Reducing Aspergillus fumigatus Virulence through Targeted Dysregulation of the Conidiation Pathway
James I. P. Stewart, Vinicius M. Fava, Joshua D. Kerkaert, Adithya S. Subramanian, Fabrice N. Gravelat, Mélanie Lehoux, P. Lynne Howell, Robert A. Cramer, Donald C. Sheppard
Abstract
The mold Aspergillus fumigatus reproduces by the production of airborne spores (conidia), a process termed conidiation. In immunocompromised individuals, inhaled A. fumigatus conidia can germinate and form filaments that penetrate and damage lung tissues; however, conidiation does not occur during invasive infection. In this study, we demonstrate that forced activation of conidiation in filaments of A. fumigatus can arrest their growth and impair the ability of this fungus to cause disease in both an insect and a mouse model of invasive infection. Activation of conidiation was linked to profound changes in A. fumigatus metabolism, including a shift away from the synthesis of polysaccharides required for cell wall structure and virulence in favor of carbohydrates used for energy storage and stress resistance. Collectively, these findings suggest that activation of the conidiation pathway may be a promising approach for the development of new agents to prevent or treat A. fumigatus infection.