Navegando por Autor "Dutra, Walderez Ornelas"
Agora exibindo 1 - 11 de 11
Resultados por página
Opções de Ordenação
Item Canine visceral leishmaniasis biomarkers and their employment in vaccines.(2019) Giunchetti, Rodolfo Cordeiro; Silveira, Patricia; Resende, Lucilene Aparecida; Leite, Jaqueline Costa; Melo Júnior, Otoni Alves de Oliveira; Alves, Marina Luiza Rodrigues; Costa, Laís Moreira; Lair, Daniel Ferreira; Chaves, Vinícius Rossi; Soares, Ingrid dos Santos; Mendonça, Ludmila Zanandreis de; Lanna, Mariana Ferreira; Ribeiro, Helen Silva; Gonçalves, Ana Alice Maia; Santos, Thaiza Aline Pereira; Roatt, Bruno Mendes; Soares, Rodrigo Dian de Oliveira Aguiar; Souza, Juliana Vitoriano de; Moreira, Nádia das Dores; Siqueira, Fernando Augusto Mathias; Cardoso, Jamille Mirelle de Oliveira; Vital, Wendel Coura; Galdino, Alexsandro Sobreira; Viana, Kelvinson Fernandes; Martins Filho, Olindo Assis; Lemos, Denise da Silveira; Dutra, Walderez Ornelas; Reis, Alexandre BarbosaThe natural history of canine visceral leishmaniasis (CVL) has been well described, particularly with respect to the parasite load in different tissues and immunopathological changes according to the progression of clinical forms. The biomarkers evaluated in these studies provide support for the improvement of the tools used in developing vaccines against CVL. Thus, we describe the major studies using the dog model that supplies the rationale for including different biomarkers (tissue parasitism, histopathology, hematological changes, leucocytes immunophenotyping, cytokines patterns, and in vitro co-culture systems using purified T-cells subsets and macrophages infected with L. infantum) for immunogenicity and protection evaluations in phases I and II applied to pre-clinical and clinical vaccine trials against CVL. The search for biomarkers related to resistance or susceptibility has revealed a mixed cytokine profile with a prominent proinflammatory immune response as relevant for Leishmania replication at low levels as observed in asymptomatic dogs (highlighted by high levels of IFN-γ and TNF-α and decreased levels in IL-4, TGF-β and IL-10). Furthermore, increased levels in CD4+ and CD8+ T-cell subsets, presenting intracytoplasmic proinflammatory cytokine balance, have been associated with a resistance profile against CVL. In contrast, a polyclonal B-cell expansion towards plasma cell differentiation contributes to high antibody production, which is the hallmark of symptomatic dogs associated with high susceptibility in CVL. Finally, the different studies used to analyze biomarkers have been incorporated into vaccine immunogenicity and protection evaluations. Those biomarkers identified as resistance or susceptibility markers in CVL have been used to evaluate the vaccine performance against L. infantum in a kennel trial conducted before the field trial in an area known to be endemic for visceral leishmaniasis. This rationale has been a guiding force in the testing and selection of the best vaccine candidates against CVL and provides a way for the veterinary industry to register commercial immunobiological products.Item Captopril increases the intensity of monocyte infection by Trypanosoma cruzi and induces human T helper type 17 cells.(2010) Santos, Janete Soares Coelho dos; Menezes, Cristiane Alves da Silva; Villani, Fernanda Nobre Amaral; Magalhães, Luísa Mourão Dias; Scharfstein, Julio; Gollob, Kenneth John; Dutra, Walderez OrnelasThe anti-hypertensive drug captopril is used commonly to reduce blood pressure of patients with severe forms of Chagas disease, a cardiomyopathy caused by chronic infection with the intracellular protozoan Trypanosoma cruzi. Captopril acts by inhibiting angiotensin-converting enzyme (ACE), the vasopressor metallopeptidase that generates angiotensin II and promotes the degradation of bradykinin (BK). Recent studies in micemodels of Chagas disease indicated that captopril can potentiate the T helper type 1 (Th1)-directing natural adjuvant property of BK. Equipped with kinin-releasing cysteine proteases, T. cruzi trypomastigotes were shown previously to invade nonprofessional phagocytic cells, such as human endothelial cells and murine cardiomyocytes, through the signalling of G protein-coupled bradykinin receptors (B2KR). Monocytes are also parasitized by T. cruzi and these cells are known to be important for the host immune response during infection. Here we showed that captopril increases the intensity of T. cruzi infection of human monocytes in vitro. The increased parasitism was accompanied by up-regulated expression of ACE in human monocytes.While T. cruzi infection increased the expression of interleukin (IL)-10 by monocytes significantly, compared to uninfected cells, T. cruzi infection in association with captopril down-modulated IL-10 expression by the monocytes. Surprisingly, studies with peripheral blood mononuclear cells revealed that addition of the ACE inhibitor in association with T. cruzi increased expression of IL-17 by CD4+ T cells in a B2KR-dependent manner. Collectively, our results suggest that captopril might interfere with host–parasite equilibrium by enhancing infection of monocytes, decreasing the expression of the modulatory cytokine IL-10, while guiding development of the proinflammatory Th17 subset.Item Clinical aspects of Chagas disease and implications for novel therapies.(2011) Menezes, Cristiane Alves da Silva; Costa, Germano Carneiro; Gollob, Kenneth John; Dutra, Walderez OrnelasThe interaction between the protozoan parasite Trypanosoma cruzi and the human host dates back 9,000 years, as demonstrated by molecular analysis of material obtained from Andean mummies indicating the presence of the parasite’s kinetoplast DNA in populations from Chile and Peru. This long-established interaction, which persists today, demonstrates that T. cruzi has established a very well adapted relationship with the human host. From the point of view of a host–parasite relationship, this is desirable; however, such a high degree of adaptation is perhaps the foundation for many of the unknowns that surround this disease. Unveiling of the immunological mechanisms that underlie the establishment of pathology, identification of parasite-associated factors that determine strain-differential tissue tropism, discovery of host genetic elements that influence the development of different clinical forms of the disease, and understanding environmental factors that may influence the host–parasite interactions are some of the key questions that remain to be answered. The response to these questions will aid in addressing some of the current challenges in Chagas disease: fulfilling the need for efficient diagnosis, developing effective prophylactic measures, discovering effective therapeutics, and finding methods to control disease progression.Item Highly conserved CDR3 region in circulating CD4(+) Vβ5(+) T cells may be associated with cytotoxic activity in Chagas disease.(2012) Menezes, Cristiane Alves da Silva; Sullivan, A. K.; Falta, M. T.; Mack, D. G.; Freed, B. M.; Rocha, Manoel Otávio da Costa; Gollob, Kenneth John; Fontenot, A. P.; Dutra, Walderez OrnelasHuman infection with Trypanosoma cruzi leads to Chagas disease, which presents as several different clinical conditions ranging from an asymptomatic form to a severe dilated cardiomyopathy. Several studies have demonstrated that T cells play a critical role in the development of cardiac pathology, as well as in immunoregulation during chronic disease. However, the mechanisms that drive protective or pathogenic T cell response are not known.We have shown that CD4+ T cells from chagasic patients preferentially express T cell receptor (TCR) b-chain variable region (Vb) 5. The aim of this work was to determine whether T cells expressing this particular Vb region displayed variable or restricted CDR3 sequences, as an indicator of the nature of the stimulus leading to the activation of these T cells in vivo. Additionally, we aimed to evaluate phenotypic characteristics of these cells that might be associated with pathology. CDR3 junctional region sequencing of Vb5·1 expressing CD4+ T cells revealed the occurrence of a highly homologous CDR3 region with conserved TCR Jb region usage among patients with cardiac, but not indeterminate, Chagas disease. Moreover, correlation analysis indicated that the frequency of CD4+Vb5·1+ cells is associated with granzyme A expression, suggesting that these cells might display cytotoxic function. Together these results provide new insight into T cell recognition of antigens involved in Chagas disease and suggest that these cells may be implicated in the pathogenesis of chagasic cardiomyopathy.Item In vitro infectivity of strains isolated from dogs naturally infected with Leishmania infantum present a distinct pathogenic profile in hamsters.(2020) Resende, Lucilene Aparecida; Soares, Rodrigo Dian de Oliveira Aguiar; Moreira, Nádia das Dores; Ferreira, Sidney de Almeida; Lanna, Mariana Ferreira; Cardoso, Jamille Mirelle de Oliveira; Mathias, Fernando Augusto Siqueira; Vital, Wendel Coura; Mariano, Reysla Maria da Silveira; Leite, Jaqueline Costa; Silveira, Patricia; Carvalho, Tatiane Furtado de; Santos, Renato Lima; Lemos, Denise da Silveira; Martins Filho, Olindo Assis; Dutra, Walderez Ornelas; Reis, Alexandre Barbosa; Giunchetti, Rodolfo CordeiroVisceral leishmaniasis (VL) is a severe disease caused by Leishmania infantum. Dogs are the parasite’s main reservoir, favoring its transmission in the urban environment. The analysis of L. infantum from infected dogs contributes to the identification of more virulent parasites, thereby supporting basic and applied studies such as vaccinal and therapeutic strategies. We proposed the in vitro and in vivo characterization of L. infantum strains from naturally infected dogs from a VL endemic area based on an infectivity and pathogenicity analysis. DH82 canine macrophages were infected in vitro with different strains for infectivity analysis, showing distinct infectivity profiles. The strains that showed greater and lesser infectivity using in vitro analyses (616 and 614, respectively) were used to infect hamsters for pathogenicity analysis. The group infected with strain 616 showed 100% survival while the group infected with strain 614 showed 50% after seven months of follow up. Furthermore, the 614 strain induced more noticeable clinicopathological changes and biochemical abnormalities in liver function, along with high inflammation and parasite load in the liver and spleen. We confirmed high variability of infectivity and pathogenicity in L. infantum strains from infected dogs. The results support the belief that screening for L. infantum infectivity using in vitro experiments is inadequate when it comes to selecting the most pathogenic strain.Item Kinetics of phenotypic and functional changes in mouse models of sponge implants : rational selection to optimize protocols for specific biomolecules screening purposes.(2020) Lanna, Mariana Ferreira; Resende, Lucilene Aparecida; Soares, Rodrigo Dian de Oliveira Aguiar; Miranda, Marina Barcelos de; Mendonça, Ludmila Zanandreis de; Melo Júnior, Otoni Alves de Oliveira; Mariano, Reysla Maria da Silveira; Leite, Jaqueline Costa; Silveira, Patricia; Oliveira, Rodrigo Corrêa de; Dutra, Walderez Ornelas; Reis, Alexandre Barbosa; Martins Filho, Olindo Assis; Moura, Sandra Aparecida Lima de; Lemos, Denise da Silveira; Giunchetti, Rodolfo CordeiroThe sponge implant has been applied as an important in vivo model for the study of inflammatory processes as it induces the migration, proliferation, and accumulation of inflammatory cells, angiogenesis, and extracellular matrix deposition in its trabeculae. The characterization of immune events in sponge implants would be useful in identifying the immunological events that could support the selection of an appropriate experimental model (mouse strain) and time post-implant analysis in optimized protocols for novel applications of this model such as in biomolecules screening. Here, the changes in histological/morphometric, immunophenotypic and functional features of infiltrating leukocytes (LEU) were assessed in sponge implants for Swiss, BALB/c, and C57BL/6 mice. A gradual increase of fibrovascular stroma and a progressive decrease in LEU infiltration, mainly composed of polymorphonuclear cells with progressive shift toward mononuclear cells at late time-points were observed over time. Usually, Swiss mice presented a more prominent immune response with late mixed pattern (pro-inflammatory/anti-inflammatory: IL-2/IFN-γ/IL-4/IL-10/IL-17) of cytokine production. While BALB/c mice showed an early activation of the innate response with a controlled cytokine profile (low inflammatory potential), C57BL/6 mice presented a typical early pro-inflammatory (IL-6/TNF/IFN-γ) response with persistent neutrophilic involvement. A rational selection of the ideal time-point/mouse-lineage would avoid bias or tendentious results. Criteria such as low number of increased biomarkers, no recruitment of cytotoxic response, minor cytokine production, and lower biomarker connectivity (described as biomarker signature analysis and network analysis) guided the choice of the best time-point for each model (Day5/Swiss; Day7/BALB/c; Day6/C57BL/6) with wide application for screening purposes, such as identification of therapeutic biomolecules, selection of antigens/adjuvants, and follow-up of innate and adaptive immune response to vaccines candidates.Item Low levels of vasoactive intestinal peptide are associated with Chagas disease cardiomyopathy.(2013) Corrêa, Marielle Valério; Rocha, Manoel Otávio da Costa; Sousa, Giovane Rodrigo de; Nunes, Maria do Carmo Pereira; Gollob, Kenneth John; Dutra, Walderez Ornelas; Menezes, Cristiane Alves da SilvaThe interconnection between immune and neuroendocrine systems influences regulation of inflammatory responses. The possible relevance that this integrative response may have during the course of Chagas disease remains poorly characterized. In this context, our study was designed to determine the expression of vasoactive intestinal peptide (VIP), a neuropeptide with anti-inflammatory properties, in blood from the indeterminate and cardiac polarized forms of Chagas disease. Moreover, we determined whether the differential expression of VIP is associated with the development of cardiomyopathy in individuals infected with Trypanosoma cruzi. Finally, we analyzed gene polymorphisms of VIP receptors, VPAC1 and VPAC2, and performed correlation analysis of these polymorphisms with the different clinical forms of Chagas disease. Our results demonstrated that low plasma levels of VIP were associated with the cardiac morbidity in Chagas disease. Accordingly, correlation analysis showed that low plasma levels of VIP were associated with worse cardiac function, as determined by left ventricular ejection fraction and left ventricular diastolic diameter values. Polymorphism analysis showed a significant association between VPAC1 and the indeterminate form of Chagas disease development. Our data indicate that VIP expression and its receptors’ polymorphism may be important in determining susceptibility to progression from mild to severe forms of Chagas disease.Item Multicomponent LBSap vaccine displays immunological and parasitological profiles similar to those of Leish-Tec® and Leishmune® vaccines against visceral leishmaniasis.(2016) Mendonça, Ludmila Zanandreis de; Resende, Lucilene Aparecida; Lanna, Mariana Ferreira; Soares, Rodrigo Dian de Oliveira Aguiar; Roatt, Bruno Mendes; Castro, Renata Alves de Oliveira e; Batista, Maurício Azevedo; Lemos, Denise da Silveira; Estanislau, Juliana de Assis Silva Gomes; Fujiwara, Ricardo Toshio; Rezende, Simone Aparecida; Martins Filho, Olindo Assis; Oliveira, Rodrigo Corrêa de; Dutra, Walderez Ornelas; Reis, Alexandre Barbosa; Giunchetti, Rodolfo CordeiroBackground: In past years, many researchers have sought canine visceral leishmaniasis (CVL) prevention through the characterization of Leishmania antigens as vaccine candidates. Despite these efforts, there is still no efficient vaccine for CVL control. Methods: In the present study, we performed a pre-clinical vaccine trial using BALB/c mice to compare the effects of the multicomponent LBSap vaccine with those of Leish-Tec® and Leishmune®. Blood was collected to determine the frequency of peripheral blood cells and to evaluate hematologic and immunophenotypic parameters. Liver and spleen samples were collected for parasitological quantification, and spleen samples were used to access the cytokine profile. Results: When measuring total IgG and IgG1 anti-Leishmania levels after the third vaccination and L. infantum challenge, it was evident that all vaccines were able to induce humoral immune response. Regarding the innate immune response, increased levels of NK CD3-CD49+ cells were the hallmark of all vaccinated groups, whereas only the Leish-Tec® group displayed a high frequency of CD14+ monocytes after L. infantum challenge. Moreover, CD3+CD4+ T cells were the main circulating lymphocytes induced after L. infantum challenge with all evaluated vaccines. Importantly, after L. infantum challenge, splenocytes from the Leishmune® vaccine produced high levels of IL-2, whereas a prominent type 1 immune response was the hallmark of the LBSap vaccine, which presented high levels of IL-2, IL-6, TNF-α, and IFN-γ. The efficacy analysis using real-time polymerase chain reaction demonstrated a reduction in the parasitism in the spleen (Leishmune®: 64 %; LBSap: 42 %; and Leish-Tec®: 36 %) and liver (Leishmune®: 71 %; LBSap: 62 %; and Leish-Tec®: 48 %). Conclusions: The dataset led to the conclusion that the LBSap vaccination was able to induce immune and efficacy profiles comparable with those of commercial vaccines, thus demonstrating its potential as a promising vaccine candidate for visceral leishmaniasis control.Item Nanoformulations with Leishmania braziliensis antigens triggered controlled parasite burden in vaccinated golden hamster (Mesocricetus auratus) against visceral leishmaniasis.(2022) Ottino, Jennifer; Leite, Jaqueline Costa; Melo Júnior, Otoni Alves de Oliveira; Cabrera González, Marco Antonio; Carvalho, Tatiane Furtado de; Garcia, Giani Martins; Batista, Maurício Azevedo; Silveira, Patrícia; Cardoso, Mariana Santos; Bueno, Lilian Lacerda; Fujiwara, Ricardo Toshio; Santos, Renato Lima; Paes, Paulo Ricardo de Oliveira; Lemos, Denise da Silveira; Martins Filho, Olindo Assis; Galdino, Alexsandro Sobreira; Chávez Fumagalli, Miguel Angel; Dutra, Walderez Ornelas; Mosqueira, Vanessa Carla Furtado; Giunchetti, Rodolfo CordeiroLeishmaniasis is a widespread vector-borne disease in Brazil, with Leishmania (Leishmania) infantum as the primary etiological agent of visceral leishmaniasis (VL). Dogs are considered the main reservoir of this parasite, whose treatment in Brazil is restricted to the use of veterinary medicines, which do not promote a parasitological cure. Therefore, efficient vaccine development is the best approach to Canine Visceral Leishmaniasis (CVL) control. With this in mind, this study used hamsters (Mesocricetus auratus) as an experimental model in an anti-Leishmania preclinical vaccine trial to evaluate the safety, antigenicity, humoral response, and effects on tissue parasite load. Two novel formulations of nanoparticles made from poly(D, L-lactic) acid (PLA) polymer loading Leishmania braziliensis crude antigen (LB) exhibiting two different particle sizes were utilized: LBPSmG (570 nm) and LBPSmP (388 nm). The results showed that the nanoparticles were safe and harmless to hamsters and were antigenic with the induction in LBSap, LBPSmG, and LBPSmG groups of total anti-Leishmania IgG antibodies 30 days after challenge, which persists 200 days in LBSap and LBPSmP. At the same time, a less pronounced hepatosplenomegaly in LBSap, LBPSmG, and LBPSmP was found when compared to control groups, as well as a less pronounced inflammatory infiltrate and granuloma formation in the spleen. Furthermore, significant reductions of 84%, 81%, and 90% were observed in spleen parasite burden accessed by qPCR in the LBSap, LBPSmG, and LBPSmP groups, respectively. In this way, LBSap, LBPSmG, and LBPSmP formulations showed better results in vaccinated and L. infantum-challenged animals in further reducing parasitic load in the spleen and attenuating lesions in liver and splenic tissues. This results in safe, harmless nanoformulation vaccines with significant immunogenic and infection control potential. In addition, animals vaccinated with LBPSmP had an overall reduction in parasite burden in the spleen, indicating that a smaller nanoparticle could be more efficient in targeting antigen-presenting cells.Item Prognosis of chronic Chagas heart disease and other pending clinical challenges.(2022) Torres, Rosália Morais; Correia, Dalmo; Nunes, Maria do Carmo Pereira; Dutra, Walderez Ornelas; Silva, André Talvani Pedrosa da; Sousa, Andréa Silvestre; Mendes, Fernanda de Souza Nogueira Sardinha; Scanavacca, Maurício Ibrahim; Pisani, Cristiano; Moreira, Maria da Consolação Vieira; Souza, Dilma do Socorro Moraes de; Oliveira Junior, Wilson de; Martins, Silvia Marinho; Dias, João Carlos PintoIn this chapter, the main prognostic markers of Chagas heart disease are addressed, with an emphasis on the most recent findings and questions, establishing the basis for a broad discussion of recommendations and new approaches to managing Chagas cardiopathy. The main biological and genetic markers and the contribution of the electrocardiogram, echocardiogram and cardiac magnetic resonance are presented. We also discuss the most recent therapeutic proposals for heart failure, thromboembolism and arrhythmias, as well as current experience in heart transplantation in patients suffering from severe Chagas cardiomyopathy. The clinical and epidemiological challenges introduced by acute Chagas disease due to oral contamination are discussed. In addition, we highlight the importance of ageing and comorbidities in influencing the outcome of chronic Chagas heart disease. Finally, we discuss the importance of public policies, the vital role of funding agencies, universities, the scientific community and health professionals, and the application of new technologies in finding solutions for better management of Chagas heart disease.Item Vaccination with formulation of nanoparticles loaded with Leishmania amazonensis antigens confers protection against experimental visceral leishmaniasis in hamster.(2023) Cabrera González, Marco Antonio; Gonçalves, Ana Alice Maia; Ottino, Jennifer; Leite, Jaqueline Costa; Resende, Lucilene Aparecida; Melo Júnior, Otoni Alves de Oliveira; Silveira, Patricia; Cardoso, Mariana Santos; Fujiwara, Ricardo Toshio; Bueno, Lilian Lacerda; Santos, Renato Lima; Carvalho, Tatiane Furtado de; Garcia, Giani Martins; Paes, Paulo Ricardo de Oliveira; Galdino, Alexsandro Sobreira; Chávez Fumagalli, Miguel Angel; Melo, Marilia Martins; Lemos, Denise da Silveira; Martins Filho, Olindo Assis; Dutra, Walderez Ornelas; Mosqueira, Vanessa Carla Furtado; Giunchetti, Rodolfo CordeiroVisceral leishmaniasis (VL) is a fatal disease caused by the protozoa Leishmania infantum for which dogs are the main reservoirs. A vaccine against canine visceral leishmaniasis (CVL) could be an important tool in the control of human and CVL by reducing the infection pressure of L. infantum. Despite the CVL vaccine available on the market, the Brazilian Ministry of Health did not implement the use of it in their control programs. In this sense, there is an urgent need to develop more efficient vaccines. In this study, the association between two polymeric nanoformulations, (poly (D, L-lactic) acid (PLA) polymer) loading Leishmania amazonensis antigens, was evaluated as a potential immunobiological agent against VL using golden hamsters as an experimental model. The results indicated that no significant adverse reactions were observed in animals vaccinated with LAPSmP. LAPSmP presented similar levels of total anti-Leishmania IgG as compared to LAPSmG. The LAPSmP and LAPSmG groups showed an intense reduction in liver and spleen parasitic load by qPCR. The LAPSmP and LAPSmG vaccines showed exceptional results, indicating that they may be promising candidates as a VL vaccine.