scholarly journals Mannan molecular sub-structures control nanoscale glucan exposure in Candida

2017 ◽  
Author(s):  
Matthew S. Graus ◽  
Michael J. Wester ◽  
Douglas W. Lowman ◽  
David L. Williams ◽  
Michael D. Kruppa ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Super Resolution ◽  
Ligand Interaction ◽  
Interaction Sites ◽  
Single Receptor ◽  
Labile N ◽  
Innate Immune Evasion ◽  
Acid Labile

AbstractN-linked mannans (N-mannans) in the cell wall of Candida albicans are thought to mask β-(1,3)-glucan from recognition by Dectin-1, contributing to innate immune evasion. Lateral cell wall exposures of glucan on Candida albicans are predominantly single receptor-ligand interaction sites and are restricted to nanoscale geometries. Candida species exhibit a range of basal glucan exposures and their mannans also vary in size and complexity at the molecular level. We used super resolution fluorescence imaging and a series of protein mannosylation mutants in C. albicans and C. glabrata to investigate the role of specific N-mannan features in regulating the nanoscale geometry of glucan exposure. Decreasing acid labile mannan abundance and α-(1,6)-mannan backbone length correlated most strongly with increased density and nanoscopic size of glucan exposures in C. albicans and C. glabrata, respectively. Additionally, a C. albicans clinical isolate with high glucan exposure produced similarly perturbed N-mannan structures and exhibited similar changes to nanoscopic glucan exposure geometry. We conclude that acid labile N-mannan controls glucan exposure geometry at the nanoscale. Furthermore, variations in glucan nanoexposure characteristics are clinically relevant and are likely to impact the nature of the pathogenic surface presented to innate immunocytes at dimensions relevant to receptor engagement, aggregation and signaling.

scholarly journals Role of the Candida albicans MNN1 gene family in cell wall structure and virulence

2013 ◽  
Vol 6 (1) ◽  
Author(s):  
Steven Bates ◽  
Rebecca A Hall ◽  
Jill Cheetham ◽  
Mihai G Netea ◽  
Donna M MacCallum ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Gene Family ◽  
Cell Wall Structure ◽  
Wall Structure

The role of TNF-α in a murine model of Kawasaki disease arteritis induced with a Candida albicans cell wall polysaccharide

2013 ◽  
Vol 24 (1) ◽  
pp. 120-128 ◽  
Author(s):  
Toshiaki Oharaseki ◽  
Yuki Yokouchi ◽  
Hitomi Yamada ◽  
Hiroshi Mamada ◽  
Satoshi Muto ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Kawasaki Disease ◽  
Murine Model ◽  
Cell Wall Polysaccharide ◽  
Tnf Α

scholarly journals Role of Transcription Factor CaNdt80p in Cell Separation, Hyphal Growth, and Virulence in Candida albicans

2010 ◽  
Vol 9 (4) ◽  
pp. 634-644 ◽  
Author(s):  
Adnane Sellam ◽  
Christopher Askew ◽  
Elias Epp ◽  
Faiza Tebbji ◽  
Alaka Mullick ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Candida Albicans ◽  
Cell Separation ◽  
Hyphal Growth ◽  
Functional Domain ◽  
Transcription Factor Family ◽  
Content Type ◽  
Genes Encoding

ABSTRACT The NDT80/PhoG transcription factor family includes ScNdt80p, a key modulator of the progression of meiotic division in Saccharomyces cerevisiae. In Candida albicans, a member of this family, CaNdt80p, modulates azole sensitivity by controlling the expression of ergosterol biosynthesis genes. We previously demonstrated that CaNdt80p promoter targets, in addition to ERG genes, were significantly enriched in genes related to hyphal growth. Here, we report that CaNdt80p is indeed required for hyphal growth in response to different filament-inducing cues and for the proper expression of genes characterizing the filamentous transcriptional program. These include noteworthy genes encoding cell wall components, such as HWP1, ECE1, RBT4, and ALS3. We also show that CaNdt80p is essential for the completion of cell separation through the direct transcriptional regulation of genes encoding the chitinase Cht3p and the cell wall glucosidase Sun41p. Consistent with their hyphal defect, ndt80 mutants are avirulent in a mouse model of systemic candidiasis. Interestingly, based on functional-domain organization, CaNdt80p seems to be a unique regulator characterizing fungi from the CTG clade within the subphylum Saccharomycotina. Therefore, this study revealed a new role of the novel member of the fungal NDT80 transcription factor family as a regulator of cell separation, hyphal growth, and virulence.

The role of TNF-α in a murine model of Kawasaki disease arteritis induced with a Candida albicans cell wall polysaccharide

2013 ◽  
Author(s):  
Toshiaki Oharaseki ◽  
Yuki Yokouchi ◽  
Hitomi Yamada ◽  
Hiroshi Mamada ◽  
Satoshi Muto ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Kawasaki Disease ◽  
Murine Model ◽  
Cell Wall Polysaccharide ◽  
Tnf Α

scholarly journals Cooperative Role of MAPK Pathways in the Interaction of Candida albicans with the Host Epithelium

2019 ◽  
Vol 8 (1) ◽  
pp. 48 ◽  
Author(s):  
Inês Correia ◽  
Daniel Prieto ◽  
Elvira Román ◽  
Duncan Wilson ◽  
Bernhard Hube ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Epithelial Damage ◽  
Mapk Pathways ◽  
Molecular Approaches ◽  
Abiotic Surfaces ◽  
Solid Media ◽  
Epithelial Invasion ◽  
Semi Solid

Candida albicans is an important human fungal pathogen responsible for tens of millions of infections as well as hundreds of thousands of severe life-threatening infections each year. MAP kinase (MAPK) signal transduction pathways facilitate the sensing and adaptation to external stimuli and control the expression of key virulence factors such as the yeast-to-hypha transition, the biogenesis of the cell wall, and the interaction with the host. In the present study, we have combined molecular approaches and infection biology to analyse the role of C. albicans MAPK pathways during an epithelial invasion. Hog1 was found to be important for adhesion to abiotic surfaces but was dispensable for damage to epithelial cells. The Mkc1 cell wall integrity (CWI) and Cek1 pathways, on the other hand, were both required for oral epithelial damage. Analysis of the ability to penetrate nutrient-rich semi-solid media revealed a cooperative role for Cek1 and Mkc1 in this process. Finally, cek2Δ (as well as cek1Δ) but not mkc1Δ or hog1Δ mutants, exhibited elevated β-glucan unmasking as revealed by immunofluorescence studies. Therefore, the four MAPK pathways play distinct roles in adhesion, epithelial damage, invasion and cell wall remodelling that may contribute to the pathogenicity of C. albicans.

scholarly journals Cell Wall Mannan and Cell Surface Hydrophobicity in Candida albicans Serotype A and B Strains

2004 ◽  
Vol 72 (11) ◽  
pp. 6230-6236 ◽  
Author(s):  
James Masuoka ◽  
Kevin C. Hazen
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Cell Surface ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Stable Region ◽  
Common Mechanism ◽  
Composition Analysis ◽  
Acid Stable ◽  
Acid Labile

ABSTRACT Cell surface hydrophobicity contributes to the pathogenesis of the opportunistic fungal pathogen Candida albicans. Previous work demonstrated a correlation between hydrophobicity status and changes in the acid-labile, phosphodiester-linked β-1,2-oligomannoside components of the N-linked glycans of cell wall mannoprotein. Glycan composition also defines the two major serotypes, A and B, of C. albicans strains. Here, we show that the cell surface hydrophobicity of the two serotypes is qualitatively different, suggesting that the serotypes may differ in how they modulate cell surface hydrophobicity status. The cell wall mannoproteins from hydrophilic and hydrophobic cells of both serotypes were compared to determine whether the glycan differences due to serotype affect the glycan differences due to hydrophobicity status. Composition analysis showed that the protein, hexose, and phosphate contents of the mannoprotein fraction did not differ significantly among the strains tested. Electrophoretic profiles of the acid-labile mannan differed only with hydrophobicity status, not serotype, though some strain-specific differences were observed. Furthermore, a newly available β-1,2-oligomannoside ladder allowed unambiguous identification of acid-labile mannan components. Finally, to assess whether the acid-stable mannan also affects cell surface hydrophobicity status, this fraction was fragmented into its component branches by acetolysis. The electrophoretic profiles of the acid-stable branches were very similar regardless of hydrophobicity status. However, differences were observed between serotypes. These results support and extend our current model that modification of the acid-labile β-1,2-oligomannoside chain length but not modification of the acid-stable region is one common mechanism by which switching of cell surface hydrophobicity status of C. albicans strains occurs.

scholarly journals Candida albicans cell wall integrity transcription factors regulate polymicrobial biofilm formation with Streptococcus gordonii

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7870 ◽  
Author(s):  
Jennifer Chinnici ◽  
Lisa Yerke ◽  
Charlene Tsou ◽  
Sujay Busarajan ◽  
Ryan Mancuso ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Transcription Factors ◽  
Biofilm Formation ◽  
Mixed Cultures ◽  
Cell Wall Integrity ◽  
Antibiotic Tolerance ◽  
Streptococcus Gordonii ◽  
Knock Out

Polymicrobial biofilms play important roles in oral and systemic infections. The oral plaque bacterium Streptococcus gordonii is known to attach to the hyphal cell wall of the fungus Candida albicans to form corn-cob like structures in biofilms. However, the role of C. albicans in formation of polymicrobial biofilms is not completely understood. The objective of this study was to determine the role of C. albicans transcription factors in regulation of polymicrobial biofilms and antibiotic tolerance of S. gordonii. The proteins secreted by C. albicans and S. gordonii in mixed planktonic cultures were determined using mass spectrometry. Antibiotic tolerance of S. gordonii to ampicillin and erythromycin was determined in mixed cultures and mixed biofilms with C. albicans. Additionally, biofilm formation of S. gordonii with C. albicans knock-out mutants of 45 transcription factors that affect cell wall integrity, filamentous growth and biofilm formation was determined. Furthermore, these mutants were also screened for antibiotic tolerance in mixed biofilms with S. gordonii. Analysis of secreted proteomes resulted in the identification of proteins being secreted exclusively in mixed cultures. Antibiotic testing showed that S. gordonii had significantly increased survival in mixed planktonic cultures with antibiotics as compared to single cultures. C. albicans mutants of transcription factors Sfl2, Brg1, Leu3, Cas5, Cta4, Tec1, Tup1, Rim101 and Efg1 were significantly affected in mixed biofilm formation. Also mixed biofilms of S. gordonii with mutants of C. albicans transcription factors, Tec1 and Sfl2, had significantly reduced antibiotic tolerance as compared to control cultures. Our data indicates that C. albicans may have an important role in mixed biofilm formation as well as antibiotic tolerance of S. gordonii in polymicrobial biofilms. C. albicans may play a facilitating role than being just an innocent bystander in oral biofilms and infections.

scholarly journals Role of Pir1 in the construction of the Candida albicans cell wall

Microbiology ◽  
2004 ◽  
Vol 150 (10) ◽  
pp. 3151-3161 ◽  
Author(s):  
A. I. Martinez
Keyword(s):  
Cell Wall ◽  
Candida Albicans

scholarly journals Characterizing the Role of Cell-Wall β-1,3-Exoglucanase Xog1p in Candida albicans Adhesion by the Human Antimicrobial Peptide LL-37

PLoS ONE ◽  
2011 ◽  
Vol 6 (6) ◽  
pp. e21394 ◽  
Author(s):  
Pei-Wen Tsai ◽  
Cheng-Yao Yang ◽  
Hao-Teng Chang ◽  
Chung-Yu Lan
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Antimicrobial Peptide

scholarly journals Attenuation of the Activity of Caspofungin at High Concentrations against Candida albicans: Possible Role of Cell Wall Integrity and Calcineurin Pathways

2005 ◽  
Vol 49 (12) ◽  
pp. 5146-5148 ◽  
Author(s):  
Nathan P. Wiederhold ◽  
Dimitrios P. Kontoyiannis ◽  
Randall A. Prince ◽  
Russell E. Lewis
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Deletion Mutant ◽  
Cell Wall Integrity ◽  
Short Exposure ◽  
Wild Type ◽  
High Concentrations

ABSTRACT Caspofungin had diminished activity in vitro against Candida albicans at concentrations of 8 to 32 μg/ml. This phenomenon was markedly attenuated in a Δmkc1/Δmkc1 deletion mutant and by the addition of cyclosporine to the wild type. Short exposure to these caspofungin concentrations resulted in MKC1 up-regulation, suggesting roles of cell wall integrity and calcineurin pathways.

Sign in / Sign up

Export Citation Format

Share Document