Aspergillus niger α-1,3-glucan acts as a virulence factor by inhibiting the insect phenoloxidase system

J Invertebr Pathol. 2020 Mar:171:107341. doi: 10.1016/j.jip.2020.107341. Epub 2020 Feb 10.

Abstract

Phenoloxidase (PO) is a key enzyme in the melanization process involved in elimination of pathogens in insects. The PO system is rapidly activated in response to pathogen recognition. Inhibition of PO activity can be a way to avoid immune response and increase infection effectiveness. In this study, the effects of inoculation of Galleria mellonella larvae with Aspergillus niger α-1,3-glucan and conidia on PO activity in hemolymph are analyzed in comparison with the effects of β-1,3/1,6-glucan inoculation. Our results indicate that α-1,3-glucan, a fungal cell wall polysaccharide, can play a role of a virulence factor involved in inhibition of the insect PO system.

Keywords: Aspergillus niger; Galleria mellonella; Host-pathogen interaction; Innate immunity; Phenoloxidase; Virulence factor; α-1,3-Glucan.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aspergillus niger / physiology*
  • Glucans / physiology*
  • Insect Proteins / antagonists & inhibitors*
  • Larva / growth & development
  • Larva / microbiology
  • Monophenol Monooxygenase / antagonists & inhibitors*
  • Moths / growth & development
  • Moths / microbiology*
  • Spores, Fungal / physiology
  • Virulence Factors / physiology*

Substances

  • Glucans
  • Insect Proteins
  • Virulence Factors
  • alpha-1,3-glucan
  • Monophenol Monooxygenase