Navegando por Autor "Silveira, Patricia"
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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 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 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.