost, and parasite resistance. Drug development is a long and pricey process, and therefore, drug repositioning may be an alternative worth pursuing. Cardenolides are used to treat cardiac diseases, especially those obtained from Digitalis species. In the present study, cardenolide digitoxigenin (DIGI) obtained from a methanolic extract of Digitalis lanata leaves was tested for its antileishmanial activity against Leishmania infantum species. Results showed that 50% Leishmania and murine macrophage inhibitory concentrations (IC50 and CC50, respectively) were of 6.9 ± 1.5 and 295.3 ± 14.5 μg/mL, respectively. With amphotericin B (AmpB) deoxycholate, used as a control drug, values of 0.13 ± 0.02 and 0.79 ± 0.12 μg/mL, respectively, were observed. Selectivity index (SI) values were of 42.8 and 6.1 for DIGI and AmpB, respectively. Preliminary studies suggested that the mechanism of action for DIGI is to cause alterations in the mitochondrial membrane potential, to increase the levels of reactive oxygen species and induce accumulation of lipid bodies in the parasites. DIGI was incorporated into Pluronic® F127-based polymeric micelles, and the formula (DIGI/Mic) was used to treat L. infantum–infected mice. Miltefosine was used as a control drug. Results showed that animals treated with either miltefosine, DIGI, or DIGI/Mic presented significant reductions in the parasite load in their spleens, livers, bone marrows, and draining lymph nodes, as well as the development of a specific Th1-type response, when compared with the controls. Results obtained 1 day after treatment were corroborated with data corresponding to 15 days after therapy. Importantly, treatment with DIGI/Mic induced better parasitological and immunological responses when compared with miltefosine- and DIGI-treated mice. In conclusion, DIGI/Mic has the potential to be used as a therapeutic agent to protect against L. infantum infection, and it is therefore worth of consideration in future studies addressing VL treatment.Item Exploring drug repositioning for leishmaniasis treatment : ivermectin plus polymeric micelles induce immunological response and protection against tegumentary leishmaniasis.(2023) Freitas, Camila Simões de; Lage, Daniela Pagliara; Machado, Amanda Sanchez; Vale, Danniele Luciana; Martins, Vívian Tamietti; Cardoso, Jamille Mirelle de Oliveira; Silva, João Augusto Oliveira da; Reis, Thiago Alves Rosa dos; Tavares, Grasiele de Sousa Vieira; Ramos, Fernanda Fonseca; Ribeiro, Fernanda Ludolf; Pereira, Isabela Amorim Gonçalves; Bandeira, Raquel Soares; Fujiwara, Ricardo Toshio; Bueno, Lilian Lacerda; Roatt, Bruno Mendes; Chávez Fumagalli, Miguel Angel; Coelho, Eduardo Antônio FerrazLeishmania amazonensis can cause a wide spectrum of the clinical manifestations of leishmaniasis in humans. The development of new therapeutics is a long and expensive task; in this context, drug repositioning could be considered a strategy to identify new biological actions of known products. In the present study, ivermectin (IVE) was tested against distinct Leishmania species able to cause disease in humans. In vitro experiments showed that IVE was effective to reduce the infection degree and parasite load in Leishmania donovani- and L. amazonensisinfected macrophages that were treated with it. In addition, using the culture supernatant of treated macrophages, higher production of IFN-γ and IL-12 and lower levels of IL-4 and IL-10 were found. Then, IVE was used in a pure form or incorporated into Poloxamer 407-based polymeric micelles (IVE/M) for the treatment of L. amazonensis-infected BALB/c mice. Animals (n = 16 per group) were infected and later received saline, empty micelles, amphotericin B (AmpB), IVE, or IVE/M. They were euthanized at one (n = 8 per group) and 30 (n = 8 per group) days after treatment and, in both endpoints, immunological, parasitological, and biochemical evaluations were performed. Results showed that both IVE and IVE/M induced higher levels of IFN-γ, IL-12, GM-CSF, nitrite, and IgG2a antibodies, as well as higher IFN-γ expression evaluated by RT-qPCR in spleen cell cultures. Such animals showed low organic toxicity, as well as significant reductions in the lesion’s average diameter and parasite load in their infected tissue, spleen, liver, and draining lymph node. The efficacy was maintained 30 days post-therapy, while control mice developed a polarized Th2-type response and high parasite load. In this context, IVE could be considered as a new candidate to be applied in future studies for the treatment against distinct Leishmania species.Item In vitro and in vivo antileishmanial activity of b-acetyl-digitoxin, a cardenolide of Digitalis lanata potentially useful to treat visceral leishmaniasis.(2021) Freitas, Camila Simões de; Lage, Daniela Pagliara; Silva, João Augusto Oliveira da; Costa, Rafaella Rodrigues; Mendonça, Débora Vasconcelos Costa; Martins, Vívian Tamietti; Reis, Thiago Alves Rosa dos; Antinarelli, Luciana Maria Ribeiro; Machado, Amanda Sanchez; Tavares, Grasiele de Sousa Vieira; Ramos, Fernanda Fonseca; Brito, Rory Cristiane Fortes de; Ribeiro, Fernanda Ludolf; Chávez Fumagalli, Miguel Angel; Roatt, Bruno Mendes; Ramos, Gabriela S.; Munkert, Jennifer; Ottoni, Flaviano Melo; Campana, Priscilla Rodrigues Valadares; Duarte, Mariana Costa; Gonçalves, Denise Utsch; Coimbra, Elaine Soares; Braga, Fernão Castro; Pádua, Rodrigo Maia de; Coelho, Eduardo Antônio FerrazCurrent treatments of visceral leishmaniasis face limitations due to drug side effects and/or high cost, along with the emergence of parasite resistance. Novel and low-cost antileishmanial agents are therefore required. We report herein the antileishmanial activity of b-acetyl-digitoxin (b-AD), a cardenolide isolated from Digitalis lanata leaves, assayed in vitro and in vivo against Leishmania infantum. Results showed direct action of b-AD against parasites, as well as efficacy for the treatment of Leishmania-infected macrophages. In vivo experiments using b-AD-containing Pluronic F127 polymeric micelles (b-AD/Mic) to treat L. infantum-infected mice showed that this composition reduced the parasite load in distinct organs in more significant levels. It also induced the development of anti-parasite Th1-type immunity, attested by high levels of IFN-c, IL-12, TNF-a, GM-CSF, nitrite and specific IgG2a antibodies, in addition to low IL-4 and IL-10 contents, along with higher IFN-c-producing CD4+ and CD8+ T-cell frequency. Furthermore, low toxicity was found in the organs of the treated animals. Comparing the therapeutic effect between the treatments, b-AD/Mic was the most effective in protecting animals against infection, when compared to the other groups including miltefosine used as a drug control. Data found 15 days after treatment were similar to those obtained one day post-therapy. In conclusion, the results obtained suggest that b-AD/Mic is a promising antileishmanial agent and deserves further studies to investigate its potential to treat visceral leishmaniasis.Item Ivermectin presents effective and selective antileishmanial activity in vitro and in vivo against Leishmania infantum and is therapeutic against visceral leishmaniasis.(2021) Reis, Thiago Alves Rosa dos; Silva, João Augusto Oliveira da; Tavares, Grasiele de Sousa Vieira; Mendonça, Débora Vasconcelos Costa; Freitas, Camila Simões de; Costa, Rafaella Rodrigues; Lage, Daniela Pagliara; Martins, Vívian Tamietti; Machado, Amanda Sanchez; Ramos, Fernanda Fonseca; Silva, Alessandra M.; Ribeiro, Fernanda Ludolf; Antinarelli, Luciana Maria Ribeiro; Brito, Rory Cristiane Fortes de; Chávez Fumagalli, Miguel Angel; Humbert, Maria Victoria; Roatt, Bruno Mendes; Coimbra, Elaine Soares; Coelho, Eduardo Antônio FerrazTreatment for visceral leishmaniasis (VL) is hindered mainly by the toxicity and/or high cost of therapeutic drugs. In addition, parasite resistance has been registered. Thus, there is an urgent need for the identification of novel, effective and low-cost antileishmanial agents. Since drug discovery is a long and expensive process, drug repositioning for treatment of leishmaniasis should be considered. In the present study, Ivermectin (IVE), a broad-spectrum drug used for treatment of parasitic diseases, was evaluated in vitro and in vivo against Leishmania infantum species. Results in vitro showed that IVE presented 50% Leishmania and macrophage inhibitory concentrations (IC50 and CC50, respectively) of 3.64 ± 0.48 μM and 427.50 ± 17.60 μM, respectively, with a selectivity index (SI) of 117.45; whereas Amphotericin B (AmpB), which was used as control, showed IC50 and CC50 values of 0.12 ± 0.05 μM and 1.06 ± 0.23 μM, respectively, with a corresponding SI of 8.90. Treatment with IVE effectively reduced the infection percentage and parasite burden in infected and treated macrophages and displayed a prophylactic activity by inhibiting macrophage infection with pre-treated parasites. Furthermore, preliminary studies suggested that IVE targets the parasite’s mitochondria. Activity of IVE in its free format or incorporated into Pluronic® F127-based polymeric micelles (IVE/Mic) was also evaluated in vivo as a treating drug for L. infantum-infected BALB/c mice. Miltefosine was used as a control. Results showed that Miltefosine, IVE and IVE/Mic-treated animals presented significant reductions in the parasite load in their spleens, livers, bone marrows and draining lymph nodes, as well as development of an antileishmanial Th1-type immune response one and 15 days after treatment. Notably, IVE/Mic showed a better parasitological and immunological response in comparison to other alternative treatments. In conclusion, results suggest that IVE/Mic could be considered in future studies as a therapeutic alternative to treat VL.Item Leishmania eukaryotic elongation Factor-1 beta protein is immunogenic and induces parasitological protection in mice against Leishmania infantum infection.(2021) Santos, Thaís Teodoro de Oliveira; Machado, Amanda Sanchez; Ramos, Fernanda Fonseca; Silva, João Augusto Oliveira da; Lage, Daniela Pagliara; Tavares, Grasiele de Sousa Vieira; Mendonça, Débora Vasconcelos Costa; Cardoso, Mariana Santos; Siqueira, Williane Fernanda; Martins, Vívian Tamietti; Ribeiro, Fernanda Ludolf; Reis, Thiago Alves Rosa dos; Carvalho, Lívia Mendes; Freitas, Camila Simões de; Bandeira, Raquel Soares; Silva, Alessandra M.; Oliveira, Jamil Silvano de; Moreira, Ricardo Luiz Fontes; Fujiwara, Ricardo Toshio; Roatt, Bruno Mendes; Chávez Fumagalli, Miguel Angel; Humbert, Maria Victoria; Teixeira, Antônio Lúcio; Coelho, Eduardo Antônio FerrazTreatment for visceral leishmaniasis (VL) is hampered mainly by the toxicity and/or high cost of antileishmanial drugs. What is more, variability on sensitivity and/or specificity of diagnostic tests hinders effective disease management. In this context, prophylactic vaccination should be considered as a strategy to prevent disease. In the present study, immunogenicity of the Leishmania eukaryotic Elongation Factor-1 beta (EF1b) protein, classified as a Leishmania virulence factor, was evaluated in vitro and in vivo and tested, for the first time, as a vaccine candidate against Leishmania infantum infection. The antigen was administered as DNA vaccine or as recombinant protein (rEF1b) delivered in saponin. BALB/c mice immunization with a DNA plasmid and recombinant protein plus saponin induced development of specific Th1-type immunity, characterized by high levels of IFN-γ, IL-12, GM-CSF, both T cell subtypes and antileishmanial IgG2a isotype antibodies, before and after infection. This immunological response to the vaccines was corroborated further by parasitological analysis of the vaccinated and then challenged mice, which showed significant reductions in the parasite load in their liver, spleen, bone marrow and draining lymph nodes, when compared to the controls. Vaccination using rEF1b/saponin induced a more robust Th1 response and parasitological protection when compared to the DNA vaccine. Furthermore, in vitro analysis of lymphoproliferation, IFN-γ and IL-10 levels in human PBMC cultures showed as well development of a specific Th1-type response. In conclusion, data suggest that EF1b could be a promising vaccine candidate to protect against L. infantum infection.Item Leishmania infantum pyridoxal kinase evaluated in a recombinant protein and DNA vaccine to protects against visceral leishmaniasis.(2020) Silva, João Augusto Oliveira da; Lage, Daniela Pagliara; Ramos, Fernanda Fonseca; Machado, Amanda Sanchez; Tavares, Grasiele de Sousa Vieira; Mendonça, Débora Vasconcelos Costa; Pereira, Isabela Amorim Gonçalves; Martins, Vívian Tamietti; Carvalho, Lívia Mendes; Ribeiro, Fernanda Ludolf; Santos, Thaís Teodoro de Oliveira; Reis, Thiago Alves Rosa dos; Oliveira, Camila S.; Bandeira, Raquel Soares; Silva, Alessandra M.; Costa, Lourena Emanuele; Oliveira, Jamil Silvano de; Duarte, Mariana Costa; Souza, Daniel Menezes; Roatt, Bruno Mendes; Teixeira, Antonio Lucio; Coelho, Eduardo Antônio FerrazLeishmania infantum pyridoxal kinase (PK) protein was characterized after an immunoproteomics screening performed with the sera from patients suffering visceral leishmaniasis (VL). Since it was recognized by sera of mammalian hosts infected by a viscerotropic Leishmania species, PK could emerge as a new vaccine candidate against disease, due to its antigenicity and immunogenicity. In this context, in the present study, the effects of the immunization using PK were evaluated when administered as a DNA plasmid (pDNAA3/PK) or recombinant protein (rPK) plus saponin. The immune response elicited by both vaccination regimens reduced in significant levels the parasite load in spleen, liver, draining lymph nodes and bone marrow, being associated with the development of Th1-type immune response, which was characterized by high levels of IFN-γ, IL-12, GM-CSF, and specific IgG2a antibody, besides low production of IL-4, IL-10, and protein and parasite-specific IgG1 antibodies. CD8+ T cells were more important in the IFN-γ production in the pDNAA3/PK group, while CD4+ T cells contributed more significantly to production of this cytokine in the rPK/Saponin group. In addition, increased IFN-γ secretion, along with low levels of IL-10, were found when PBMCs from VL patients after treatment and healthy individuals were stimulated with the protein. In conclusion, when administered either as a DNA plasmid or recombinant protein plus adjuvant, PK can direct the immune response towards a Th1-type immune profile, protecting mice against L. infantum challenge; therefore, it can be seen as a promising immunogen against human VL.Item Recombinant endonuclease III protein from Leishmania infantum associated with Th1-type adjuvants is immunogenic and induces protection against visceral leishmaniasis.(2023) Lage, Daniela Pagliara; Machado, Amanda Sanchez; Freitas, Camila Simões de; Vale, Danniele Luciana; Linhares, Flávia Prata; Cardoso, Jamille Mirelle de Oliveira; Silva, João Augusto Oliveira da; Ramos, Fernanda Fonseca; Pereira, Isabela Amorim Gonçalves; Ribeiro, Fernanda Ludolf; Tavares, Grasiele de Sousa Vieira; Bandeira, Raquel Soares; Oliveira, Jamil Silvano de; Souza, Daniel Menezes; Duarte, Mariana Costa; Galdino, Alexsandro Sobreira; Christodoulides, Myron; Chávez Fumagalli, Miguel Angel; Roatt, Bruno Mendes; Martins, Vívian Tamietti; Coelho, Eduardo Antônio FerrazVaccination against visceral leishmaniasis (VL) should be considered as a safe and effective measure to disease control; however, few vaccines are available against canine VL and there is no an approved human vaccine. In this context, in the present study, we evaluated the endonuclease III (ENDO) protein, which was recently showed to be antigenic for human disease, as a vaccine candidate against Leishmania infantum infection. The recombinant protein (rENDO) was administered in BALB/c mice alone or associated with saponin (rENDO/Sap) or micelles (rENDO/Mic) as adjuvants. Controls received saline, saponin or empty micelles. Results showed that both rENDO/Sap and rENDO/Mic compositions induced higher levels of IFN-γ, IL-12, TNF-α, and GM-CSF cytokines, besides nitrite and IgG2a isotype antibodies, before and after challenge infection, which were related to both CD4+ and CD8+ T cell subtypes. The immunological results contributed to significant reductions in the parasite load found in the spleens, livers, bone marrows and draining lymph nodes of the vaccinated animals. In general, mice immunized with rENDO/Mic presented a slightly higher Th1-type cellular and humoral immune response, as compared to those receiving rENDO/Sap. In addition, saponin caused a slight to moderate inflammatory edema in their vaccinated footpads, which was not observed when micelles were used with rENDO. In addition, a preliminary analysis showed that the recombinant protein was immunogenic to human cells cultures, since PBMCs from treated VL patients and healthy subjects showed higher lymphoproliferation and IFN-γ production in the culture supernatants. In conclusion, data suggest that rENDO could be considered as a candidate to be evaluated in future studies as vaccine to protect against VL.Item Sensitive and specific serodiagnosis of Leishmania infantum infection in dogs using peptides selected from hypothetical proteins identified by an immunoproteomic approach.(2013) Chávez Fumagalli, Miguel Angel; Martins, Vívian Tamietti; Testasicca, Miriam Conceição de Souza; Lage, Daniela Pagliara; Costa, Lourena Emanuele; Lage, Paula Souza; Duarte, Mariana Costa; Ker, Henrique Gama; Ribeiro, Tatiana Gomes; Carvalho, Fernando Aécio de Amorim; Régis, Wiliam César Bento; Reis, Alexandre Barbosa; Tavares, Carlos Alberto Pereira; Soto, Manuel; Fernandes, Ana Paula Salles Moura; Coelho, Eduardo Antônio FerrazIn Brazil, the percentage of infected dogs living in areas where canine visceral leishmaniasis (CVL) is endemic ranges from 10 to 62%; however, the prevalence of infection in dogs is probably higher than figures reported from serological studies. In addition, problems with the occurrence of false-positive or false-negative results in the serodiagnosis of CVL have been reported. The present work analyzed the potential of synthetic peptides mapped from hypothetical proteins for improvement of the serodiagnosis of Leishmania infantum infection in dogs. From 26 identified leishmanial proteins, eight were selected, considering that no homologies between these proteins and others from trypanosomatide sequence databases were encountered. The sequences of these proteins were mapped to identify linear B-cell epitopes, and 17 peptides were synthesized and tested in enzyme-linked immunosorbent assays (ELISAs) for the serodiagnosis of L. infantum infection in dogs. Of these, three exhibited sensitivity and specificity values higher than 75% and 90%, respectively, to differentiate L. infantum-infected animals from Trypanosoma cruziinfected animals and healthy animals. Soluble Leishmania antigen (SLA) showed poor sensitivity (4%) and specificity (36%) to differentiate L. infantum-infected dogs from healthy and T. cruzi-infected dogs. Lastly, the three selected peptides were combined in different mixtures and higher sensitivity and specificity values were obtained, even when sera from T. cruzi-infected dogs were used. The study’s findings suggest that these three peptides can constitute a potential tool for more sensitive and specific serodiagnosis of L. infantum infection in dogs.