alexa Induction of capsule growth in Cryptococcus neoformans by mammalian serum and CO(2).
Genetics & Molecular Biology

Genetics & Molecular Biology

Fungal Genomics & Biology

Author(s): Zaragoza O, Fries BC, Casadevall A

Abstract Share this page

Abstract The pathogenic fungus Cryptococcus neoformans has a polysaccharide capsule that is essential for virulence in vivo. Capsule size is known to increase during animal infection, and this phenomenon was recently associated with virulence. Although various conditions have been implicated in promoting capsule growth, including CO(2) concentration, osmolarity, and phenotypic switching, it is difficult to reproduce the capsule enlargement effect in the laboratory. In this study, we report that serum can induce capsule growth, and we describe the conditions that induce this effect, not only by serum but also by CO(2). Capsule enlargement was dependent on the medium used, and this determined whether the strain responded to serum or CO(2) efficiently. Serum was most effective in inducing capsule growth under nutrient-limited conditions. There was considerable variability between strains in their response to either serum or CO(2), with some strains requiring both stimuli. Sera from several animal sources were each highly efficient in inducing capsule growth. The cyclic AMP (cAMP) pathway and Ras1 were both necessary for serum-induced capsule growth. The lack of induction in the ras1 mutant was not complemented by exogenous cAMP, indicating that these pathways act in parallel. However, both cAMP and Ras1 were dispensable for inducing a partial capsule growth by CO(2), suggesting that multiple pathways participate in this process. The ability of serum to induce capsule growth suggests a mechanism for the capsular enlargement observed during animal infection.
This article was published in Infect Immun and referenced in Fungal Genomics & Biology

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

  • World Congress on Mycology
    September 11-13, 2017 Los Angeles, USA
  • International Conference on Microbial Ecology
    September 18-20, 2017 Toronto, Canada
  • International Conference on Fungal Diseases & Control
    September 25-26, 2017 Dubai, UAE
  • 2nd International Conference on Mycology & Mushrooms
    September 25-26, 2017 Chicago, USA

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version