Please use this identifier to cite or link to this item: https://www.arca.fiocruz.br/handle/icict/7437
Title: Leishmania (L.) amazonensis-induced inhibition of nitric oxide synthesis in host macrophages
Authors: Balestieri, Filomena Maria Perrella
Queiroz, Allan R. Pires
Scavone, Cristoforo
Costa, Vlaudia M. Assis
Barral Netto, Manoel
Abrahamsohn, Ises de Almeida
Affilliation: Universidade Federal da Paraíba. Departamento de Fisiologia e Patologia. Laboratório de Tecnologia Farmacêutica. João Pessoa, PB, Brasil
Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Faculdade de Medicina. Salvador, BA, Brasil
Universidade de São Paulo. ICB. Departamento de Farmacologia. Cidade Universitária. São Paulo, SP, Brasil
Universidade de São Paulo. ICB. Departamento de Imunologia. Cidade Universitária. São Paulo, SP, Brasil
Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Faculdade de Medicina. Salvador, BA, Brasil
Universidade de São Paulo. ICB. Departamento de Imunologia. Cidade Universitária. São Paulo, SP, Brasil
Abstract: Inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) production was demonstrated in J774-G8 macrophages infected with Leishmania (L.) amazonensis promastigotes. The downmodulation of NO production observed in infected and LPS-stimulated J774-G8 cells correlated with a reduction in inducible nitric oxide synthase (iNOS) activity. Reduction in iNOS activity was not paralleled by decreased iNOS mRNA expression, suggesting that the parasite affects post-transcriptional events of NO synthesis. Supplementation with L-arginine or tetrahydrobiopterin did not increase NO production, suggesting that inhibition is not due to an insufficiency of substrate or co-factor. Treatment with anti-IL-10, anti-IL-4 or anti-TGF-beta neutralizing antibodies also failed to increase NO production, indicating that these cytokines are not involved in the observed parasite-induced inhibition of NO synthesis. However, treatment of the cultures with IFN-gamma resulted in a marked increase in NO production by infected LPS-stimulated cells. These results show that although L.(L.) amazonensis infection inhibits iNOS activity and NO production by J774-G8 cells, activation by IFN-gamma is capable of overriding the suppression of NO synthesis.
Keywords: Leishmania (L.) amazonensis
Macrophage
Nitric oxide
INOS activity
INOS mRNA
IFN-γ
Animais
Células Cultivadas
DeCS: Leishmania/patogenicidade
Leishmaniose/parasitologia
Macrófagos/parasitologia
Óxido Nítrico/biossíntese
Lipopolissacarídeos/farmacologia
Macrófagos/efeitos de drogas
Macrófagos/metabolismo
Camundongos
Óxido Nítrico Sintase/genética
Óxido Nítrico Sintase/metabolismo
Óxido Nítrico Sintase Tipo II
RNA Mensageiro/genética
RNA Mensageiro/metabolismo
Issue Date: 2002
Publisher: Elsevier SAS
Citation: BALESTIERI, F. et al. Leishmania (L.) amazonensis-induced inhibition of nitric oxide synthesis in host macrophages. Microbes and Infection, v. 4, p. 23-29, 2002.
ISSN: 1286-4579
Copyright: open access
Appears in Collections:BA - IGM - Artigos de Periódicos

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