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Fungal Genet Biol DOI:10.1016/j.fgb.2017.01.005

Paracoccidioides spp. catalases and their role in antioxidant defense against host defense responses.

Publication TypeJournal Article
Year of Publication2017
AuthorsTamayo, D, Muñoz, JF, Almeida, AJ, Puerta, JD, Restrepo, Á, Cuomo, CA, McEwen, JG, Hernández, O
JournalFungal Genet Biol
Volume100
Pages22-32
Date Published2017 Mar
ISSN1096-0937
Abstract

Dimorphic human pathogenic fungi interact with host effector cells resisting their microbicidal mechanisms. Yeast cells are able of surviving within the tough environment of the phagolysosome by expressing an antioxidant defense system that provides protection against host-derived reactive oxygen species (ROS). This includes the production of catalases (CATs). Here we identified and analyzed the role of CAT isoforms in Paracoccidioides, the etiological agent of paracoccidioidomycosis. Firstly, we found that one of these isoforms was absent in the closely related dimorphic pathogen Coccidioides and dermatophytes, but all of them were conserved in Paracoccidioides, Histoplasma and Blastomyces species. We probed the contribution of CATs in Paracoccidioides by determining the gene expression levels of each isoform through quantitative RT-qPCR, in both the yeast and mycelia phases, and during the morphological switch (transition and germination), as well as in response to oxidative agents and during interaction with neutrophils. PbCATP was preferentially expressed in the pathogenic yeast phase, and was associated to the response against exogenous H2O2. Therefore, we created and analyzed the virulence defects of a knockdown strain for this isoform, and found that CATP protects yeast cells from H2O2 generated in vitro and is relevant during lung infection. On the other hand, CATA and CATB seem to contribute to ROS homeostasis in Paracoccidioides cells, during endogenous oxidative stress. CAT isoforms in Paracoccidioides might be coordinately regulated during development and dimorphism, and differentially expressed in response to different stresses to control ROS homeostasis during the infectious process, contributing to the virulence of Paracoccidioides.

DOI10.1016/j.fgb.2017.01.005
Pubmed

http://www.ncbi.nlm.nih.gov/pubmed/28093309?dopt=Abstract

Alternate JournalFungal Genet. Biol.
PubMed ID28093309
Grant ListU19 AI110818 / AI / NIAID NIH HHS / United States