C/EBPβ Promotes Immunity to Oral Candidiasis through Regulation of β-Defensins

PLoS One. 2015 Aug 28;10(8):e0136538. doi: 10.1371/journal.pone.0136538. eCollection 2015.

Abstract

Humans or mice subjected to immunosuppression, such as corticosteroids or anti-cytokine biologic therapies, are susceptible to mucosal infections by the commensal fungus Candida albicans. Recently it has become evident that the Th17/IL-17 axis is essential for immunity to candidiasis, but the downstream events that control immunity to this fungus are poorly understood. The CCAAT/Enhancer Binding Protein-β (C/EBPβ) transcription factor is important for signaling by multiple inflammatory stimuli, including IL-17. C/EBPβ is regulated in a variety of ways by IL-17, and controls several downstream IL-17 target genes. However, the role of C/EBPβ in vivo is poorly understood, in part because C/EBPβ-deficient mice are challenging to breed and work with. In this study, we sought to understand the role of C/EBPβ in the context of an IL-17-dependent immune response, using C. albicans infection as a model system. Confirming prior findings, we found that C/EBPβ is required for immunity to systemic candidiasis. In contrast, C/EBPβ(-/-) mice were resistant to oropharyngeal candidiasis (OPC), in a manner indistinguishable from immunocompetent WT mice. However, C/EBPβ(-/-) mice experienced more severe OPC than WT mice in the context of cortisone-induced immunosuppression. Expression of the antimicrobial peptide β-defensin (BD)-3 correlated strongly with susceptibility in C/EBPβ(-/-) mice, but no other IL-17-dependent genes were associated with susceptibility. Therefore, C/EBPβ contributes to immunity to mucosal candidiasis during cortisone immunosuppression in a manner linked to β-defensin 3 expression, but is apparently dispensable for the IL-17-dependent response.

Publication types

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

MeSH terms

  • Animals
  • CCAAT-Enhancer-Binding Protein-beta / genetics
  • CCAAT-Enhancer-Binding Protein-beta / immunology*
  • Candida albicans / immunology*
  • Candidiasis, Oral / genetics
  • Candidiasis, Oral / immunology*
  • Candidiasis, Oral / pathology
  • Gene Expression Regulation / immunology*
  • Interleukin-17 / genetics
  • Interleukin-17 / immunology
  • Mice
  • Mice, Knockout
  • beta-Defensins / genetics
  • beta-Defensins / immunology*

Substances

  • CCAAT-Enhancer-Binding Protein-beta
  • Cebpb protein, mouse
  • Interleukin-17
  • beta-Defensins