Iron acquisition and oxidative stress response in aspergillus fumigatus

dc.contributor.authorBrandon, Madisonen
dc.contributor.authorHoward, Braden
dc.contributor.authorLawrence, Christopher B.en
dc.contributor.authorLaubenbacher, Reinhard C.en
dc.contributor.departmentBiological Sciencesen
dc.contributor.departmentFralin Life Sciences Instituteen
dc.description.abstractBackground: Aspergillus fumigatus is a ubiquitous airborne fungal pathogen that presents a life-threatening health risk to individuals with weakened immune systems. A. fumigatus pathogenicity depends on its ability to acquire iron from the host and to resist host-generated oxidative stress. Gaining a deeper understanding of the molecular mechanisms governing A. fumigatus iron acquisition and oxidative stress response may ultimately help to improve the diagnosis and treatment of invasive aspergillus infections. Results: This study follows a systems biology approach to investigate how adaptive behaviors emerge from molecular interactions underlying A. fumigatus iron regulation and oxidative stress response. We construct a Boolean network model from known interactions and simulate how changes in environmental iron and superoxide levels affect network dynamics. We propose rules for linking long term model behavior to qualitative estimates of cell growth and cell death. These rules are used to predict phenotypes of gene deletion strains. The model is validated on the basis of its ability to reproduce literature data not used in model generation. Conclusions: The model reproduces gene expression patterns in experimental time course data when A. fumigatus is switched from a low iron to a high iron environment. In addition, the model is able to accurately represent the phenotypes of many knockout strains under varying iron and superoxide conditions. Model simulations support the hypothesis that intracellular iron regulates A. fumigatus transcription factors, SreA and HapX, by a post-translational, rather than transcriptional, mechanism. Finally, the model predicts that blocking siderophore-mediated iron uptake reduces resistance to oxidative stress. This indicates that combined targeting of siderophore-mediated iron uptake and the oxidative stress response network may act synergistically to increase fungal cell killing.en
dc.description.sponsorshipThis work was supported in part by NIH/NIAID grant number 1R21AI101619 to RL and CL.en
dc.format.extent18 pagesen
dc.identifier.citationBrandon et al. BMC Systems Biology (2015) 9:19 DOI 10.1186/s12918-015-0163-1en
dc.rightsCreative Commons Attribution 4.0 Internationalen
dc.subjectBoolean networken
dc.subjectDiscrete dynamic modelen
dc.subjectInvasive aspergillosisen
dc.subjectStochastic discrete dynamical systemen
dc.titleIron acquisition and oxidative stress response in aspergillus fumigatusen
dc.title.serialBMC Evolutionary Biologyen
dc.typeArticle - Refereeden


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