Efeito da interleucina-15 sobre a atividade fungicida, metabolismo oxidativo e produção de citocinas por monócitos humanos, infectados in vitro com Paracoccidioides brasiliensis
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Data
2007-02-15
Autores
Castro, Camila Ferreira Bannwart [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A interleucina-15 (IL-15) é uma citocina pró-inflamatória produzida principalmente por monócitos e macrófagos em resposta a agentes infecciosos, desempenhando importante papel modulador na imunidade inata e adaptativa. O objetivo do presente trabalho foi avaliar o efeito da IL-15 sobre a atividade fungicida, metabolismo oxidativo e a produção de citocinas por monócitos humanos, infectados in vitro com cepa virulenta de Paracoccidioides brasiliensis (Pb18). Monócitos de sangue periférico, obtidos de indivíduos saudáveis, foram préincubados na ausência ou presença de IL-15 (12,5, 25 e 50 ng/mL) por 24 h a 37oC e infectados com Pb18 na proporção de 50 monócitos para uma célula fúngica durante 4 h e 18 h. A atividade fungicida de monócitos foi determinada após 4 h pela recuperação de fungos viáveis por plaqueamento das co-culturas em meio BHI-ágar. O metabolismo oxidativo foi avaliado pela liberação de peróxido de hidrogênio (H2O2) e de ânion superóxido (O2 -) nas culturas desafiadas com Pb18 e estimuladas com phorbol myristate acetate (PMA) durante 60 mim. A produção de fator de necrose tumoral-alfa (TNF-a), IL-6, IL-10 e IL-15 foi determinada por ensaio imunoenzimático (ELISA) nos sobrenadantes das coculturas obtidos após 4 e 18 h de incubação. Os resultados mostraram que a préincubação de monócitos com IL-15 induziu aumento significativo na atividade fungicida contra Pb18 de maneira dose-dependente, sendo esse efeito neutralizado pela adição de anticorpo monoclonal anti-IL-15. O tratamento com IL- 15 não interferiu na capacidade de liberação de H2O2 e O2 - por monócitos desafiados com Pb18 sugerindo que a atividade fungicida estimulada por IL-15 ocorre por mecanismos independentes do metabolismo oxidativo. Monócitos infectados com o fungo, na ausência de IL-15, produziram níveis de TNF-a, IL-6 e IL-10...
Interleukin-15 (IL-15) is a pro-inflammatory cytokine especially produced by monocytes and macrophages against infectious agents and that play a pivotal role in teh innatte and adaptive immune response. The aim of this study was to analyze the effects of IL-15 on fungicidal activity, oxidative metabolism and cytokine production by human monocytes challenged in vitro with a virulente strain of Paracoccidioides brasiliensis (Pb18). Peripheral blood monocytes obtained from healthy individuals were pre-incubated for 24h with or without human recombinant IL-15 (12.5,25 and 50 ng/mL), and then challenged with Pb18 in a ratio of 50:1 monocytes:fungi. Fungicidal activity of monocytes against Pb18 was assessed by viable fungi recovery from 4 h co-cultures after plating in BHI-agar. Oxidative metabolism was evaluated by hydrogen peroxide (H2O2) and superoxide anion (O2 -) release in the monocyte cultures challenged by Pb18 and stimulated with phorbol myristate acetate (PMA) for 60 min. Tumor necrosis factor-alpha (TNF-a), IL-6, IL-10 and IL-15 production by monocytes were determined in culture supernatants by enzyme immunoassay (ELISA). The results showed that IL-15 ehanced fungicidal activity against Pb18 in a dose-dependent pattern. This effect was abrogated by additon of anti-IL-15 monoclonal antibody to the co-cultures. No significant effect of IL-15 on H2O2 and O2 - release by monocytes was observed suggesting that the fungicidal activity was independent of oxidative metabolism activation. Monocytes infected with P. brasiliensis in the absence of IL-15, produced significantly higher levels of TNF-a, IL-6 and IL-10 after 18 h of coculture in comparison to experiments of 4h-incubation with the fungus. The pretreatment of monocytes with IL-15 induced significant higher levels of TNF-a, IL-10 and IL-15 production by these cells challenged with the fungus... (Complete abstract click eletronic address below)
Interleukin-15 (IL-15) is a pro-inflammatory cytokine especially produced by monocytes and macrophages against infectious agents and that play a pivotal role in teh innatte and adaptive immune response. The aim of this study was to analyze the effects of IL-15 on fungicidal activity, oxidative metabolism and cytokine production by human monocytes challenged in vitro with a virulente strain of Paracoccidioides brasiliensis (Pb18). Peripheral blood monocytes obtained from healthy individuals were pre-incubated for 24h with or without human recombinant IL-15 (12.5,25 and 50 ng/mL), and then challenged with Pb18 in a ratio of 50:1 monocytes:fungi. Fungicidal activity of monocytes against Pb18 was assessed by viable fungi recovery from 4 h co-cultures after plating in BHI-agar. Oxidative metabolism was evaluated by hydrogen peroxide (H2O2) and superoxide anion (O2 -) release in the monocyte cultures challenged by Pb18 and stimulated with phorbol myristate acetate (PMA) for 60 min. Tumor necrosis factor-alpha (TNF-a), IL-6, IL-10 and IL-15 production by monocytes were determined in culture supernatants by enzyme immunoassay (ELISA). The results showed that IL-15 ehanced fungicidal activity against Pb18 in a dose-dependent pattern. This effect was abrogated by additon of anti-IL-15 monoclonal antibody to the co-cultures. No significant effect of IL-15 on H2O2 and O2 - release by monocytes was observed suggesting that the fungicidal activity was independent of oxidative metabolism activation. Monocytes infected with P. brasiliensis in the absence of IL-15, produced significantly higher levels of TNF-a, IL-6 and IL-10 after 18 h of coculture in comparison to experiments of 4h-incubation with the fungus. The pretreatment of monocytes with IL-15 induced significant higher levels of TNF-a, IL-10 and IL-15 production by these cells challenged with the fungus... (Complete abstract click eletronic address below)
Descrição
Palavras-chave
Paracoccidioides brasiliensis, Interleucina-15, Interleukin-15
Como citar
CASTRO, Camila Ferreira Bannwart. Efeito da interleucina-15 sobre a atividade fungicida, metabolismo oxidativo e produção de citocinas por monócitos humanos, infectados in vitro com Paracoccidioides brasiliensis. 2007. 69 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Medicina de Botucatu, 2007.