Navegando por Autor "Oliveira, Daniela Silva de"

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Ectonucleotidases from trypomastigotes from different sources and various genetic backgrounds of Trypanosoma cruzi potentiate their infectivity and host inflammation.
(2020) Leite, Ana Luísa Junqueira; Oliveira, Daniela Silva de; Mota, Ludmilla Walter Reis; Carvalho, Luana Cristina Faria; Zimmermann, Fernanda Francine; Paiva, Nívia Carolina Nogueira de; Vieira, Paula Melo de Abreu; Lana, Marta de; Afonso, Luís Carlos Crocco; Silva, André Talvani Pedrosa da
Distinct populations of Trypanosoma cruzi interact with mammalian cardiac muscle cells causing different inflammation patterns and low heart functionality. During T. cruzi infection, the extracellular ATP is hydrolyzed to tri- and/or diphosphate nucleotides, based on the infectivity, virulence, and regulation of the inflammatory response. T. cruzi carries out this hydrolysis through the T. cruzi ectonucleotidase, NTPDase-1 (TcNTPDase-1). This study aimed to evaluate the role of TcNTPDase-1 in culture rich in metacyclic trypomastigote forms (MT) and cell culture-derived trypomastigote forms (CT) from Colombiana (discrete typing unit - DTU I), VL-10 (DTU II), and CL (DTU VI) strains of T. cruzi. For this, we measured TcNTPDase-1 activity in suramin-treated and untreated parasites and infected J774 cells and C57BL/6 mice with suramin pre-treated parasites to assess parasitic and inflammatory cardiac profile in the acute phase of infection. Our data indicated a higher TcNTPDase-1 activity for ATP in culture rich in metacyclic trypomastigote forms from Colombiana strain in comparison to those from VL-10 and CL strains. The cell culture-derived trypomastigote forms from CL strain presented higher capacity to hydrolyze ATP than those from Colombiana and VL-10 strains. Suramin inhibited ATP hydrolysis in all studied parasite forms and strains. Suramin pre-treated parasites reduced J774 cell infection and increased nitrite production in vitro. In vivo studies showed a reduction of inflammatory infiltrate in the cardiac tissues of animals infected with cell culture-derived trypomastigote forms from suramin pre-treated Colombiana strain. In conclusion, TcNTPDase-1 activity in trypomastigotes forms drives part of the biological characteristics observed in distinct DTUs and may induce cardiac pathogenesis during T. cruzi infection.
A high-fat diet exacerbates the course of experimental Trypanosoma cruzi infection that can be mitigated by treatment with Simvastatin.
(2020) Souza, Débora Maria Soares de; Costa, Guilherme de Paula; Leite, Ana Luísa Junqueira; Oliveira, Daniela Silva de; Pinto, Kelerson Mauro de Castro; Farias, Sílvia Elvira Barros; Simões, Natália Figueira; Paiva, Nívia Carolina Nogueira de; Vieira, Paula Melo de Abreu; Silva, Camilo Adalton Mariano da; Figueiredo, Vivian Paulino; Menezes, Ana Paula de Jesus; Silva, André Talvani Pedrosa da
The protozoan Trypanosoma cruzi is responsible for triggering a damage immune response in the host cardiovascular system. This parasite has a high affinity for host lipoproteins and uses the low-density lipoprotein (LDL) receptor for its invasion. Assuming that the presence of LDL cholesterol in tissues could facilitate T. cruzi proliferation, dietary composition may affect the parasite-host relationship. Therefore, the aim of this study was to evaluate myocarditis in T. cruzi-infected C57BL/6 mice—acute phase—fed a high-fat diet and treated with simvastatin, a lipid-lowering medication. Animals (n = 10) were infected with 5 × 103 cells of the VL-10 strain of T. cruzi and treated or untreated daily with 20 mg/kg simvastatin, starting 24 h after infection and fed with a normolipidic or high-fat diet. Also, uninfected mice, treated or not with simvastatin and fed with normolipidic or high-fat diet, were evaluated as control groups. Analyses to measure the production of chemokine (C-C motif) ligand 2 (CCL2), interferon- (IFN-) γ, interleukin- (IL-) 10, and tumor necrosis factor (TNF); total hepatic lipid dosage; cholesterol; and fractions, as well as histopathological analysis, were performed on day 30 using cardiac and fat tissues. Our results showed that the high-fat diet increased (i) parasite replication, (ii) fat accumulation in the liver, (iii) total cholesterol and LDL levels, and (iv) the host inflammatory state through the production of the cytokine TNF. However, simvastatin only reduced the production of CCL2 but not that of other inflammatory mediators or biochemical parameters. Together, our data suggest that the high-fat diet may have worsened the biochemical parameters of the uninfected and T. cruzi-infected animals, as well as favored the survival of circulating parasites.
Insights into IL-33 on inflammatory response during in vitro infection by Trypanosoma cruzi.
(2022) Oliveira, Daniela Silva de; Leite, Ana Luísa Junqueira; Pedrosa, Tamiles Caroline Fernandes; Mota, Ludmilla Walter Reis; Costa, Guilherme de Paula; Souza, Débora Maria Soares de; Perucci, Luiza Oliveira; Silva, André Talvani Pedrosa da
Inflammatory and regulatory cytokines play an important role in the immunopathogenesis of Trypanosoma cruzi infection. Interleukin (IL)-33 is a member of the IL-1 superfamily of cytokines whose expression/production is upregulated following pro-inflammatory stimulation to alert the immune system in response to tissue stress or damage. The aim of this study was to evaluate the inflammatory profile induced in cultured J774 cells stimulated or not with IL-33 (10 ng/mL), with live parasites (1 × 106 metacyclic trypomastigote forms) and/or total antigen, TcAg (100 μg/mL) and with both, IL-33 and TcAg/T. cruzi. The cultures were evaluated at 24 h and 48 h after addition of the stimuli. For this, the supernatants were collected for the measurement of TNF, IL-17, CCL2, and IL-10 by ELISA and of nitrite by the Griess method. TNF, IL-17, and CCL2 concentrations were elevated in the presence of TcAg or live T. cruzi parasites at 24 h, and the addition of IL-33 potentiated these effects at 48 h. In addition, the T. cruzi-amastigote forms reduced in those infected J774 cells stimulated with IL-33 at 48 h. In conclusion, the IL-33 elevated the production of the TNF, IL-17, and CCL2 in cultured J774 cells stimulated with T. cruzi and/or its antigen and reduced the intracellular parasites, providing impetus to new investigations on its potential actions on the parasite-induced inflammation.
Perfil de mediadores inflamatórios produzido por células da linhagem J774 após estímulo in vitro com a IL-33 e antígeno/parasito o Trypanosoma cruzi.
(2020) Oliveira, Daniela Silva de; Silva, André Talvani Pedrosa da; Perucci, Luiza Oliveira; Silva, André Talvani Pedrosa da; Perucci, Luiza Oliveira; Estanislau, Juliana de Assis Silva Gomes; Isoldi, Mauro César
Na infecção pelo protozoário Trypanosoma cruzi, citocinas de perfil inflamatório exercem importante papel na imunopatogênese, enquanto outras apresentam suas ações ainda incertas, como é o caso da interleucina (IL)-33. O objetivo deste estudo é avaliar o perfil de resposta inflamatória induzido por células de cultura estimuladas com a IL-33 e com o T. cruzi (parasito vivo e antígenos – Ags). Na etapa I, Ags obtidos de parasitos da cepa Y do T. cruzi em diferentes concentrações (0; 12,5; 25; 50; 100 e 200 µg/mL) foram utilizados para estimular células da linhagem J774, após 24h, sendo o sobrenadante coletado para a dosagem do TNF (fator de necrose tumoral) por imunoensaio enzimático (ELISA). Assim, a dose selecionada foi a de 100µg para estimular as células. Na etapa II, realizou-se o cultivo de células J774 adicionando 5x105 células/poço para o estímulo com antígeno. Na etapa III foram plaqueadas cerca de 1,25x105 células/poço utilizando1x106 formas tripomastigotas metaciclícas do T. cruzi como estímulo. Os estímulos seguiram o seguinte padrão: (i) cultura sem IL-33 e sem antígeno/T. cruzi; (ii) cultura com IL-33 (10 ng/ml) e sem antígeno/T. cruzi; (iii) cultura sem IL-33 com antígeno (100µg/mL) e T. cruzi; (iv) cultura com IL-33 (10ng/ml) e com antígeno (100µg/mL) e T. cruzi. As culturas foram avaliadas em diferentes tempos após os estímulos, sendo eles 0h, 24h e 48h e os sobrenadantes coletados para dosagem dos mediadores inflamatórios: TNF, IL-17 (interleucina 17), CCL2 (ligante 2 da quimiocina do grupo CC), IL-10 (interleucina 10), dosagem de nitrito pelo método de Griess e contagem de amastigotas. Observou-se diferenças na produção do TNF, IL-17, CCL2 para os grupos estimulados pelo antígeno ou pelo T. cruzi nos tempos de 24h e 48h. Para a citocina IL-10, essas diferenças foram observadas apenas nos grupos estimulados com o T. cruzi. Em relação ao nitrito, observou-se diferenças nos grupos estimulados com Ag ou T. cruzi paras os tempos 0h, 24h e 48h. O número de formas amastigotas foi maior nas células estimuladas com a citocina IL-33. De forma geral, tanto o antígeno quanto o T. cruzi vivo, induziu a produção de mediadores inflamatórios nas células J774 com 24h ou de 48h. A IL-33 mostrou-se importante nos eventos iniciais da infecção tanto em células estimuladas com o Ag quanto com o parasito vivo, bem como no controle da citocina IL-10 nos grupos infectados. Dessa forma, concluímos que a citocina IL-33 durante a infecção in vitro pelo T. cruzi, em cultura de células J774, participa na produção de mediadores inflamatórios e regulatórios.