IL-1 Coordinates the Neutrophil Response to C. albicans in the Oral Mucosa

PLoS Pathog. 2016 Sep 15;12(9):e1005882. doi: 10.1371/journal.ppat.1005882. eCollection 2016 Sep.

Abstract

Mucosal infections with Candida albicans belong to the most frequent forms of fungal diseases. Host protection is conferred by cellular immunity; however, the induction of antifungal immunity is not well understood. Using a mouse model of oropharyngeal candidiasis (OPC) we show that interleukin-1 receptor (IL-1R) signaling is critical for fungal control at the onset of infection through its impact on neutrophils at two levels. We demonstrate that both the recruitment of circulating neutrophils to the site of infection and the mobilization of newly generated neutrophils from the bone marrow depended on IL-1R. Consistently, IL-1R-deficient mice displayed impaired chemokine production at the site of infection and defective secretion of granulocyte colony-stimulating factor (G-CSF) in the circulation in response to C. albicans. Strikingly, endothelial cells were identified as the primary cellular source of G-CSF during OPC, which responded to IL-1α that was released from keratinocytes in the infected tissue. The IL-1-dependent crosstalk between two different cellular subsets of the nonhematopoietic compartment was confirmed in vitro using a novel murine tongue-derived keratinocyte cell line and an established endothelial cell line. These data establish a new link between IL-1 and granulopoiesis in the context of fungal infection. Together, we identified two complementary mechanisms coordinating the neutrophil response in the oral mucosa, which is critical for preventing fungal growth and dissemination, and thus protects the host from disease.

MeSH terms

  • Animals
  • Candida albicans / immunology*
  • Candidiasis / genetics
  • Candidiasis / immunology*
  • Endothelial Cells / immunology
  • Endothelial Cells / microbiology
  • Granulocyte Colony-Stimulating Factor / genetics
  • Granulocyte Colony-Stimulating Factor / immunology
  • Interleukin-1alpha / genetics
  • Interleukin-1alpha / immunology*
  • Keratinocytes / immunology
  • Keratinocytes / microbiology
  • Mice
  • Mice, Knockout
  • Mouth Mucosa / immunology*
  • Mouth Mucosa / microbiology
  • Myelopoiesis / genetics
  • Myelopoiesis / immunology
  • Neutrophils / immunology*
  • Receptors, Interleukin-1 / genetics
  • Receptors, Interleukin-1 / immunology
  • Tongue / immunology
  • Tongue / microbiology

Substances

  • Interleukin-1alpha
  • Receptors, Interleukin-1
  • Granulocyte Colony-Stimulating Factor

Grants and funding

The LeibundGut-lab was supported by funding from the Swiss National Science Foundation (grants CRSII3_141848 and PP00P3_150758 to SLL; www.snf.ch). Florian Sparber is a recipient of an Erwin Schrödinger Fellowship from the Austrian Science Fund. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.