Related Experiment Video

Updated: Mar 29, 2026

Biolistic Transformation of a Fluorescent Tagged Gene into the Opportunistic Fungal Pathogen Cryptococcus neoformans
07:32

Biolistic Transformation of a Fluorescent Tagged Gene into the Opportunistic Fungal Pathogen Cryptococcus neoformans

Published on: March 19, 2015

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ALL2, a Homologue of ALL1, Has a Distinct Role in Regulating pH Homeostasis in the Pathogen Cryptococcus neoformans

Neena Jain1, Tejas Bouklas2, Anjali Gupta1

  • 1Department of Medicine (Infectious Diseases), Albert Einstein College of Medicine, Bronx, New York, USA.

Infection and Immunity
|November 25, 2015
PubMed

Insights

The study reveals that allergen 2 (ALL2) is crucial for Cryptococcus neoformans virulence, unlike allergen 1 (ALL1). Loss of ALL2 impairs the fungus's ability to maintain intracellular pH, reducing its resilience and pathogenicity.

Area of Science:

  • Mycology
  • Pathogen Biology
  • Molecular Genetics

Background:

  • Cryptococcus neoformans is a fungal pathogen causing meningoencephalitis.
  • Its capsule and acid survival are key to host resilience.
  • Previous work linked allergen 1 (ALL1) to exopolysaccharide properties and iron homeostasis.

Purpose of the Study:

  • To characterize the function of the homologous gene, allergen 2 (ALL2), in C. neoformans.
  • To investigate ALL2's role in fungal virulence and host-pathogen interactions.

Main Methods:

  • Generation of C. neoformans null mutants for ALL2 (all2Δ).
  • Assessment of virulence using a pulmonary infection model.
  • Analysis of exopolysaccharide properties, hydrogen peroxide sensitivity, and macrophage-mediated killing.
  • Transcriptome analysis to compare gene functions.

Main Results:

  • Loss of ALL2 (all2Δ) attenuated virulence in the pulmonary infection model.
  • The all2Δ mutant produced less viscous exopolysaccharide and showed increased sensitivity to hydrogen peroxide.
  • all2Δ mutants were more resistant to macrophage killing.
  • ALL2 uniquely functions in maintaining intracellular pH under low-pH conditions, distinct from ALL1's role in iron homeostasis.

Conclusions:

  • ALL2 is a distinct virulence-associated gene in C. neoformans.
  • ALL2 plays a critical role in maintaining intracellular pH, contributing to fungal resilience.
  • These findings highlight unique gene sets evolved by C. neoformans for survival in the human niche.

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