Use este identificador para citar ou linkar para este item: http://ri.ufs.br/jspui/handle/riufs/932
Tipo de Documento: Artigo
Título: Resistance of Leishmania (Viannia) braziliensis to nitric oxide: correlation with antimony therapy and TNF-α production
Autor(es): Souza, Anselmo
Giudice, Ângela
Pereira, Júlia M. B.
Guimarães, Luiz Henrique Santos
Jesus, Amélia Maria Ribeiro de
Moura, Tatiana Rodrigues de
Wilson, Mary
Carvalho Filho, Edgar Marcelino de
Almeida, Roque Pacheco de
Data do documento: Jul-2010
Abstract: BACKGROUND: Nitric oxide (NO) produced in macrophages plays a pivotal role as a leishmanicidal agent. A previous study has demonstrated that 20% of the L. (V.) braziliensis isolated from initial cutaneous lesions of patients from the endemic area of Corte de Pedra, Bahia, Brazil, were NO resistant. Additionally, 5 to 11% of the patients did not respond to three or more antimony treatments" (refractory patients). The aim of this study is to investigate if there is an association between the resistance of L. (V.) braziliensis to NO and nonresponsiveness to antimony therapy and cytokine production. METHODS: We evaluated the in vitro toxicity of NO against the promastigotes stages of L. (V.) braziliensis isolated from responsive and refractory patients, and the infectivity of the amastigote forms of these isolates against human macrophages. The supernatants from Leishmania infected macrophage were used to measure TNF-α and IL-10 levels. RESULTS: Using NaNO2 (pH 5.0) as the NO source, L. (V.) braziliensis isolated from refractory patients were more NO resistant (IC50 = 5.8 ± 4.8) than L. (V.) braziliensis isolated from responsive patients (IC50 = 2.0 ± 1.4). Four isolates were selected to infect human macrophages: NO-susceptible and NO-resistant L. (V.) braziliensis isolated from responsive and refractory patients. NO-resistant L. (V.) braziliensis isolated from refractory patients infected more macrophages stimulated with LPS and IFN-γ at 120 hours than NO-susceptible L. (V.) braziliensis isolated from refractory patients. Also, lower levels of TNF-α were detected in supernatants of macrophages infected with NO-resistant L. (V.) braziliensis as compared to macrophages infected with NO-susceptible L. (V.) braziliensis (p < 0.05 at 2, 24 and 120 hours), while no differences were detected in IL-10 levels. CONCLUSION: These data suggest that NO resistance could be related to the nonresponsiveness to antimony therapy seen in American Tegumentary Leishmaniasis.
Palavras-chave: Leishmania
Leishmania braziliensis
Leishmaniose
TNF-α
Antimônio
ISSN: 1471-2334
Instituição/Editora: BioMed Central
Citação: SOUZA, A. Resistance of Leishmania (Viannia) braziliensis to nitric oxide: correlation with antimony therapy and TNF-α production. BMC Infectious Diseases, v. 10, n. 209, jul. 2010. Disponível em: <http://www.biomedcentral.com/1471-2334/10/209>. Acesso em: 21 fev. 2014.
Licença: Creative Commons Attribution License
URI: https://ri.ufs.br/handle/riufs/932
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