Navegando por Palavras-chave "Toll-like receptor 4"
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- ItemAcesso aberto (Open Access)Além da atividade proteolítica das metaloproteases: atividade imunomoduladora da Thimet oligopeptidase (TOP) no tratamento do melanoma murino B16F10Nex2(Universidade Federal de São Paulo (UNIFESP), 2017-02-28) De Amat Herbozo, Carolina Cecilia [UNIFESP]; Rodrigues, Elaine Guadelupe [UNIFESP]; http://lattes.cnpq.br/6913514130496062; http://lattes.cnpq.br/9647501450376151; Universidade Federal de São Paulo (UNIFESP)Previous studies in our laboratory have shown that two bacterial metalloproteases, oligopeptidase A (OpdA) and arazyme, have antitumor activity. This property was independent of their proteolytic activity, and it was mediated by an immunomodulatory effect, involving the activation of antigen presenting cells (APCs). Those results could indicate that OpdA and arazyme were recognized by APCs because of their bacterial origin or otherwise, the immunomodulatory ability was a characteristic of metalloproteases in general, regardless of their origin. The aim of the present study was to evaluate the immunomodulatory and antitumor activity of thimet oligopeptidase (TOP), a murine metallopeptidase, in the B16F10-Nex2 murine melanoma model. Expression and purification of the recombinant version of TOP (rTOP) were optimized, and active and heat-inactivated forms were analyzed. rTOP did not show direct cytotoxic activity in vitro on tumor cells. In vivo assays showed that rTOP has a dose-dependent antitumor activity only in the metastatic, but not in the subcutaneous model. The antitumor effect was independent of the rTOP proteolytic activity, and dependent on a functional adaptive immune response, since it was abolished in immunodeficient animals. Cytokine analysis of serum samples and ex vivo restimulated spleen and lymph node cells revealed that a tumor-specific Th1 response was favored in rTOP treated animals. The active form of the metalloprotease stimulated an increase of IFN-γ, whereas the heat-inactivated form inhibited IL-10 production. Murine bone marrow-derived macrophages and dendritic cells (BMDMs and BMDCs, respectively), were activated in the presence of both active and inactive rTOP, resulting in increased NO production, IL-12p40, TNF-α and IL-10 secretion, and expression of the costimulatory molecules CD80, CD86 and CD40 in BMDCs. Assays in the presence of polymyxin B and with proteinase K-degraded metaloprotease demonstrated that the immunomodulatory activity of rTOP on APCs is not due to the residual LPS of the recombinant preparation. Assays with cells obtained from knockout mice or using specific antagonists/inhibitors determined that the activation of BMDCs is dependent on the presence and function of the TLR4 receptor and the MyD88 and TRIF adapters, and participation of the JNK, p38 and MAP/ERK kinases. In addition, the MyD88 pathway was essential for the antitumor effect of rTOP in the metastatic melanoma model in vivo. In conclusion, rTOP exhibits antitumor activity in the murine metastatic melanoma model mediated by an immunomodulatory effect, and the activation of APCs by rTOP requires the same receptor and signaling pathways as the bacterial metalloproteases studied before.
- ItemAcesso aberto (Open Access)Níveis de expressão gênica de TLR4 e MYD88 no sangue do receptor predizem o retardo na recuperação da função do enxerto renal de doadores falecidos(Universidade Federal de São Paulo (UNIFESP), 2010-09-29) Oliveira, Vinicius de Andrade [UNIFESP]; Gerbase-Lima, Maria [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Objetivo: investigar a participação da imunidade inata, através da análise de expressão dos genes TLR4 e MYD88, na disfunção precoce do enxerto renal em humanos. Métodos: A quantificação do mRNA foi realizada por PCR em tempo real, em biópsias pré-implantação do enxerto, na urina e no sangue (leucócitos) do primeiro dia póstransplante, em 75 transplantes (TX) com doador falecido (DF) e 18 transplantes com doador vivo (DV). Os desfechos considerados foram DGF (delayed graft function) e retardo na recuperação da função renal, independentemente de necessidade de diálise. Resultados: Em biópsias, os níveis de expressão de TLR4 e MyD88 foram maiores em rins de DF do que de DV; mas não se correlacionaram com disfunção precoce do enxerto; na urina, não diferiram entre DF e DV, e tenderam a ser mais elevados em casos de TX-DF com disfunção precoce do enxerto; no sangue, não diferiram entre DF e DV e foram mais baixos em casos com disfunção precoce. Conclusão: os resultados sugerem uma participação de TLR4 e MYD88 na patogenia das alterações que ocorrem em rins de DF e que baixos níveis de expressão gênica de TLR4 e MYD88, mensurados em amostra de leucócitos do sangue periférico colhida nas primeiras 24 horas pós-transplante, podem predizer retardo na recuperação da função do enxerto e, portanto, poderão vir a ter utilidade clínica no tratamento de receptores de transplante renal de doador falecido.
- ItemRestritoTLR-2 and TLR-4 expression in monocytes of newborns with late-onset sepsis(Soc Brasil Pediatria, 2014-09-01) Redondo, Ana Carolina Costa; Ceccon, Maria Esther Jurfest Rivero; Silveira-Lessa, Ana Lúcia; Quinello, Camila; Palmeira, Patricia; Carvalho, Werther Brunow [UNIFESP]; Carneiro-Sampaio, Magda Maria Sales; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)Objective: To analyze toll-like receptor (TLR)-2 and TLR-4 expression in monocytes of newborns with late-onset sepsis.Methods: This prospective study included 27 full-term newborns aged 8 to 29 days, with clinical and laboratory diagnosis of late-onset sepsis. Ten newborns (37%) had positive cultures. Cytokines were measured by cytometric bead array in peripheral blood, while TLR-2, TLR-4 expression, and median fluorescence intensity (MFI) were determined by immunophenotyping peripheral whole blood monocytes, and were analyzed with a BD FACSDiva flow cytometer (Becton, Dickinson and Company, USA). A comparison was performed with healthy adults.Results: Microorganisms were identified in 37% of these septic newborns, and all of them had high levels of pro-inflammatory cytokines (IL-8, IL-6, IL-1 beta) and anti-inflammatory cytokine (IL-10) corroborating the inflammatory/septic process. in monocytes, the frequency of TLR-4 expression was higher in infected newborns (p = 0.01).Conclusion: This study investigated the innate immune response in septic newborns. Septic newborns that relied almost exclusively on the innate immune system showed little in vivo response at nnonocyte activation, suggesting impaired immune response and increased susceptibility to infection. (C) 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.
- ItemSomente MetadadadosTLR4 and CD14 receptors expressed in rat pineal gland trigger NFKB pathway(Wiley-Blackwell, 2010-09-01) Cruz-Machado, Sanseray da Silveira; Carvalho-Sousa, Claudia Emanuele; Tamura, Eduardo Koji; Pinato, Luciana; Cecon, Erika; Magno Fernandes, Pedro Augusto Carlos; Avellar, Maria Christina Werneck [UNIFESP]; Ferreira, Zulma Silva; Markus, Regina Pekelmann; Universidade de São Paulo (USP); Univ Estadual Paulista; Universidade Federal de São Paulo (UNIFESP)Nuclear factor-kappa B (NFKB), a pivotal player in inflammatory responses, is constitutively expressed in the pineal gland. Corticosterone inhibits pineal NFKB leading to an enhancement of melatonin production, while tumor necrosis factor (TNF) leads to inhibition of Aa-nat transcription and the production of N-acetylserotonin in cultured glands. the reduction in nocturnal melatonin surge favors the mounting of the inflammatory response. Despite these data, there is no clear evidence of the ability of the pineal gland to recognize molecules that signal infection. This study investigated whether the rat pineal gland expresses receptors for lipopolysaccharide (LPS), the endotoxin from the membranes of Gram-negative bacteria, and to establish the mechanism of action of LPS. Here, we show that pineal glands possess both CD14 and toll-like receptor 4 (TLR4), membrane proteins that bind LPS and trigger the NFKB pathway. LPS induced the nuclear translocation of p50/p50 and p50/RELA dimers and the synthesis of TNF. the maximal expression of TNF in cultured glands coincides with an increase in the expression of TNF receptor 1 (TNFR1) in isolated pinealocytes. in addition, LPS inhibited the synthesis of N-acetylserotonin and melatonin. Therefore, the pineal gland transduces Gram-negative endotoxin stimulation by producing TNF and inhibiting melatonin synthesis. Here, we provide evidence to reinforce the idea of an immune-pineal axis, showing that the pineal gland is a constitutive player in the innate immune response.
- ItemAcesso aberto (Open Access)Topical Dexamethasone Administration Impairs Protein Synthesis and Neuronal Regeneration in the Olfactory Epithelium(Frontiers Media Sa, 2018) Crisafulli, Umberto [UNIFESP]; Xavier, Andre Machado [UNIFESP]; Santos, Fabiana B. dos [UNIFESP]; Cambiaghi, Tavane David [UNIFESP]; Chang, Seo Y. [UNIFESP]; Porcionatto, Marimélia Aparecida [UNIFESP]; Castilho, Beatriz Amaral de [UNIFESP]; Malnic, Bettina; Glezer, Isaias [UNIFESP]Chronic inflammatory process in the nasal mucosa is correlated with poor smell perception. Over-activation of immune cells in the olfactory epithelium (OE) is generally associated with loss of olfactory function, and topical steroidal anti-inflammatory drugs have been largely used for treating such condition. Whether this therapeutic strategy could directly affect the regenerative process in the OE remains unclear. In this study, we show that nasal topical application of dexamethasone (DEX