Capsule of Cryptococcus neoformans grows by enlargement of polysaccharide molecules

Susana Frases, Bruno Pontes, Leonardo Nimrichter, Nathan B. Viana, Marcio L. Rodrigues, Arturo Casadevall

Research output: Contribution to journalArticle

Abstract

The human pathogenic fungus Cryptococcus neoformans has a distinctive polysaccharide (PS) capsule that enlarges during infection. The capsule is essential for virulence, but the mechanism for capsular growth is unknown. In the present study, we used dynamic light scattering (LS) analysis of capsular PS and optical tweezers (OT) to explore the architecture of the capsule. Analysis of capsular PS from cells with small and large capsules by dynamic LS revealed a linear correlation between PS effective diameter and microscopic capsular diameter. This result implied that capsule growth was achieved by the addition of molecules with larger effective diameter, such that some molecules can span the entire diameter of the capsule. Measurement of polystyrene bead penetration of C. neoformans capsules by using OT techniques revealed that the outer regions were penetrable, but not the inner regions. Our results provide a mechanism for capsular enlargement based on the axial lengthening of PS molecules and suggest a model for the architecture of a eukaryotic microbial capsule.

Original languageEnglish (US)
Pages (from-to)1228-1233
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume106
Issue number4
DOIs
StatePublished - Jan 27 2009
Externally publishedYes

Fingerprint

Cryptococcus neoformans
Capsules
Polysaccharides
Optical Tweezers
Polystyrenes
Growth
Virulence
Fungi
Infection

Keywords

  • GalXM
  • GXM

ASJC Scopus subject areas

  • General

Cite this

Capsule of Cryptococcus neoformans grows by enlargement of polysaccharide molecules. / Frases, Susana; Pontes, Bruno; Nimrichter, Leonardo; Viana, Nathan B.; Rodrigues, Marcio L.; Casadevall, Arturo.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 106, No. 4, 27.01.2009, p. 1228-1233.

Research output: Contribution to journalArticle

Frases, Susana ; Pontes, Bruno ; Nimrichter, Leonardo ; Viana, Nathan B. ; Rodrigues, Marcio L. ; Casadevall, Arturo. / Capsule of Cryptococcus neoformans grows by enlargement of polysaccharide molecules. In: Proceedings of the National Academy of Sciences of the United States of America. 2009 ; Vol. 106, No. 4. pp. 1228-1233.
@article{543dab9115a1412c934c747c9040ff53,
title = "Capsule of Cryptococcus neoformans grows by enlargement of polysaccharide molecules",
abstract = "The human pathogenic fungus Cryptococcus neoformans has a distinctive polysaccharide (PS) capsule that enlarges during infection. The capsule is essential for virulence, but the mechanism for capsular growth is unknown. In the present study, we used dynamic light scattering (LS) analysis of capsular PS and optical tweezers (OT) to explore the architecture of the capsule. Analysis of capsular PS from cells with small and large capsules by dynamic LS revealed a linear correlation between PS effective diameter and microscopic capsular diameter. This result implied that capsule growth was achieved by the addition of molecules with larger effective diameter, such that some molecules can span the entire diameter of the capsule. Measurement of polystyrene bead penetration of C. neoformans capsules by using OT techniques revealed that the outer regions were penetrable, but not the inner regions. Our results provide a mechanism for capsular enlargement based on the axial lengthening of PS molecules and suggest a model for the architecture of a eukaryotic microbial capsule.",
keywords = "GalXM, GXM",
author = "Susana Frases and Bruno Pontes and Leonardo Nimrichter and Viana, {Nathan B.} and Rodrigues, {Marcio L.} and Arturo Casadevall",
year = "2009",
month = "1",
day = "27",
doi = "10.1073/pnas.0808995106",
language = "English (US)",
volume = "106",
pages = "1228--1233",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
number = "4",

}

TY - JOUR

T1 - Capsule of Cryptococcus neoformans grows by enlargement of polysaccharide molecules

AU - Frases, Susana

AU - Pontes, Bruno

AU - Nimrichter, Leonardo

AU - Viana, Nathan B.

AU - Rodrigues, Marcio L.

AU - Casadevall, Arturo

PY - 2009/1/27

Y1 - 2009/1/27

N2 - The human pathogenic fungus Cryptococcus neoformans has a distinctive polysaccharide (PS) capsule that enlarges during infection. The capsule is essential for virulence, but the mechanism for capsular growth is unknown. In the present study, we used dynamic light scattering (LS) analysis of capsular PS and optical tweezers (OT) to explore the architecture of the capsule. Analysis of capsular PS from cells with small and large capsules by dynamic LS revealed a linear correlation between PS effective diameter and microscopic capsular diameter. This result implied that capsule growth was achieved by the addition of molecules with larger effective diameter, such that some molecules can span the entire diameter of the capsule. Measurement of polystyrene bead penetration of C. neoformans capsules by using OT techniques revealed that the outer regions were penetrable, but not the inner regions. Our results provide a mechanism for capsular enlargement based on the axial lengthening of PS molecules and suggest a model for the architecture of a eukaryotic microbial capsule.

AB - The human pathogenic fungus Cryptococcus neoformans has a distinctive polysaccharide (PS) capsule that enlarges during infection. The capsule is essential for virulence, but the mechanism for capsular growth is unknown. In the present study, we used dynamic light scattering (LS) analysis of capsular PS and optical tweezers (OT) to explore the architecture of the capsule. Analysis of capsular PS from cells with small and large capsules by dynamic LS revealed a linear correlation between PS effective diameter and microscopic capsular diameter. This result implied that capsule growth was achieved by the addition of molecules with larger effective diameter, such that some molecules can span the entire diameter of the capsule. Measurement of polystyrene bead penetration of C. neoformans capsules by using OT techniques revealed that the outer regions were penetrable, but not the inner regions. Our results provide a mechanism for capsular enlargement based on the axial lengthening of PS molecules and suggest a model for the architecture of a eukaryotic microbial capsule.

KW - GalXM

KW - GXM

UR - http://www.scopus.com/inward/record.url?scp=59049087993&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=59049087993&partnerID=8YFLogxK

U2 - 10.1073/pnas.0808995106

DO - 10.1073/pnas.0808995106

M3 - Article

VL - 106

SP - 1228

EP - 1233

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

SN - 0027-8424

IS - 4

ER -