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1.
J Immunol Res ; 2019: 1790908, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31886295

RESUMO

The glycoprotein gp43 is the major antigenic/diagnostic component of Paracoccidioides brasiliensis, one of the etiologic agents of paracoccidioidomycosis (PCM). Gp43 has protective roles in mice, but due to adhesive properties, this glycoprotein has also been associated with immune evasion mechanisms. The present study evaluated gp43 interaction in vitro with Toll-like receptors 2 and 4 (TLR2 and TLR4) present in polymorphonuclear neutrophils (PMNs) from healthy human individuals and the consequent modulation of the immune response through the expression and release of cytokines and eicosanoids. PMNs were incubated in the absence or presence of monoclonal antibodies anti-TLR2 and anti-TLR4 (individually or in combination) before gp43 stimulation. Then, PMNs were analyzed for the expression of both surface receptors and the detection of intracytoplasmic IL-17A and IL-4 using flow cytometry, while the production of PGE2, LTB4, IL-6, IL-10, IL-12, IFN-γ, and TNF-α was evaluated in the supernatants by enzyme-linked immunosorbent assay (ELISA). Our results showed that gp43 increased TLR2 and TLR4 expression by PMNs and induced PGE2 and IL-17A via TLR4 and TLR2, respectively. Thus, our data suggest that gp43 from P. brasiliensis might modulate host susceptibility to the fungal infection by affecting PGE2 and IL-17A production.


Assuntos
Antígenos de Fungos/imunologia , Dinoprostona/metabolismo , Proteínas Fúngicas/imunologia , Interleucina-17/metabolismo , Neutrófilos/imunologia , Neutrófilos/metabolismo , Paracoccidioides/imunologia , Paracoccidioidomicose/imunologia , Paracoccidioidomicose/metabolismo , Adulto , Biomarcadores , Citocinas/biossíntese , Feminino , Expressão Gênica , Humanos , Mediadores da Inflamação/metabolismo , Masculino , Paracoccidioidomicose/genética , Paracoccidioidomicose/microbiologia , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Adulto Jovem
2.
J Immunol Res ; 2019: 1529189, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30882002

RESUMO

Paracoccidioidomycosis (PCM), a systemic mycosis endemic in Latin America, occurs after inhalation of mycelial components of Paracoccidioides spp. When the fungus reaches the lungs and interacts with the alveolar macrophages and other cells, phagocytic cells such as neutrophils and monocytes are immediately recruited to the injured site. The interaction between surface molecules of pathogens and homologous receptors, present on the surface membrane of phagocytes, modulates the innate immune cell activation. Studies have shown the importance of fungal recognition by the Dectin-1 receptor, which can induce a series of cellular protective responses against fungi. The objective of the present study was to evaluate Dectin-1 receptor expression and the effector mechanisms of human monocytes and neutrophils activated or not with different cytokines, such as IFN-γ, TNF-α, and GM-CSF, followed by the challenge with Paracoccidioides brasiliensis (P. brasiliensis or Pb265). Therefore, analysis of Dectin-1 receptor expression was done by flow cytometry whereas the effector mechanisms were evaluated by fungal recovery by colony-forming unit (CFU) counting and hydrogen peroxide (H2O2) production. Our results showed that, after treatment with IFN-γ, TNF-α, and GM-CSF and challenge with Pb265, cells, especially monocytes, demonstrated an increase in Dectin-1 expression. Both types of cells treated with the cytokines exhibited a decreased fungal recovery and, conversely, an increased production of H2O2. However, when cultures were treated with an anti-Dectin-1 monoclonal antibody, to block the P. brasiliensis binding, a decrease in H2O2 production and an increase in fungal recovery were detected. This effect was observed in all cultures treated with the specific monoclonal antibody. These results show the involvement of the Dectin-1 receptor in fungal recognition and its consequent participation in the induction of the killing mechanisms against P. brasiliensis.


Assuntos
Citocinas/farmacologia , Lectinas Tipo C/metabolismo , Paracoccidioidomicose/imunologia , Fagócitos/imunologia , Contagem de Colônia Microbiana , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Humanos , Peróxido de Hidrogênio/análise , Interferon gama/farmacologia , Lectinas Tipo C/genética , Masculino , Monócitos/efeitos dos fármacos , Monócitos/imunologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/imunologia , Paracoccidioides , Fagócitos/efeitos dos fármacos
3.
Mycoses ; 61(4): 222-230, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29110339

RESUMO

Fungal recognition by Dectin-1 receptor triggers a series of cellular mechanisms involved in a protective activation of the immune system. In this study, we aimed to evaluate the participation of Dectin-1 receptor in the induction of IL-8, TNF-α, IL-12, IL-10 and IL-17A secretion by human monocytes activated with different cytokines, and challenged in vitro with Paracoccidioides brasiliensis (P. brasiliensis). Our results show that monocytes challenged with P. brasiliensis (Pb265) are able to produce IL-12, IL-8, IL-17, IL-10 and TNF-α. Dectin-1 receptor blockage decreased the IL-12, IL-17, IL-10 and TNF-α levels indicating the participation of such receptor in the induction of these cytokines. Only IL-8 production was not affected by the blockage. Cells activation with different cytokines showed that GM-CSF was able to induce secretion of all cytokines and the receptor blockage prior to the challenge also decreased the cytokine secretion, except IL-8. Monocytes activated with TNF-α promoted IL-8, IL-10 and TNF-α production, whereas stimulation with IFN-γ promoted mainly IL-12 and TNF-α. Thus, these findings bring new and important knowledge about Dectin-1 participation in cytokines production by monocytes challenged with Pb265.


Assuntos
Citocinas/metabolismo , Lectinas Tipo C/metabolismo , Monócitos/imunologia , Monócitos/microbiologia , Paracoccidioides/imunologia , Adulto , Células Cultivadas , Humanos , Pessoa de Meia-Idade , Adulto Jovem
4.
J Appl Oral Sci ; 25(3): 265-273, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28678945

RESUMO

Objective: The aim of this study was to investigate the influence of aging on the internalization and the production of nitric oxide (NO) by peritoneal adherent cells (PAC), in response to Candida albicans (C. albicans). Material and methods: PAC obtained from young and aged mice were challenged with dead or viable C. albicans by using predetermined proportions (cells:yeast) for 30 and 120 minutes. Phagocytosis was analyzed by acridine orange dye, and NO production by the Griess reaction. Results: C. albicans phagocytosis by PAC from aged mice was similar to that of young mice, although the cells from older mice cells present more internalized fungi compared with matched control. In addition, a tendency towards impaired NO production by peritoneal mononuclear phagocytes from aged mice was observed. Conclusions: PAC from aged mice may capture and store many fungi, which in turn may mean that these cells are effectively unable to eliminate fungi, probably due to impaired NO production. Therefore, considering the important role of C. albicans overgrowth in the pathogenesis of DS and the aspects observed in this study, aging may favor the onset and severity of local candidosis such as DS and its systemic forms.


Assuntos
Envelhecimento/fisiologia , Candida albicans/patogenicidade , Adesão Celular/fisiologia , Óxido Nítrico/biossíntese , Fagocitose/fisiologia , Estomatite sob Prótese/metabolismo , Estomatite sob Prótese/microbiologia , Fatores Etários , Animais , Candida albicans/isolamento & purificação , Candidíase/microbiologia , Masculino , Camundongos Endogâmicos C57BL , Óxido Nítrico/análise , Peritônio/citologia , Valores de Referência , Fatores de Tempo
5.
J. appl. oral sci ; 25(3): 265-273, May-June 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-893620

RESUMO

Abstract Elderly denture wearers are commonly affected by Candida-associated denture stomatitis (DS), an inflammatory process of the oral mucosa strongly associated with Candida spp and other microorganisms, as well as local and systemic factors. The impaired immune response against pathogens is among the inherent host factors that have been also associated with the pathogenesis of DS. Mononuclear phagocytes respond to the pathogens through phagocytosis followed by the production of several substances inside the phagosomes, among them are the reactive nitrogen species (RNS). A failure in these mechanisms may contribute to the DS development. Objective The aim of this study was to investigate the influence of aging on the internalization and the production of nitric oxide (NO) by peritoneal adherent cells (PAC), in response to Candida albicans (C. albicans). Material and methods PAC obtained from young and aged mice were challenged with dead or viable C. albicans by using predetermined proportions (cells:yeast) for 30 and 120 minutes. Phagocytosis was analyzed by acridine orange dye, and NO production by the Griess reaction. Results C. albicans phagocytosis by PAC from aged mice was similar to that of young mice, although the cells from older mice cells present more internalized fungi compared with matched control. In addition, a tendency towards impaired NO production by peritoneal mononuclear phagocytes from aged mice was observed. Conclusions PAC from aged mice may capture and store many fungi, which in turn may mean that these cells are effectively unable to eliminate fungi, probably due to impaired NO production. Therefore, considering the important role of C. albicans overgrowth in the pathogenesis of DS and the aspects observed in this study, aging may favor the onset and severity of local candidosis such as DS and its systemic forms.


Assuntos
Animais , Masculino , Fagocitose/fisiologia , Estomatite sob Prótese/metabolismo , Estomatite sob Prótese/microbiologia , Candida albicans/patogenicidade , Envelhecimento/fisiologia , Adesão Celular/fisiologia , Óxido Nítrico/biossíntese , Peritônio/citologia , Valores de Referência , Fatores de Tempo , Candida albicans/isolamento & purificação , Candidíase/microbiologia , Fatores Etários , Camundongos Endogâmicos C57BL , Óxido Nítrico/análise
6.
Bauru; s.n; 2014. 131 p. ilus, tab, graf.
Tese em Português | BBO - Odontologia | ID: biblio-867045

RESUMO

Atualmente, a população mundial está passando por um processo de transição demográfica, relacionado com o aumento considerável do número de idosos em relação aos jovens. O rápido crescimento da população idosa constitui uma das maiores preocupações da sociedade moderna, o que demanda um aumento no estudo da saúde e da melhoria da qualidade de vida dos idosos, incluindo um maior esclarecimento dos aspectos patofisiológicos relacionados com as doenças microbianas. Uma das infecções que afetam os idosos, principalmente os imunocomprometidos, é a candidose, a qual pode ser causada por diferentes espécies de Candida, em especial Candida albicans (C. albicans). Os monócitos e macrófagos exercem funções essenciais no combate a microrganismos através do processo fagocítico que abrange a produção de espécies reativas do nitrogênio e oxigênio que culminam no controle e/ou morte do patógeno. Uma vez esses fatores comprometidos, o combate aos agentes agressores é dificultado e ou ineficaz fazendo com que estas disfunções ocasionem problemas clínicos. Sendo assim, o objetivo do presente trabalho foi avaliar in vitro a capacidade fagocítica, a geração de óxido nítrico (NO) e peróxido de hidrogênio (H2O2) intracelular, e a habilidade de controlar o crescimento extracelular do fungo C. albicans por monócitos e macrófagos humanos de idosos e jovens. Para isso, foram obtidos monócitos do sangue periférico de indivíduos idosos e jovens os quais permaneceram em cultura por 7 dias e se diferenciaram em macrófagos. Ambos os fagócitos foram desafiadas com diferentes proporções de C. albicans viáveis (5 células:1 fungo, 1:1 e 1:5) por 30min, 2h e 5h. Após os desafios, os dados foram analisados por meio de ensaio fluorescente de fagocitose e crescimento fúngico extracelular, e pelos kits DAF-FM diacetato (NO) e Cell Rox Deep (H2O2). Os resultados foram expressos como média ± desvio padrão (SD) dos valores ou porcentagens obtidos e a análise estatística foi...


Currently, the world population is undergoing a process of demographic transition, associated with a considerable increase in the number of elderly compared with young subjects. The rapid growth of the elderly population is a major concern of the modern society, which requires an increase in the study of health and improved quality of life for the aged. This includes a greater clarification of the pathophysiological aspects of microbial diseases. One of the infections affecting the elderly, particularly those immunocompromised, is the candidosis that can be caused by various Candida species, especially Candida albicans (C. albicans). Monocytes and macrophages exert essential functions in combating microorganisms by phagocytic process. During this process occur the production of reactive nitrogen species and reactive oxygen species that culminate in the control and/or death of the pathogen. Once these factors are affected, the fight against aggressors is difficult and/or ineffective, and these disorders can cause clinical problems. Thus, the aim of this in vitro study was to investigate occurrence of phagocytosis, the intracellular generation of nitric oxide (NO) and hydrogen peroxide (H2O2), and the ability of human monocytes and macrophages from young and old in controlling the extracellular growth of the fungus C. albicans. Therefore, peripheral blood monocytes from elderly and young subjects were obtained and remained in culture for 7 days until they differentiate into macrophages. Both mononuclear cells were challenged with different proportions of viable C. albicans (5 cells:1 fungus, 1:1 and 1:5) for 30min, 2h and 5h. After the challenges, it was possible to evaluate the ability of fungal internalization and the controlling of extracellular fungal growth by a fluorescent assay, and measure the intracellular production of nitric oxide (NO) by DAF-FM Diacetate and hydrogen peroxide (H2O2) by Rox Deep Cell Kit. The results were expressed as mean ± standard...


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Candida albicans/fisiologia , Macrófagos/imunologia , Macrófagos/microbiologia , Monócitos/imunologia , Monócitos/microbiologia , Fatores Etários , Análise de Variância , Sobrevivência Celular , Imunofluorescência , Fagocitose/fisiologia , Óxido Nítrico/metabolismo , Peróxido de Hidrogênio/metabolismo , Fatores de Tempo
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