Reducing Aspergillus fumigatus virulence through targeted dysregulation of the conidiation pathway

Inhalation of conidia of the opportunistic mold Aspergillus fumigatus by immunocompromised hosts can lead to invasive pulmonary disease. Inhaled conidia that escape immune defenses germinate to form filamentous hyphae that invade lung tissues. Conidiation rarely occurs during invasive infection of the human host, allowing the bulk of fungal energy to be directed towards vegetative growth. We hypothesized that forced induction of conidiation during infection can suppress A. fumigatus vegetative growth, impairing the ability of this organism to cause disease. To study the effects of conidiation pathway dysregulation on A. fumigatus virulence, a key transcriptional regulator of conidiation (brlA) was expressed under the control of a doxycycline-inducible promoter. Time- and dose-dependent brlA overexpression was observed in response to doxycycline both in vitro and in vivo. Exposure of the inducible brlA overexpression strain to low doses of doxycycline under vegetative growth conditions in vitro induced conidiation, while high doses arrested growth. Overexpression of brlA attenuated A. fumigatus virulence in both an invertebrate and mouse model of invasive aspergillosis. RNA sequencing studies and phenotypic analysis revealed that brlA-overexpression results in altered cell signaling, amino acid and carbohydrate metabolism, including a marked up-regulation of trehalose biosynthesis and a downregulation in the biosynthesis of the polysaccharide virulence factor galactosaminogalactan. This proof-of-concept study demonstrates that activation of the conidiation pathway in A. fumigatus can reduce virulence and suggests that brlA-inducing small molecules may hold promise as a new class of therapeutics for A. fumigatus infection. Overall design: Examining the gene expression profiles of two A. fumigatus strains (Wild type parent and an inducible gene-overexpression mutant), in two conditions (absence and presence of the inducer molecule doxycycline), each in biological triplicate.

Identifier
Source https://data.blue-cloud.org/search-details?step=~0126CA1EDBBB843D3B17F9A3AD0B28E5772F2AE7C6F
Metadata Access https://data.blue-cloud.org/api/collections/6CA1EDBBB843D3B17F9A3AD0B28E5772F2AE7C6F
Provenance
Instrument Illumina HiSeq 4000; ILLUMINA
Publisher Blue-Cloud Data Discovery & Access service; ELIXIR-ENA
Contributor MUHC Research Institute - IDIGH, Microbiology and Immunology, McGill University
Publication Year 2024
OpenAccess true
Contact blue-cloud-support(at)maris.nl
Representation
Discipline Marine Science
Temporal Point 2020-01-16T00:00:00Z