Host iron withholding demands siderophore utilization for Candida glabrata to survive macrophage killing.

Published

Journal Article

The fungal pathogen Candida glabrata has risen from an innocuous commensal to a major human pathogen that causes life-threatening infections with an associated mortality rate of up to 50%. The dramatic rise in the number of immunocompromised individuals from HIV infection, tuberculosis, and as a result of immunosuppressive regimens in cancer treatment and transplant interventions have created a new and hitherto unchartered niche for the proliferation of C. glabrata. Iron acquisition is a known microbial virulence determinant and human diseases of iron overload have been found to correlate with increased bacterial burden. Given that more than 2 billion people worldwide suffer from iron deficiency and that iron overload is one of the most common single-gene inherited diseases, it is important to understand whether host iron status may influence C. glabrata infectious disease progression. Here we identify Sit1 as the sole siderophore-iron transporter in C. glabrata and demonstrate that siderophore-mediated iron acquisition is critical for enhancing C. glabrata survival to the microbicidal activities of macrophages. Within the Sit1 transporter, we identify a conserved extracellular SIderophore Transporter Domain (SITD) that is critical for siderophore-mediated ability of C. glabrata to resist macrophage killing. Using macrophage models of human iron overload disease, we demonstrate that C. glabrata senses altered iron levels within the phagosomal compartment. Moreover, Sit1 functions as a determinant for C. glabrata to survive macrophage killing in a manner that is dependent on macrophage iron status. These studies suggest that host iron status is a modifier of infectious disease that modulates the dependence on distinct mechanisms of microbial Fe acquisition.

Full Text

Duke Authors

Cited Authors

  • Nevitt, T; Thiele, DJ

Published Date

  • March 2011

Published In

Volume / Issue

  • 7 / 3

Start / End Page

  • e1001322 -

PubMed ID

  • 21445236

Pubmed Central ID

  • 21445236

Electronic International Standard Serial Number (EISSN)

  • 1553-7374

Digital Object Identifier (DOI)

  • 10.1371/journal.ppat.1001322

Language

  • eng

Conference Location

  • United States