Navegando por Autor "Moreira, Gabriel José Lucas"
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Item Down regulation of IL-10 and TGF-β1 mRNA expression associated with reduced inflammatory process correlates with control of parasitism in the liver after treating L. infantum infected dogs with the LBMPL vaccine therapy.(2022) Roatt, Bruno Mendes; Cardoso, Jamille Mirelle de Oliveira; Brito, Rory Cristiane Fortes de; Reis, Levi Eduardo Soares; Moreira, Gabriel José Lucas; Vieira, Paula Melo de Abreu; Souza, Flávia Marques de; Lima, Wanderson Geraldo de; Soares, Rodrigo Dian de Oliveira Aguiar; Giunchetti, Rodolfo Cordeiro; Reis, Alexandre BarbosaThe liver plays an important role in human and canine visceral leishmaniasis, then it is considered as target to understand the mechanisms involved in the parasite control and a parameter to assess therapeutic responses. In this sense, our study focuses on evaluating the major alterations in the liver by histological (morphometric parenchyma inflammation/semi-quantitative portal inflammation), immunohistochemical assays (parasitism), and qPCR (parasitism and cytokine gene expression) in Leishmania infantum naturally infected dogs and treated with LBMPL vaccine. Animals were divided in four groups: NI group (n = 5): uninfected and untreated dogs; INT group (n = 7): L. infantum-infected dogs and not treated; MPL group (n = 6): L. infantum-infected dogs that received only monophosphoryl lipid A adjuvant, and LBMPL group (n = 10): L. infantum-infected dogs that received treatment with the vaccine composed by L. braziliensis disrupted promastigotes associated with MPL adjuvant. Ninety days after the end of treatments, the dogs were euthanized, and the liver was collected for the proposed evaluations. Significantly lower portal inflammatory reactions, and lower parenchyma inflammation were observed in the LBMPL group compared to INT and MPL groups. iNOS mRNA expression was higher in LBMPL group and in contrast, IL-10 and TGF-β1 mRNA expression was lower in this group when compared to INT group. Immunohistochemical and qPCR analysis showed significant parasite load reduction in LBMPL group compared to INT and MPL animals. Our data suggest that in naturally Leishmania-infected dogs, LBMPL vaccine reduces the damage in the hepatic tissue, being able to attenuate the type 2 immune response. It could be associated with a marked reduction in the parasitism decreasing liver inflammation in treated dogs. Along with previously obtained data, our results suggest that LBMPL vaccine can significantly contribute to the therapy strategy for L. infantum infected dogs.Item Immunoprophylaxis using polypeptide chimera vaccines plus adjuvant system promote Th1 response controlling the spleen parasitism in hamster model of visceral leishmaniasis.(2022) Gusmão, Miriã Rodrigues; Ostolin, Thais Lopes Valentim Di Paschoale; Carvalho, Lívia Mendes; Costa, Ana Flávia Pereira; Moreira, Gabriel José Lucas; Cardoso, Jamille Mirelle de Oliveira; Soares, Rodrigo Dian de Oliveira Aguiar; Reis, Alexandre Barbosa; Brito, Rory Cristiane Fortes de; Roatt, Bruno MendesIn recent years, several advances have been observed in vaccinology especially for neglected tropical diseases (NTDs). One of the tools employed is epitope prediction by immunoinformatic approaches that reduce the time and cost to develop a vaccine. In this scenario, immunoinformatics is being more often used to develop vaccines for NTDs, in particular visceral leishmaniasis (VL) which is proven not to have an effective vaccine yet. Based on that, in a previous study, two predicted T-cell multi-epitope chimera vaccines were experimentally validated in BALB/c mice to evaluate the immunogenicity, central and effector memory and protection against VL. Considering the results obtained in the mouse model, we assessed the immune response of these chimeras in Mesocricetus auratus hamster, which displays, experimentally, similar pathological status to human and dog VL disease. Our findings indicate that both chimeras lead to a dominant Th1 response profile, inducing a strong cellular response by increasing the production of IFN-c and TNF-a cytokines associated with a decrease in IL-10. Also, the chimeras reduced the spleen parasite load and the weight a correlation between protector immunological mechanisms and consistent reduction of the parasitic load was observed. Our results demonstrate that both chimeras were immunogenic and corroborate with findings in the mouse model. Therefore, we reinforce the use of the hamster as a pre-clinical model in vaccination trials for canine and human VL and the importance of immunoinformatic to identify epitopes to design vaccines for this important neglected disease.Item LBMPL vaccine therapy induces progressive organization of the spleen microarchitecture, improved Th1 adaptative immune response and control of parasitism in Leishmania infantum naturally infected dogs.(2022) Roatt, Bruno Mendes; Cardoso, Jamille Mirelle de Oliveira; Reis, Levi Eduardo Soares; Moreira, Gabriel José Lucas; Gonçalves, Letícia Captein; Marques, Flávia de Souza; Moreira, Nádia das Dores; Vieira, Paula Melo de Abreu; Soares, Rodrigo Dian de Oliveira Aguiar; Giunchetti, Rodolfo Cordeiro; Reis, Alexandre BarbosaThe spleen plays a central role in human and canine visceral leishmaniasis, where the activation of the immune response occurs in one of the tissues where Leishmania infantum reproduces. Therefore, this organ is both a target to understand the mechanisms involved in the parasite control and a parameter for assessing the therapeutic response. In this sense, this study aimed to evaluate the main histological, immunological and parasitological aspects in the spleen of symptomatic dogs naturally infected by L. infantum treated with the therapeutic vaccine LBMPL. For this, dogs were divided into four groups: dogs uninfected and untreated (NI group); L. infantum-infected dogs that were not treated (INT group); L. infantum-infected dogs that received treatment only with monophosphoryl lipid A adjuvant (MPL group); and L. infantum-infected dogs that received treatment with the vaccine composed by L. braziliensis promastigote proteins associated with MPL adjuvant (LBMPL group). Ninety days after the therapeutics protocol, the dogs were euthanized and the spleen was collected for the proposed evaluations. Our results demonstrated a reduction of hyperplasia of red pulp and follicular area of white pulp, increased mRNA expression of IFN-γ, TNF-α, IL-12 and iNOS, and decreased IL-10 and TGF-β1, and intense reduction of splenic parasitism in dogs treated with the LBMPL vaccine. These results possibly suggest that the pro-inflammatory environment promoted the progressive organization of the splenic architecture favoring the cellular activation, with consequent parasite control. Along with previously obtained data, our results propose the LBMPL vaccine as a possible treatment strategy for canine visceral leishmaniasis (CVL).