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Phenotypic variation and intracellular parasitism by histoplasma Capsulatum

S Kügler1, T Schurtz Sebghati, L Groppe Eissenberg

  • 1Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA.

Proceedings of the National Academy of Sciences of the United States of America
|August 2, 2000
PubMed

Insights

Histoplasma capsulatum needs to change from mold to yeast to infect hosts. This study explores how yeast-specific alpha-(1,3)-glucan and a calcium-binding protein aid its survival within macrophages.

Area of Science:

  • Mycology
  • Infectious Diseases
  • Cell Biology

Background:

  • Histoplasma capsulatum is an intracellular pathogen requiring a morphological transition from mycelial to yeast form for virulence.
  • Yeast phase-specific factors are crucial for H. capsulatum survival and proliferation within host macrophages.

Purpose of the Study:

  • To investigate the role and regulation of alpha-(1,3)-glucan, a cell wall polysaccharide modulated by quorum sensing.
  • To examine the function of a secreted calcium-binding protein (CBP) essential for H. capsulatum pathogenicity.

Main Methods:

  • Analysis of yeast-specific characteristics in H. capsulatum.
  • Investigating the regulation of alpha-(1,3)-glucan by cell-density sensing.
  • Assessing the role of a secreted calcium-binding protein in fungal pathogenesis.

Main Results:

  • Identified alpha-(1,3)-glucan as a yeast-specific cell wall component regulated by quorum sensing.
  • Demonstrated the essential role of a secreted calcium-binding protein (CBP) in H. capsulatum pathogenicity.
  • Highlighted the importance of these yeast-specific factors for intracellular survival.

Conclusions:

  • Alpha-(1,3)-glucan and the secreted CBP are key virulence factors for Histoplasma capsulatum.
  • Understanding these yeast-specific elements provides insights into fungal pathogenesis.
  • Targeting these factors could offer new strategies for treating histoplasmosis.

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