Navegando por Autor "Tavares, Carlos Alberto Pereira"
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Item An 8-hydroxyquinoline-containing polymeric micelle system is effective for the treatment of murine tegumentary leishmaniasis.(2016) Lage, Letícia Martins dos Reis; Barichello, José Mario; Lage, Daniela Pagliara; Mendonça, Débora Vasconcelos Costa; Carvalho, Ana Maria Ravena Severino; Rodrigues, Marcella Rezende; Souza, Daniel Menezes; Roatt, Bruno Mendes; Alves, Ricardo José; Tavares, Carlos Alberto Pereira; Coelho, Eduardo Antônio Ferraz; Duarte, Mariana CostaItem Comparative evaluation of phenol and thimerosal as preservatives for a candidate vaccine against American cutaneous leishmaniasis.(2010) Mayrink, Wilson; Tavares, Carlos Alberto Pereira; Deus, Rosângela Barbosa de; Pinheiro, Melina Barros; Guimarães, Tânia Mara Pinto Dabés; Andrade, Hélida Monteiro de; Costa, Carlos Alberto da; Toledo, Vicente de Paulo Coelho Peixoto deFor decades thimerosal has been used as a preservative in the candidate vaccine for cutaneous leishmaniasis, which was developed by Mayrink et al. The use of thimerosal in humans has been banned due to its mercury content. This study addresses the standardization of phenol as a new candidate vaccine preservative. We have found that the proteolytic activity was abolished when the test was conducted using the candidate vaccine added to merthiolate (MtVac) as well as to phenol (PhVac). The Montenegro’s skin test conversion rates induced by MtVac and by PhVac was 68.06% and 85.9%, respectively, and these values were statistically significant (p < 0.05). The proliferative response of peripheral mononuclear blood cells shows that the stimulation index of mice immunized with both candidate vaccines was higher than the one in control animals (p < 0.05). The ability of the candidate vaccines to induce protection in C57BL/10 mice against a challenge with infective Leishmania amazonensis promastigotes was tested and the mice immunized with PhVac developed smaller lesions than the mice immunized with MtVac. Electrophoresis of phenol-preserved antigen revealed a number of proteins, which were better preserved in PhVac. These results do in fact encourage the use of phenol for preserving the immunogenic and biochemical properties of the candidate vaccine for cutaneous leishmaniasis.Item Comparing the therapeutic efficacy of different amphotericin Bcarrying delivery systems against visceral leishmaniasis.(2018) Mendonça, Débora Vasconcelos Costa; Martins, Vivian Tamietti; Lage, Daniela Pagliara; Ribeiro, Patrícia Aparecida Fernandes; Carvalho, Ana Maria Ravena Severino; Dias, Anna Leticia Teotonio; Miyazaki, Carolina Kei; Souza, Daniel Menezes; Roatt, Bruno Mendes; Tavares, Carlos Alberto Pereira; Duarte, Mariana Costa; Coelho, Eduardo Antônio FerrazAmphotericin B (Amp) has been well-successfully used to treat against Leishmania infection, although high toxicity has been found in patients. In the present study, Amp was administered in Leishmania infantum-infected BALB/c mice by three distinct delivery systems aiming to compare their efficacy against challenge infection, as well as their side effects in a murine visceral leishmaniasis (VL) model. This product was administered in a Poloxamer P407 (Pluronic® F127)-based polymeric micelle system (Amp/M), in the Ambisome® formulation (Lip-Amp) or in a free format (free Amp). Glucantime® (Gluc) was used as a comparative drug. Aiming to evaluate different endpoints of the treatments, the efficacy of the compounds was investigated one and 15-days after the therapeutic regimens, determining the parasite load by a limiting dilution assay and a quantitative PCR (qPCR) technique, as well as evaluating the immune response generated in the infected and treated animals. In the results, Amp/M or Lip-Amp-treated mice presented the best outcomes, since significant parasite load reductions were found in the evaluated organs, as well as a parasite-specific Th1 immune response was observed in the animals. In addition, no hepatic or renal damage was found in these mice. On the other hand, free Amp or Gluc induced toxicity in the animals, which was associated with a low Th1 immune response. Comparatively, Amp/M was the most effective drug in our experimental model, and results showed that the Amp-carrying system could be considered as a future alternative in studies against VL.Item Evaluation of immune responses and protection induced by A2 and nucleoside hydrolase (NH) DNA vaccines against Leishmania chagasi and Leishmania amazonensis experimental infections.(2007) Zanin, Francisca Helena Calheiros; Coelho, Eduardo Antônio Ferraz; Tavares, Carlos Alberto Pereira; Silva, Eduardo de Almeida Marques da; Costa, Miriam Maria Silva; Rezende, Simone Aparecida; Gazzinelli, Ricardo Tostes; Fernandes, Ana Paula Salles MouraSeveral antigens have been tested as vaccine candidates against Leishmania infections but controversial results have been reported when different antigens are co-administered in combined vaccination protocols. Immunization with A2 or nucleoside hydrolase (NH) antigens was previously shown to induce Th1 immune responses and protection in BALB/c mice against Leishmania donovani and L. amazonensis (A2) or L. donovani and L. mexicana (NH) infections. In this work, we investigated the protective efficacy of A2 and NH DNA vaccines, in BALB/c mice, against L. amazonensis or L. chagasi challenge infection. Immunization with either A2 (A2-pCDNA3) or NH (NH-VR1012) DNA induced an elevated IFN-g production before infection; however, only A2 DNA immunized mice were protected against both Leishmania species and displayed a sustained IFN-g production and very low IL-4 and IL-10 levels, after challenge. Mice immunized with NH/A2 DNA produced higher levels of IFN-g in response to both specific recombinant proteins (rNH or rA2), but displayed higher IL-4 and IL-10 levels and increased edema and parasite loads after L. amazonensis infection, as compared to A2 DNA immunized animals. These data extend the characterization of the immune responses induced by NH and A2 antigens as potential candidates to compose a defined vaccine and indicate that a highly polarized type 1 immune response is required for improvement of protective levels of combined vaccines against both L. amazonensis and L. chagasi infections.Item Intramuscular immunization with p36(LACK) DNA vaccine induces IFN-gama production but does not protect BALB/c mice against Leishmania chagasi intravenous challenge.(2005) Silva, Eduardo de Almeida Marques da; Coelho, Eduardo Antônio Ferraz; Gomes, Daniel Cláudio de Oliveira; Vilela, Márcia de Carvalho; Masioli, Cássio Zumerle; Tavares, Carlos Alberto Pereira; Fernandes, Ana Paula Salles Moura; Afonso, Luís Carlos Crocco; Rezende, Simone AparecidaAcute visceral leishmaniasis is a progressive disease caused by Leishmania chagasi in South America. The acquisition of immunity following infection suggests that vaccination is a feasible approach to protect against this disease. Since Leishmania homologue of receptors for activated C kinase (LACK) antigen is of particular interest as a vaccine candidate because of the prominent role it plays in the pathogenesis of experimental Leishmania major infection, we evaluated the potential of a p36(LACK) DNA vaccine in protecting BALB/c mice challenged with L. chagasi. In this study, mice received intramuscular (i.m.) or subcutaneous (s.c.) doses of LACK DNA vaccine. We evaluated the production of vaccine-induced cytokines and whether this immunization was able to reduce parasite load in liver and spleen. We detected a significant production of interferon gamma by splenocytes from i.m. vaccinated mice in response to L. chagasi antigen and to rLACK protein. However, we did not observe a reduction in parasite load neither in liver nor in the spleen of vaccinated animals. The lack of protection observed may be explained by a significant production of IL-10 induced by the vaccine.Item A Leishmania hypothetical protein-containing liposome-based formulation is highly immunogenic and induces protection against visceral leishmaniasis.(2018) Ribeiro, Patrícia Aparecida Fernandes; Dias, Daniel Silva; Novais, Marcus V. M.; Lage, Daniela Pagliara; Tavares, Grasiele de Sousa Vieira; Mendonça, Débora Vasconcelos Costa; Oliveira, Jamil Silvano de; Chávez Fumagalli, Miguel Angel; Roatt, Bruno Mendes; Duarte, Mariana Costa; Souza, Daniel Menezes; Ribeiro, Fernanda Ludolf; Tavares, Carlos Alberto Pereira; Oliveira, Mônica Cristina de; Coelho, Eduardo Antônio FerrazLeishmania proteins have been evaluated as vaccine candidates against leishmaniasis; however, most antigens present low immunogenicity and need to be added with immune adjuvants. A low number of licensed adjuvants exist on the market today; therefore, research conducted to produce new products is desirable. The present study sought to evaluate the immunogenicity and protective efficacy of a recombinant Leishmania hypothetical protein, namely LiHyR, administered with saponin or liposomes in BALB/c mice. Immunological and parasitological parameters were evaluated, and results showed significant protection against Leishmania infantum infection produced by both compositions in the immunized animals; however, this was not identified when the antigen was used alone. In addition, the liposomal formulation was more effective in inducing a polarized Th1 response in the vaccinated animals, which was maintained after challenge and reflected by lower parasitism found in all evaluated organs when the limiting dilution technique and RT-PCR assay were employed. The protected animals showed higher levels of protein and parasite-specific IFN-γ IL-2, IL-12, GM-CSF, and TNF-α, which were evaluated by capture ELISA and flow cytometry, in addition to a higher production of anti-protein and anti-parasite IgG2a antibodies, both before and after challenge. The Lip/rLiHyR combination induced higher IFN-γ production through both CD4+ and CD8+ T cell subtypes. Results indicate the possibility of using the LiHyR, containing a liposomal formulation, as a vaccine candidate against visceral leishmaniasis.Item Leishmania major-like antigen for specific and sensitive serodiagnosis of human and canine visceral leishmaniasis.(2002) Deus, Rosângela Barbosa de; Guia, Marcos Luíz dos Mares; Nunes, Adriane Zacarias; Costa, Kátia Morais; Junqueira, Roberto Gonçalves; Mayrink, Wilson; Genaro, Odair; Tavares, Carlos Alberto PereiraAn antigen (LMS) prepared from Leishmania major-like promastigotes was used in an enzyme-linked immunosorbent assay (ELISA) for the diagnosis of human and dog visceral leishmaniasis. The results were compared with those from the indirect immunofluorescent antibody test (IFAT). A total of 1,822 canine sera were tested, including sera from dogs with visceral leishmaniasis, transmissible venereal tumors, ehrlichiosis, rickettsiosis, or Chagas’ disease and sera from healthy dogs. The antigen was also tested with 227 samples of human sera, including sera from patients with visceral, cutaneous, or diffuse cutaneous leishmaniasis and from noninfected individuals, as well as sera from patients with Chagas’ disease, toxoplasmosis, rickettsiosis, hepatitis B, schistosomiasis, ascaridiasis, malaria, rheumatoid factor, leprosy and rheumatoid factor, tuberculosis, or leprosy. All dogs and all human patients had a clinical and/or serological and/or parasitological diagnosis. For detecting antibodies in sera from dogs with leishmaniasis, the antigen showed a sensitivity of 98%, specificity of 95%, and concordance of 93% and when used for detecting antibodies in human sera presented a sensitivity of 92%, specificity of 100%, and concordance of 92%. Comparison between ELISA and IFAT demonstrated that ELISA using the LMS antigen yielded more reliable results than IFAT. The LMS antigen displayed no cross-reactivity with sera from patients or dogs that had any of the other diseases tested.Item Poloxamer 407 (Pluronic® F127)-based polymeric micelles for amphotericin B : in vitro biological activity, toxicity and in vivo therapeutic efficacy against murine tegumentary leishmaniasis.(2016) Mendonça, Débora Vasconcelos Costa; Lage, Letícia Martins dos Reis; Lage, Daniela Pagliara; Chávez Fumagalli, Miguel Angel; Ribeiro, Fernanda Ludolf; Roatt, Bruno Mendes; Souza, Daniel Menezes; Faraco, André Augusto Gomes; Castilho, Rachel Oliveira; Tavares, Carlos Alberto Pereira; Barichello, José Mario; Duarte, Mariana Costa; Coelho, Eduardo Antônio FerrazIn the present study, a Poloxamer 407-based amphotericin B (AmpB)-containing polymeric micelles system (AmpB/M) was employed in the treatment of Leishmania amazonensis-infected BALB/c mice. Initially, the in vitro antileishmanial activity (IC50 value) of AmpB/M and B-AmpB/M (empty micelles) against stationary promastigotes and amastigotes-like forms of the parasites was determined, and results were of 1.83 ± 0.4 and 22.1 ± 0.7 mM, respectively, for the promastigotes, and of 2.27 ± 0.5 and 33.98 ± 2.6 mM, respectively, for the amastigotes-like. The cytotoxic concentration (CC50) values of these products were also evaluated, and we found the results of 119.5 ± 9.6 and 134.7 ± 10.3 mM, respectively. With these values, the selectivity index (SI) was calculated and results were of 65.3 and 5.4, respectively, for the promastigotes, and of 59.3 and 3.96, respectively, for the amastigotes-like of the parasites. Free AmpB showed IC50 values of 1.2 ± 0.3 and 2.5 ± 0.5 mM for the promastigotes and amastigotes-like, respectively, whereas the CC50 value was of 9.5 ± 0.4 mM. The SI values of this drug were of 7.9 and 3.8, respectively, for the promastigote and amastigote-like stages of the parasites. After, animals were infected and received saline or were treated subcutaneously with free AmpB, AmpB/M or B-AmpB/M. In the results, free AmpB-treated and infected mice showed reductions in their body weight, which were associated with hepatic and renal damage; however, no organic alteration was observed in the AmpB/Mtreated animals. In addition, these animals showed significant reductions in their lesion average size and in the parasite burden in all evaluated infected tissue and organs, when compared to the other groups; as well as significantly higher levels of antileishmanial IFN-g, IL-12, GM-CSF and nitrite, which were associated with low production of IL-4, IL-10 and IgG1 isotype antibodies. In conclusion, this AmpB/M system could be considered as an alternative for future studies in the treatment of tegumentary leishmaniasis.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.Item Treatment of murine visceral leishmaniasis using an 8-hydroxyquinoline-containing polymeric micelle system.(2016) Duarte, Mariana Costa; Lage, Letícia Martins dos Reis; Lage, Daniela Pagliara; Martins, Vivian Tamietti; Carvalho, Ana Maria Ravena Severino; Roatt, Bruno Mendes; Souza, Daniel Menezes; Tavares, Carlos Alberto Pereira; Alves, Ricardo José; Barichello, José Mario; Coelho, Eduardo Antônio FerrazNewtherapeutics are urgently needed to treat visceral leishmaniasis (VL). Due to the fact that drug discovery is a long and expensive process, the development of delivery systems to carry old and toxic drugs could be considered, as well as the evaluation of new molecules that have already shown to present biological activity. In this context, the present study evaluated the in vitro and in vivo antileishmanial activity of an 8-hydroxyquinoline (8-HQN)-containing polymeric micelle (8-HQN/M) system against Leishmania infantum, the main causative agent of VL in the Americas. The experimental strategy used was based on the evaluation of the parasite load by a limiting-dilution technique in the spleen, liver, bone marrow and draining lymph nodes of the infected and treated animals, as well as by a quantitative PCR (qPCR) technique to also assess the splenic parasite load. The immune response developed was evaluated by the production of IFN-γ, IL-4, IL-10, IL-12 and GM-CSF cytokines, as well as by antileishmanial nitrite dosage and antibodies production. Hepatic and renal enzymes were also investigated to verify cellular injury as a result of treatments toxicity. In the results, 8-HQN/M-treated mice, when compared to the other groups: saline, free amphotericin B (AmpB, as a drug control), 8-HQN and B-8-HQN/M (as a micelle control) showed more significant reductions in their parasite burden in all evaluated organs. These animals also showed an antileishmanial Th1 immunity, which was represented by high levels of IFN-γ, IL-12, GM-CSF and nitrite, associated with a low production of IL-4 and IL-10 and anti-Leishmania IgG1 isotype antibodies. In addition, any hepatic or renal damage was found in these treated animals. In conclusion, 8-HQN/M was effective in treating L. infantum-infected BALB/c mice, and can be considered alone, or combined with other drugs, as an alternative treatment for VL.