Please use this identifier to cite or link to this item:
https://repositorio.ufba.br/handle/ri/7600
metadata.dc.type: | Artigo de Periódico |
Title: | Leishmania (L.) amazonensis-induced inhibition of nitric oxide synthesis in host macrophages |
Other Titles: | Microbes and Infection |
Authors: | Balestieri, Filomena Maria Perrella Queiroz, Allan Rêgo Pires Scavone, Cristoforo Costa, Vlaudia Maria Assis Barral-Netto, Manoel Abrahamsohn, Ises de Almeida |
metadata.dc.creator: | Balestieri, Filomena Maria Perrella Queiroz, Allan Rêgo Pires Scavone, Cristoforo Costa, Vlaudia Maria Assis Barral-Netto, Manoel Abrahamsohn, Ises de Almeida |
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-β 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-γ 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-γ is capable of overriding the suppression of NO synthesis. |
Keywords: | Leishmania (L.) amazonensis Macrophage Nitric oxide iNOS activity iNOS mRNA IFN-γ |
URI: | http://www.repositorio.ufba.br/ri/handle/ri/7600 |
Issue Date: | 2002 |
Appears in Collections: | Artigo Publicado em Periódico (Faculdade de Medicina) |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
1-s2.0-S1286457901015052-main.pdf Restricted Access | 136,24 kB | Adobe PDF | View/Open Request a copy |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.