Navegando por Autor "Santos, Liliane Martins dos"
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Item Lactobacillus delbrueckii UFV-H2b20 increases IFN-γ production and CD39+CD73+ Treg cell numbers in lungs, and protects mice against experimental allergic asthma.(2022) Andrade, Ana Clara Matoso Montuori de; Silva, Ana Elisa Nolasco e; Malacco, Nathalia Luisa Sousa de Oliveira; Vaz, Leonardo Gomes; Afonso, Luís Carlos Crocco; Russo, Remo de Castro; Vieira, Leda Quercia; Santos, Liliane Martins dosAsthma is a disorder characterized by airflow obstruction, inflammation, declining airway function, bronchial hyperresponsiveness and tissue remodelling. Probiotics are defined as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”. The use of probiotics is becoming increasingly studied and recent evidence has suggested that it may provide therapeutic benefits in asthma and other diseases. Lactobacillus delbrueckii UFV-H2b20 fulfils all the requirements to be classified as probiotic. Previous studies have already shown the ability of L. delbrueckii UFV-H2b20 to stimulate the immune system. Our objective was to evaluate the protective effects of L. delbrueckii UFV-H2b20 in experimental allergic asthma. We used a murine model of ovalbumin-induced allergic airway inflammation to mimic allergic asthma. Oral treatment with L. delbrueckii UFV-H2b20 improves respiratory parameters and inhibits the inflammatory response in the lungs by decreasing the numbers of inflammatory monocytes, eosinophils and alveolar macrophages, as well as IgE levels. Treatment increased the IFN-γ/IL-4 cytokine ratio. Levels of IL-10 in the lungs were also increased in treated animals. Our results also showed that the probiotic administration increases the number of CD39+CD73+ T regulatory lymphocytes in the lung, suggesting a role for purinergic signals in the regulation of inflammation promoted by the treatment. Understanding the mechanisms of modulation of the immune system by probiotics could allow the development of probiotic preparations that are safe and have a direct action. Our results suggest that oral administration of L. delbrueckii UFV-H2b20 could be helpful to treat chronic inflammatory airway diseases, such as asthma.Item Lactobacillus delbrueckii UFV-H2b20 induces type 1 cytokine production by mouse cells in vitro and in vivo.(2009) Neumann, Elisabeth; Ramos, M. G.; Santos, Liliane Martins dos; Rodrigues, Ana Cristina Persichini; Vieira, Enio Carlos; Afonso, Luís Carlos Crocco; Nicoli, Jacques Robert; Vieira, Leda QuerciaItem Low and high-dose intradermal infection with Leishmania major and Leishmania amazonensis in C57BL/6 mice.(2010) Côrtes, Denise Fonseca; Carneiro, Matheus Batista Heitor; Santos, Liliane Martins dos; Souza, Talita Correia de Oliveira; Maioli, Tatiani Uceli; Duz, Ana Luiza Cassin; Jorge, Maria Letícia Ramos; Afonso, Luís Carlos Crocco; Carneiro, Cláudia Martins; Vieira, Leda QuerciaA model of skin infection with Leishmania amazonensis with low doses of parasites is compared to infection with high doses of L. amazonensis and low and high doses of Leishmania major. C57BL/6 mice were infected with 103 or 106 parasites in the ear and the outcome of infection was assessed. The appearance of lesions in mice infected with 103 parasites was delayed compared to mice infected with 106 Leishmania and parasites were detectable at the infection site before lesions became apparent. Mice infected with L. amazonensis displayed persistent lesions, whereas infection with L. major spontaneously healed in all groups, although lymphocytes persisted at the site of infection after healing. Macrophages persisted only in L. amazonensis-infected mice. High-dose L. amazonensis-infected mice produced lower levels of IFN-γ and TNF than mice infected with L. major. No correlation between the persistence of parasites and IL-10 levels and the production of nitric oxide or urea by macrophages was found. We conclude that infection with low doses of L. amazonensis in the dermis changes the course of infection by delaying the appearance of lesions. However, low-dose infection does not change the outcomes of susceptibility and cytokine production described for subcutaneous infection with high numbers of parasites.Item Short-term protection conferred by Leishvacin® against experimental Leishmania amazonensis infection in C57BL/6 mice.(2014) Carneiro, Matheus Batista Heitor; Sousa, Louisa Maria de Andrade e; Vaz, Leonardo Gomes; Santos, Liliane Martins dos; Vilela, Luciano; Souza, Carolina Carvalho de; Gonçalves, Ricardo; Tafuri, Wagner Luiz; Afonso, Luís Carlos Crocco; Côrtes, Denise Fonseca; Vieira, Leda QuerciaTo date, there is no vaccine available against human leishmaniasis. Although some vaccination protocols can induce immunity in murine models, they fail to induce protection in humans. The reasons for that remain unclear. The aimof the present study was to characterize the changes in the pattern of the immune response during subcutaneous vaccination with Leishvacin® in mice. We also investigated whether IFN-γ and nitric oxide synthase are indispensable for the protection elicited by the vaccine. C57BL/6 WT vaccinated mice showed smaller lesions and fewer numbers of parasites in footpads until 8 weeks post-infection. Up to this time, they produced higher levels of IFN-γ, IL-2, IL-4, IL-17A and IL-10 and higher specific antibody response than control non-vaccinated mice. Moreover, we showed that IFN-γ, most likely by induction of iNOS expression, is essential for immunity. However, after 12 weeks of infection, we observed loss of difference in lesion size and parasite burden between the groups. Loss of resistancewas associatedwith the disappearance of differences in cytokine patterns between vaccinated and control mice, but not of antibody response, which remained different until a later time of infection. The reversal of resistance to L. amazonensis could not be explained by upregulation of regulatory cytokines. Our data point to a subversion of the host immune response by L. amazonensis even when a protective response was previously induced.