Fungal melanin suppresses airway epithelial chemokine secretion through blockade of calcium fluxing

Nat Commun. 2024 Jul 10;15(1):5817. doi: 10.1038/s41467-024-50100-x.

Abstract

Respiratory infections caused by the human fungal pathogen Aspergillus fumigatus are a major cause of mortality for immunocompromised patients. Exposure to these pathogens occurs through inhalation, although the role of the respiratory epithelium in disease pathogenesis has not been fully defined. Employing a primary human airway epithelial model, we demonstrate that fungal melanins potently block the post-translational secretion of the chemokines CXCL1 and CXCL8 independent of transcription or the requirement of melanin to be phagocytosed, leading to a significant reduction in neutrophil recruitment to the apical airway both in vitro and in vivo. Aspergillus-derived melanin, a major constituent of the fungal cell wall, dampened airway epithelial chemokine secretion in response to fungi, bacteria, and exogenous cytokines. Furthermore, melanin muted pathogen-mediated calcium fluxing and hindered actin filamentation. Taken together, our results reveal a critical role for melanin interaction with airway epithelium in shaping the host response to fungal and bacterial pathogens.

MeSH terms

  • Animals
  • Aspergillus fumigatus*
  • Calcium* / metabolism
  • Chemokine CXCL1* / metabolism
  • Chemokines / metabolism
  • Epithelial Cells / metabolism
  • Epithelial Cells / microbiology
  • Humans
  • Interleukin-8* / metabolism
  • Melanins* / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Respiratory Mucosa / metabolism
  • Respiratory Mucosa / microbiology

Substances

  • Melanins
  • Interleukin-8
  • Calcium
  • Chemokine CXCL1
  • CXCL8 protein, human
  • CXCL1 protein, human
  • Chemokines