SciELO - Scientific Electronic Library Online

 
vol.15 issue1Immediate radical fang mark ablation may allow treatment of japanese viper bite without antivenomModulatory effects of tuberculosis vaccines on experimental autoimmune encephalomyelitis author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Journal

Article

Indicators

Related links

Share


Journal of Venomous Animals and Toxins including Tropical Diseases

On-line version ISSN 1678-9199

J. Venom. Anim. Toxins incl. Trop. Dis vol.15 no.1 Botucatu  2009

http://dx.doi.org/10.1590/S1678-91992009000100017 

THESIS

 

Production of prostaglandins and leukotrienes by Paracoccidioides brasiliensis

 

 

Correspondence to

 

 

Thesis: G. A. Biondo submitted this thesis for his Masters in Tropical Diseases at the Botucatu Medical School, São Paulo State University, UNESP, Botucatu, São Paulo State, Brazil, 2008.

Advisor: Professor Angela Maria Victoriano de Campos Soares

Paracoccidioides brasiliensis is the causative agent of paracoccidioidomycosis, the most prevalent deep mycosis in Latin America. Production of eicosanoids, including prostaglandins and leukotrienes, during fungal infections is theorized to play a critical role on fungal survival and/or growth as well as on host immune response modulation. Host cells are one source of these mediators; however another potential source may be the fungus itself. The purpose of our study was to assess whether P. brasiliensis strains with different degree of virulence (Pb18, Pb265, PbBT79, Pb192) produce both, prostaglandin E2 (PGE2) and leukotriene B4 (LTB4). Moreover, we asked if P. brasiliensis can use exogenous sources of  arachidonic acid (AA), as well as metabolic pathways dependent on  cyclooxygenase (COX)  and lipoxygenase (5-LO ) enzymes, for PGE2 and LTB4 production, respectively. Finally, a possible association between these eicosanoids and fungus viability was assessed. We demonstrated, using ELISA assays, that all P. brasiliensis strains, independently of their virulence, produce high PGE2 and LTB4 levels after a 4-hour culture, which were reduced after 8 hours. However, in both culture times, higher eicosanoids levels were detected when culture medium was supplemented with exogenous AA. Differently, treatment with indomethacin, a COX inhibitor, or MK886, a 5-LO inhibitor, induces a reduction on PGE2 and LTB4 levels, respectively, as well as in fungus viability. The data provide evidence that P. brasiliensis is able to metabolize either endogenous or exogenous AA by pathways that depend on COX and 5-LO enzymes for producing, respectively, PGE2 and LTB4 that are critical for its viability.

Key words: arachidonic acid, eicosanoids, leukotrienes, Paracoccidioides brasiliensis, prostaglandin.

 

 

Correspondence to:
Guilherme Augusto Biondo
Departamento de Doenças Tropicais
Faculdade de Medicina de Botucatu, UNESP
Botucatu, SP, 18618-000, Brasil
Phone: +55 14 3882-6022
Email: guibiondo@yahoo.com.br.

Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License