Original Article
Multiparametric imaging of adhesive nanodomains at the surface of Candida albicans by atomic force microscopy

https://doi.org/10.1016/j.nano.2014.07.008Get rights and content

Abstract

Candida albicans is an opportunistic pathogen. It adheres to mammalian cells through a variety of adhesins that interact with host ligands. The spatial organization of these adhesins on the cellular interface is however poorly understood, mainly because of the lack of an instrument able to track single molecules on single cells. In this context, the atomic force microscope (AFM) makes it possible to analyze the force signature of single proteins on single cells. The present study is dedicated to the mapping of the adhesive properties of C. albicans cells. We observed that the adhesins at the cell surface were organized in nanodomains composed of free or aggregated mannoproteins. This was demonstrated by the use of functionalized AFM tips and synthetic amyloid forming/disrupting peptides. This direct visualization of amyloids nanodomains will help in understanding the virulence factors of C. albicans.

From the Clinical Editor

The present study reports on the successful atomic force microscopy-based mapping of the adhesive properties of C. albicans cells, an accomplishment that highlights the utility of AFM.

Section snippets

Yeasts growth conditions

Candida albicans (from ABC Platform® Bugs Bank, Nancy, France) was stocked at − 80 °C, revivified on Yeast Peptone Dextrose agar (Difco, 242720-500g) and grown in Yeast Peptone Dextrose broth (Difco, 242820-500g) for 20 hours at 30 °C under static conditions.

Sample preparation for AFM experiments

Yeast cells were concentrated by centrifugation, washed two times in acetate buffer (18 mM CH3COONa, 1 mM CaCl2, 1 mM MnCl2, pH = 5.2), resuspended in acetate buffer, and immobilized on polydimethylsiloxane (PDMS) stamps prepared as described by

Candida albicans cells display localized adhesiveness

Thanks to our innovative method to immobilize cells into PDMS stamps,18 and using Quantitative Imaging™ mode,16 we were able to image and quantify the adhesive properties of single C. albicans cells at the same time. Figure 1, A, shows a budding yeast cell; on the corresponding adhesion image (Figure 1, B), we can see that only the bud, and not the mother-cell, presents adhesives patches. This original result is surprising as non-budding cells are highly adhesive (see below). This result seems

Discussion

We show in this study that wild-type live C. albicans cells exhibit extraordinary adhesive properties. In the case of budding cells, placed in acetate buffer at 25 °C for 2 hours, we observed that the mother cell is not adhesive and that only the bud presents adhesive nanodomains. On the contrary, we show that non budding cells are covered by adhesive nanodomains, in the same experimental conditions. This illustrates the amazing plasticity of this species2, 27 able to grow as a commensal or as a

References (37)

  • P.S. Dannies

    Concentrating hormones into secretory granules: Layers of control

    Mol Cell Endocrinol

    (2001)
  • D. Poulain

    Candida albicans, plasticity and pathogenesis

    Crit Rev Microbiol

    (2013)
  • L.L. Hoyer et al.

    Discovering the secrets of the Candida albicans agglutinin-like sequence (ALS) gene family – a sticky pursuit

    Med Mycol

    (2008)
  • C.B. Ramsook et al.

    Yeast cell adhesion molecules have functional amyloid-forming sequences

    Eukaryot Cell

    (2010)
  • M.R. Sawaya et al.

    Atomic structures of amyloid cross-β spines reveal varied steric zippers

    Nature

    (2007)
  • M.C. Garcia et al.

    A role for amyloid in cell aggregation and biofilm formation

    PLoS ONE

    (2011)
  • J.M. Rauceo et al.

    Global cell surface conformational shift mediated by a candida albicans adhesin

    Infect Immun

    (2004)
  • D. Alsteens et al.

    Atomic force microscopy: a new look at pathogens

    PLoS Pathog

    (2013)
  • Cited by (41)

    • Toxic effects of SiO<inf>2</inf>NPs in early embryogenesis of Xenopus laevis

      2022, Chemosphere
      Citation Excerpt :

      SiO2 is the most abundant compound in the Earth's crust and could, in the form of nanoparticles, bioaccumulate in the environment and along the food chain with possible hazardous effects (Napierska et al., 2010). Among various types of nanoparticles, the silica nanoparticles (SiO2NPs), are considered stable and non-toxic and are favored as nanostructuring, drug delivery, and optical imaging agents (Formosa et al., 2015; Saint-Cricq et al., 2015; Sonin et al., 2016). They are also applied in the remediation of the environment pollutants (see Jeelani et al., 2020), used as an additive for the manufacturing of rubber and plastics, as strengthening filler for concrete and other construction composites, as anti-caking agent to maintain flow properties in powdered products and as a carrier for fragrances or flavors in food and nonfood products (Robberecht et al., 2008; Dekkers et al., 2011; Martirosyan and Schneider, 2014).

    • Atomic force microscopy to elucidate how peptides disrupt membranes

      2021, Biochimica et Biophysica Acta - Biomembranes
    • The importance of force in microbial cell adhesion

      2020, Current Opinion in Colloid and Interface Science
    • Microbial adhesion and ultrastructure from the single-molecule to the single-cell levels by Atomic Force Microscopy

      2019, Cell Surface
      Citation Excerpt :

      This allows the cell to increase local adhesion strength during either cell-substrate or cell-cell interactions (Alsteens et al., 2010). The presence of such adhesins clusters has also been observed in living C. albicans depending on the budding stage of the cells (Formosa et al., 2015b). Adhesive patches have been reported as well at the surface of a specific strain of S. cerevisiae, and attributed – via completementary transcriptomic analyses- to the flocculin proteins FLO11 (Schiavone et al., 2015).

    • Single-molecule atomic force microscopy studies of microbial pathogens

      2019, Current Opinion in Biomedical Engineering
      Citation Excerpt :

      Together with SCFS data, these results pointed to a complex role of zinc in SasG-mediated adhesion: adsorption of zinc ions to cell wall components increases the cohesion of the cell surface, thus promoting the extension of SasG proteins beyond other surface components and making them fully available for zinc-dependent homophilic interactions. The adhesion forces of S. aureus onto human corneocytes were mapped, revealing the occurrence of specific interactions between pathogen adhesins and target ligands well spread on corneocytes [53]. Finally, amyloid nanodomains were mapped on C. albicans cells and found to exhibit different adhesiveness related to their stiffness and hydrophobic state [21].

    View all citing articles on Scopus

    This work was supported by an ANR young scientist program (AFMYST project ANR-11-JSV5-001-01 n°SD 30024331) to ED. CF and MS are respectively supported by a grant from “Direction Générale de l’Armement” (DGA) and from Lallemand SAS. ED is a researcher at Centre National de la Recherche Scientifique. We are grateful to “Association Lorraine pour la Recherche et le Développement de Composés Bioactifs”, for its financial support.

    View full text