Paracoccidioides lutzii Infects Galleria mellonella Employing Formamidase as a Virulence Factor

PLoS Negl Trop Dis. 2024 Sep 3;18(9):e0012452. doi: 10.1371/journal.pntd.0012452. eCollection 2024 Sep.

Abstract

The formamidase (FMD) enzyme plays an important role in fungal thriving by releasing a secondary nitrogen source as a product of its activity. In Paracoccidioides species, previous studies have demonstrated the upregulation of this enzyme in a wide range of starvation and infective-like conditions. However, Paracoccidioides lutzii formamidase has not yet been defined as a virulence factor. Here, by employing in vivo infections using an fmd-silenced strain in Galleria mellonella larvae model, we demonstrate the influence of formamidase in P. lutzii's immune stimulation and pathogenicity. The formamidase silencing resulted in improper arrangement of the nodules, poor melanogenesis and decreased fungal burden. Thus, we suggest that formamidase may be a piece composing the process of molecular recognition by Galleria immune cells. Furthermore, formamidase silencing doubled the observed survival rate of the larvae, demonstrating its importance in fungal virulence in vivo. Therefore, our findings indicate that formamidase contributes to Galleria's immune incitement and establishes the role of this enzyme as a P. lutzii virulence factor.

MeSH terms

  • Animals
  • Disease Models, Animal
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism
  • Gene Silencing
  • Larva* / microbiology
  • Moths* / microbiology
  • Paracoccidioides* / enzymology
  • Paracoccidioides* / genetics
  • Paracoccidioides* / pathogenicity
  • Paracoccidioidomycosis / microbiology
  • Virulence
  • Virulence Factors* / genetics
  • Virulence Factors* / metabolism

Substances

  • Virulence Factors
  • Fungal Proteins

Grants and funding

This work was majorly financed by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) through CLB grant number 408042/2021-4. At the basal level, the techniques performed were also supported by Fundação de Amparo à Pesquisa do Estado de Goiás (FAPEG), Instituto Nacional de Ciência e Tecnologia (INCT-IPH-FAPEG),; grant number INCT-IPH-FAPEG 201810267000022 to CMAS. CLB has a fellowship from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq- 308237/2022-6). EDP, TRM and JAM receive salary from Coordenação de Aperfeiçoamento de Pessoal Nível Superior (CAPES). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.