Candida Infection Biology – fungal armoury, battlefields ... - FINSysB

Iff2 is a cell surface protein involved in adhesion
Iaroslava Kos 1 , Grégory Da Costa 1 , Céline Monniot 1 , Anita Boisramé 1
Marie-Noëlle Bellon Fontaine 2 , Murielle Chauvel 3 , Christophe d’Enfert 3 and
Mathias L. Richard 1
1 Team “Virulence and Fungal Infection” Institut Micalis, UMR1319 INRA AgroParisTech,
78850 Thiverval-Grignon, FRANCE; 2 Team “Bioadhésion et Hygiène des Matériaux” Institut
Micalis, UMR1319 INRA AgroParisTech, 91744 Massy, FRANCE; 3 Team “Fungal Biology and
Pathogenicity”, Pasteur Institute, 75015 Paris, FRANCE.
In Candida albicans, the cell wall and especially cell wall proteins are known to play
a key role in the relationship between the fungal cell, the host and most indwelling
device, contributing to adhesion, immune response modulation and deep seated
infections. A specific class of cell wall proteins has been particularly under the
scope in the past decade: the glycosylphosphatidylinositol anchored proteins
(GpiPs). The largest family of GpiPs is a family of 12 proteins sharing a high similarity
with Hyr1. One of its members, Iff2 has been the subject of a large scale study in
our laboratory in order to decipher his putative function in C. albicans. The cell
localization of Iff2 was assessed using a V5-tagged protein and clearly showed that
Iff2 is a cell surface protein tethered to the cell wall proteins through alkali-Pir-like
links as well as di-sulfide bonds. We also demonstrated that Iff2 protrude from the
cell wall glucan network at the interface with the cellular environment. At the gene
level, we showed that IFF2 is a gene with an expression level stronger than most of
the member of Hyr/Iff family in laboratory conditions and that IFF2 is induced during
the stationary phase in the same media. An overexpressing strain with IFF2 under
the control of TEF1p was hyper adherent to different plastic but not to silicon,
resulting in the formation of stronger biofilm at the early stage of biofilm formation
compared to the reference strain. The future work is aimed to understand which
part of the protein is important for adhesion and if it is specific to Iff2 functional
domain. Additional experiments are also planned to monitor the consequences of
this overexpression in in vitro and in vivo models.
We are grateful to the European Commission for funding the FINSysB Marie Curie Initial Training Network
(PITN-GA-2008-214004).
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