Remasking of Candida albicans β-Glucan in response to environmental pH is regulated by quorum sensing

Research output: Contribution to journalArticlepeer-review

Authors

  • Sarah Sherrington
  • Sarah Cockerill
  • Valentina del Olmo Toledo
  • Stephen Kissane
  • Helene Tournu
  • Glen Palmer
  • J. Christian Perez

Colleges, School and Institutes

External organisations

  • University of Birmingham
  • University of Wuerzburg
  • University of Tennessee, Knoxville
  • University of Wurzburg

Abstract

Candida albicans is a commensal yeast of the human gut which is tolerated by the immune system but has the potential to become an opportunistic pathogen. One way in which C. albicans achieves this duality is through concealing or exposing cell wall pathogen-associated molecular patterns (PAMPs) in response to hostderived environment cues (pH, hypoxia, and lactate). This cell wall remodeling allows C. albicans to evade or hyperactivate the host’s innate immune responses, leading to disease. Previously, we showed that adaptation of C. albicans to acidic environments, conditions encountered during colonization of the female reproductive tract, induces significant cell wall remodeling resulting in the exposure of two key fungal PAMPs (-glucan and chitin). Here, we report that this pH-dependent cell wall remodeling is time dependent, with the initial change in pH driving cell wall unmasking, which is then remasked at later time points. Remasking of -glucan was mediated via the cell density-dependent fungal quorum sensing molecule farnesol, while chitin remasking was mediated via a small, heat-stable, nonproteinaceous secreted molecule(s). Transcript profiling identified a core set of 42 genes significantly regulated by pH over time and identified the transcription factor Efg1 as a regulator of chitin exposure through regulation of CHT2. This dynamic cell wall remodeling influenced innate immune recognition of C. albicans, suggesting that during infection, C. albicans can manipulate the host innate immune responses.

Details

Original languageEnglish
Article numbere02347-19
JournalmBio
Volume10
Issue number5
Publication statusPublished - 15 Oct 2019

Keywords

  • Candida albicans, cell wall, chitin, glucans, pH sensing, quorum sensing

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