Role of Aspergillus fumigatus DvrA in host cell interactions and virulence

Eukaryot Cell. 2010 Oct;9(10):1432-40. doi: 10.1128/EC.00055-10. Epub 2010 Jul 30.

Abstract

The transcription factors that regulate Aspergillus fumigatus interactions with host cells and virulence are incompletely defined. We investigated the role of the putative C2H2 transcription factor DvrA in governing these processes. Although DvrA was identified by its limited homology to Candida albicans Bcr1, a ΔdvrA mutant strain of A. fumigatus had wild-type adherence to host constituents in vitro. However, it had increased capacity to damage both endothelial cells and a pulmonary epithelial cell line compared to the ability of the wild-type strain and a ΔdvrA::dvrA-complemented strain. This increase in damage required direct contact between the mutant and host cells. The ΔdvrA mutant also stimulated greater CCL20, interleukin-8, and tumor necrosis factor mRNA expression in a pulmonary epithelial cell line compared to levels induced by the control strains. Also, it was resistant to nikkomycin Z, suggesting an altered cell wall composition. As predicted by these in vitro results, the ΔdvrA mutant had increased virulence and stimulated a greater pulmonary inflammatory response than the wild-type strain and ΔdvrA::dvrA-complemented strains in the nonneutropenic mouse model of invasive pulmonary aspergillosis. These results indicate that DvrA influences A. fumigatus virulence as well as its capacity to damage host cells and stimulate a proinflammatory response.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aspergillus fumigatus / genetics
  • Aspergillus fumigatus / metabolism
  • Aspergillus fumigatus / pathogenicity*
  • Cell Line
  • Cells, Cultured
  • Cytokines / metabolism
  • Endothelial Cells / microbiology*
  • Endothelial Cells / pathology
  • Epithelial Cells / immunology
  • Epithelial Cells / microbiology*
  • Epithelial Cells / pathology
  • Fungal Proteins / chemistry
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism
  • Host-Pathogen Interactions*
  • Humans
  • Invasive Pulmonary Aspergillosis / microbiology
  • Invasive Pulmonary Aspergillosis / pathology
  • Lung / cytology
  • Lung / microbiology*
  • Lung / pathology
  • Mice
  • Moths / microbiology
  • Transcription Factors / chemistry
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Virulence

Substances

  • Cytokines
  • Fungal Proteins
  • Transcription Factors