Engineered Fluorescent Strains of Cryptococcus neoformans : a Versatile Toolbox for Studies of Host-Pathogen Interactions and Fungal Biology, Including the Viable but Nonculturable State

Cryptococcus neoformans is an opportunistic fungal pathogen known for its remarkable ability to infect and subvert phagocytes. This ability provides survival and persistence within the host and relies on phenotypic plasticity. The viable but nonculturable (VBNC) phenotype was recently described in C. neoformans, whose study is promising in understanding the pathophysiology of cryptococcosis. The use of fluorescent strains is improving host interaction research, but it is still underexploited. Here, we fused histone H3 or the poly(A) binding protein (Pab) to enhanced green fluorescent protein (eGFP) or mCherry, obtaining a set of C. neoformans transformants with different colors, patterns of fluorescence, and selective markers (hygromycin B resistance [Hygr] or neomycin resistance [Neor]). We validated their similarity to the parental strain in the stress response, the expression of virulence-related phenotypes, mating, virulence in Galleria mellonella, and survival within murine macrophages. PAB-GFP, the brightest transformant, was successfully applied for the analysis of phagocytosis by flow cytometry and fluorescence microscopy. Moreover, we demonstrated that an engineered fluorescent strain of C. neoformans was able to generate VBNC cells. GFP-tagged Pab1, a key regulator of the stress response, evidenced nuclear retention of Pab1 and the assembly of cytoplasmic stress granules, unveiling posttranscriptional mechanisms associated with dormant C. neoformans cells. Our results support that the PAB-GFP strain is a useful tool for research on C. neoformans. IMPORTANCE Cryptococcus neoformans is a human-pathogenic yeast that can undergo a dormant state and is responsible for over 180,000 deaths annually worldwide. We engineered a set of fluorescent transformants to aid in research on C. neoformans. A mutant with GFP-tagged Pab1 improved fluorescence-based techniques used in host interaction studies. Moreover, this mutant induced a viable but nonculturable phenotype and uncovered posttranscriptional mechanisms associated with dormant C. neoformans. The experimental use of fluorescent mutants may shed light on C. neoformans-host interactions and fungal biology, including dormant phenotypes.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:10

Enthalten in:

Microbiology spectrum - 10(2022), 5 vom: 26. Okt., Seite e0150422

Sprache:

Englisch

Beteiligte Personen:

de Castro, Raffael Júnio Araújo [VerfasserIn]
Rêgo, Marco Túlio Aidar Mariano [VerfasserIn]
Brandão, Fabiana S [VerfasserIn]
Pérez, Ana Laura Alfonso [VerfasserIn]
De Marco, Janice Lisboa [VerfasserIn]
Poças-Fonseca, Marcio José [VerfasserIn]
Nichols, Connie [VerfasserIn]
Alspaugh, J Andrew [VerfasserIn]
Felipe, Maria Sueli S [VerfasserIn]
Alanio, Alexandre [VerfasserIn]
Bocca, Anamélia Lorenzetti [VerfasserIn]
Fernandes, Larissa [VerfasserIn]

Links:

Volltext

Themen:

3XQ2233B0B
Cryptococcus neoformans
Dormancy
Fluorescently tagged strains
GFP
H99
Histone H3
Histones
Hygromycin B
I16QD7X297
Journal Article
MCherry
Neomycin
Poly(A) binding protein
Research Support, Non-U.S. Gov't
Stress granules
VBNC

Anmerkungen:

Date Completed 28.10.2022

Date Revised 20.10.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1128/spectrum.01504-22

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM345238842