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Dominique Sanglard Lab

Dominique Sanglard, PhD, Associate Professor
++41 (0)21 314 4083
++41 (0)79 556 2691
dominique.sanglard@chuv.ch

Research topics (D. Sanglard)

Molecular mechanisms of antifungal drug resistance in yeast pathogens
Infections caused by fungal pathogens are common in patients with defects in their immune system. For example, patients with acquired immuno-deficiency syndrome (AIDS) can suffer from oropharyngeal candidiasis (OPC) and others undergoing organ transplantation or anti-cancer drug treatments can be affected by fungal invasive diseases. The major yeast species involved in these diseases belong to Candida albicans but also to other Candida species such as C. glabrata or C. tropicalis. Azole antifungals, especially fluconazole, have been used widely to treat theses fungal diseases. However, an increasing number of cases of clinical resistance against this antifungal correlating with in vitro resistance has been reported. The goal of our research is to investigate the mechanisms of resistance to azole antifungal agents at the molecular level in clinical yeast isolates acquiring azole resistance. Mutations in the target of azoles (ERG11) and upregulation of multidrug transporters genes were found as major madiators of azole resistance.

Regulation of multidrug transporters in Candida species
We found that ABC (ATP binding Cassette) transporters CDR1/CDR2 and the Major Facilitator MDR1 were mediators of azole resistance in C. albicans. The genes encoding these proteins are upregulated in azole-resistant strains. Regulatory cis-acting regions in the promoter of these genes have been identified. A trans-acting regulatory factor, TAC1, has been isolated as regulator of the C. albicans ABC transporter genes CDR1 and CDR2. Mutations in TAC1 confer hyperactivity to Tac1p and therefore upregulation of CDR1/CDR2 and azole resistance. In C. glabrata, PDR1 is a transcription factor controlling the expression of the ABC transporters CgCDR1, CgCDR2, and CgSNQ2 that are upregulated in azole-resistant isolates. PDR1 mutations have been identified and are responsible for hyperactivity of this transcription factor.  The mutations identified in the genes encoding these transcription factors will help to design tools for the diagnosis of antifungal resistance among yeast pathogens.

Molecular mechanisms of antifungal drug tolerance in Candida albicans
Current antifungals for the treatment of C. albicans infections in humans are mainly belonging to the class of azole antifungals and, among those, fluconazole is extensively used. C. albicans is tolerant to fluconazole (fluconazole has only fungistatic activity in C. albicans) and resistance to this agent (the decrease of drug susceptibility) can occur in clinical isolates by different mechanisms. We found that the combination of the immuno-suppressive drug cyclosporin A with fluconazole was rendering fluconazole fungicidal therefore making C. abicans not tolerant to fluconazole.. We are interested to investigate the molecular basis of this interaction. Cyclosporin A binds to cyclophilin A and this complex inhibits the activity of calcineurin, a protein phosphatase activated by a calcium signaling pathway. We found that calcineurin was essential for fluconazole tolerance in C. albicans. The exact mechanisms by which fluconazole is becoming fungicidal in the calcineurin mutant remain to be established. To answer this question, identification of calcineurin targets in C,albicans  has been initiated in our laboratory. We found a transcription factor, CRZ1, as major target of calcineurin in C. albicans, This gene being not essential for azole tolerance, other calcineurin targets are being identified.

Impact of antifungal drug resistance on virulence and fitness of fungal pathogens
Antifungal drug resistance develops by several mechanisms, however one of the common mechanism is based on altered transcriptional activities. Both in Candida albicans and Candida glabrata, mutations in transcriptional activators including TAC1, MRR1, UPC2 (C. albicans) and CgPDR1 (C. glabrata) are responsible for enhanced expression of target genes crucial for resistance, including multidrug transporters and targets of antifungal agents.
It has been recognized in several pathogens that antimicrobial resistance is associated with decreased virulence or altered fitness during infections. This dogma was addressed with azole-resistant isolates from C. glabrata in animal models of infection and surprisingly, these isolates showed enhanced virulence and fitness as compared to wild type parent isolates. Our current investigations interrogate the molecular basis of this unexpected phenotype in the perspective of host-pathogen interactions. Our experimental approaches include genome-wide transcriptional methods, in vivo assays and mammalian culture based assays.
Moreover, the effect of drug resistance development on C. albicans fitness and virulence is also addressed with fungal cells engineered to contain specific mutations in the transcriptional activators TAC1, MRR1 and UPC2.

Research topics (A. Coste)

Alix Coste, PhD, Research associate
++41 (0)21-314 4061
alix.coste@chuv.ch

Virulence factors in pathogenic fungi

Candida albicans is an opportunistic pathogen causing oral, vaginal or systemic infections in immuno-compromized patients. Such patients, like HIV+, transplanted patients and those receiving chemotherapy, are in constant augmentation. In up to 30% of the patients with C. albicans systemic infections, the issue is fatal. Control of C. albicans infections is essentially achieved using treatments inhibiting microbial growth, such as treatment with azoles. For HIV+ and transplanted patients, long-time prophylactic and therapeutic antifungal treatment are needed. C. albicans exposed for a long time to these antifungals adapts to this stress, and develops resistance leading to treatment failure. Therefore, alternative treatment strategies are needed.
Host-pathogen interaction is a key component of any infectious process. Treatment modifying this relationship can be designed. Transcription factors (TF) are potentially important for C. albicans virulence since they integrate several signals from host environment and participate in an adapted microbial response.
In this project, we develop an original approach to analyze a collection of C. albicans transcription factor mutant strains in vivo. A collection of TF mutant strains are screened in a mice model of systemic infection in order to identify those factors crucial for virulence. Additional analysis is performed on the selected TF to understand at which steps of the infection they are involved and which element of the host defense they target.
Genes under the control of those TF will then be identified in order to determine which metabolic pathways of the fungus are involved in the infection.
This analysis is important for C. albicans infection but will constitute a model for other pathogenic fungi. A mid-term outcome of this project will be a better understanding of the global host-fungus interactions, which may lead to the development of new drugs and treatment strategies.
This project is supported by the Maria Heim-Vögtlin program of the FRNS and by the Novartis Foundation for biological and medical research.

Current lab members
Name Position Contact
Alix Coste Research associate   alix.coste@chuv.ch
Françoise Ischer Technician francoise.ischer@chuv.ch
Luis Vale Silva PhD, post-doc luis-andre.vale-silva@chuv.ch
Stéphane Dorsaz PhD, post-doc stephane.dorsaz@chuv.ch
Julien Bouillon PhD student julien.bouillon@chuv.ch
Sara Vaz PhD student sara.martins-amorim-vaz@chuv.ch

Currently funded research topics

1. Novel genome-wide transcriptomic approaches to challenge Candida albicans-hosts interactions.
FNRS, Sinergia project N° CRSII3_141848.
Involved personnel: Alix Coste, research associate, and Sara Vaz, PHD student.

2. Identification of factors associated with antifungal resistance and fitness/virulence in pathogenic Candida species.
FNRS, project N° 31003A_146936.
Involved personnel: Luis Vale Silva, PHD, post-doc.

3. Identification of novel modes of action of plant natural products targeting fungal human and phytopathogens.
FNRS project N° CR23I3:143733
Involved personnel: Stéphane Dorsaz, PHD, post-doc.

 

Full publication lists

Publications 2012 D. Sanglard 255 Ko

Publications 2014 A. Coste 432 Ko

Selected publications


2013

1: Eddouzi J, Hofstetter V, Groenewald M, Manai M, Sanglard D.
    Characterization of a new clinical yeast species, Candida tunisiensis sp. nov., isolated from a strain collection from Tunisian hospitals
J Clin Microbiol. 2013 Jan;51(1):31-9. doi: 10.1128/JCM.01627-12.
2: Eddouzi J, Parker JE, Vale-Silva LA, Coste A, Ischer F, Kelly S, Manai M, Sanglard D.
    Molecular mechanisms of drug resistance in clinical Candida species isolated from tunisian hospitals.
Antimicrob Agents Chemother. 2013 Jul;57(7):3182-93. doi: 10.1128/AAC.00555-13.
3: Lohberger A, Coste A, Sanglard D.
    Distinct roles of the drug resistance transcription factors TAC1, MRR1 and UPC2 from Candida albicans in virulence.
Eukaryot Cell. 2013 Nov 15.
4: Marttila E, Bowyer P, Sanglard D, Uittamo J, Kaihovaara P, Salaspuro M, Richardson M, Rautemaa R.
    Fermentative 2-carbon metabolism produces carcinogenic levels of acetaldehyde in Candida albicans.
Mol Oral Microbiol. 2013 Jan 19. doi: 10.1111/omi.12024.
5: Silva LV, Sanguinetti M, Vandeputte P, Torelli R, Rochat B, Sanglard D
    Milbemycins: more than efflux inhibitors for fungal pathogens.
Antimicrob Agents Chemother. 2013 Feb;57(2):873-86. doi: 10.1128/AAC.02040-12.
6: Vale-Silva L, Ischer F, Leibundgut-Landmann S, Sanglard D.
    Gain-of-function mutations in PDR1, a regulator of antifungal drug resistance in Candida glabrata, control adherence to host cells.
Infect Immun. 2013 May;81(5):1709-20. doi: 10.1128/IAI.00074-13.

2012

1: Cottier F, Raymond M, Kurzai O, Bolstad M, Leewattanapasuk W, Jiménez-López C, Lorenz MC, Sanglard D, Váchová L, Pavelka N, Palková Z, Mühlschlegel FA.
    The bZIP transcription factor Rca1p is a central regulator of a novel CO₂ sensing pathway in yeast.
PLoS Pathog. 2012 Jan;8(1):e1002485. doi: 10.1371/journal.ppat.1002485.
2: Dhamgaye S, Devaux F, Manoharlal R, Vandeputte P, Shah AH, Singh A, Blugeon C, Sanglard D, Prasad R.
    In vitro effect of malachite green on Candida albicans involves multiple pathways and transcriptional regulators UPC2 and STP2.
Antimicrob Agents Chemother. 2012 Jan;56(1):495-506. doi: 10.1128/AAC.00574-11.
3: Rubino I, Coste A, Le Roy D, Roger T, Jaton K, Boeckh M, Monod M, Latgé JP, Calandra T, Bochud PY.
    Species-specific recognition of Aspergillus fumigatus by Toll-like receptor 1 and Toll-like receptor 6.
J Infect Dis. 2012 Mar 15;205(6):944-54. doi: 10.1093/infdis/jir882.
4: Vale-Silva LA, Coste AT, Ischer F, Parker JE, Kelly SL, Pinto E, Sanglard D.
    Azole resistance by loss of function of the sterol Δ⁵,⁶-desaturase gene (ERG3) in Candida albicans does not necessarily decrease virulence.
Antimicrob Agents Chemother. 2012 Apr;56(4):1960-8. doi: 10.1128/AAC.05720-11.
5: Vandeputte P, Ferrari S, Coste AT.
    Antifungal resistance and new strategies to control fungal infections.
Int J Microbiol. 2012;2012:713687.
6: Vandeputte P, Pradervand S, Ischer F, Coste AT, Ferrari S, Harshman K, Sanglard D.
    Identification and functional characterization of Rca1, a transcription factor involved in both antifungal susceptibility and host response in Candida albicans.
Eukaryot Cell. 2012 Jul;11(7):916-31. doi: 10.1128/EC.00134-12.
7: Zelante T, Iannitti RG, De Luca A, Arroyo J, Blanco N, Servillo G, Sanglard D, Reichard U, Palmer GE, Latgè JP, Puccetti P, Romani L
    Sensing of mammalian IL-17A regulates fungal adaptation and virulence.
Nat Commun. 2012 Feb 21;3:683. doi: 10.1038/ncomms1685.

2011

1: Albarrag AM, Anderson MJ, Howard SJ, Robson GD, Warn PA, Sanglard D, Denning DW.
    Interrogation of related clinical pan-azole-resistant Aspergillus fumigatus strains: G138C, Y431C, and G434C single nucleotide polymorphisms in cyp51A, upregulation of cyp51A, and integration and activation of transposon Atf1 in the cyp51A promoter.
Antimicrob Agents Chemother. 2011 Nov;55(11):5113-21.
2: Alcazar-Fuoli L, Mellado E, Cuenca-Estrella M, Sanglard D.
    Probing the role of point mutations in the cyp51A gene from Aspergillus fumigatus in the model yeast Saccharomyces cerevisiae.
Med Mycol. 2011 Apr;49(3):276-84.
3: Ferrari S, Sanguinetti M, De Bernardis F, Torelli R, Posteraro B, Vandeputte P, Sanglard D.
    Loss of mitochondrial functions associated with azole resistance in Candida glabrata results in enhanced virulence in mice.
Antimicrob Agents Chemother. 2011 May;55(5):1852-60.
4: Ferrari S, Sanguinetti M, Torelli R, Posteraro B, Sanglard D.
    Contribution of CgPDR1-regulated genes in enhanced virulence of azole-resistant Candida glabrata.
PLoS One. 2011 Mar 9;6(3):e17589.
5: Florio AR, Ferrari S, De Carolis E, Torelli R, Fadda G, Sanguinetti M, Sanglard D, Posteraro B.
    Genome-wide expression profiling of the response to short-term exposure to fluconazole in Cryptococcus neoformans serotype A.
BMC Microbiol. 2011 May 11;11:97.
6: Kofla G, Turner V, Schulz B, Storch U, Froelich D, Rognon B, Coste AT, Sanglard D, Ruhnke M.
    Doxorubicin induces drug efflux pumps in Candida albicans.
Med Mycol. 2011 Feb;49(2):132-42.
7: Siikala E, Bowyer P, Richardson M, Saxen H, Sanglard D, Rautemaa R.
    ADH1 expression inversely correlates with CDR1 and CDR2 in Candida albicans from chronic oral candidosis in APECED (APS-I) patients.
FEMS Yeast Res. 2011 Sep;11(6):494-8.
8: Vandeputte P, Ischer F, Sanglard D, Coste AT.
    In vivo systematic analysis of Candida albicans Zn2-Cys6 transcription factors mutants for mice organ colonization.
PLoS One. 2011;6(10):e26962.

2010

1: MacCallum DM, Coste A, Ischer F, Jacobsen MD, Odds FC, Sanglard D.
    Genetic dissection of azole resistance mechanisms in Candida albicans and their validation in a mouse model of disseminated infection.
Antimicrob Agents Chemother. 2010 Apr;54(4):1476-83.
2: Manoharlal R, Gorantala J, Sharma M, Sanglard D, Prasad R.
    PAP1 [poly(A) polymerase 1] homozygosity and hyperadenylation are major determinants of increased mRNA stability of CDR1 in azole-resistant clinical isolates of Candida albicans.
Microbiology. 2010 Feb;156(Pt 2):313-26.
3: Siikala E, Rautemaa R, Richardson M, Saxen H, Bowyer P, Sanglard D.
    Persistent Candida albicans colonization and molecular mechanisms of azole resistance in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) patients.
J Antimicrob Chemother. 2010 Dec;65(12):2505-13.

2009

1: Coste AT, Crittin J, Bauser C, Rohde B, Sanglard D.
    Functional analysis of cis- and trans-acting elements of the Candida albicans CDR2 promoter with a novel promoter reporter system.
Eukaryot Cell. 2009 Aug;8(8):1250-67.
2: Ferrari S, Ischer F, Calabrese D, Posteraro B, Sanguinetti M, Fadda G, Rohde B, Bauser C, Bader O, Sanglard D.
    Gain of function mutations in CgPDR1 of Candida glabrata not only mediate antifungal resistance but also enhance virulence.
PLoS Pathog. 2009 Jan;5(1):e1000268.
3: Sanglard D, Coste A, Ferrari S.
    Antifungal drug resistance mechanisms in fungal pathogens from the perspective of transcriptional gene regulation.
FEMS Yeast Res. 2009 Oct;9(7):1029-50.

2008

1: Coste AT, Ramsdale M, Ischer F, Sanglard D.
    Divergent functions of three Candida albicans zinc-cluster transcription factors (CTA4, ASG1 and CTF1) complementing pleiotropic drug resistance in Saccharomyces cerevisiae.
Microbiology. 2008 May;154(Pt 5):1491-501.
2: Torelli R, Posteraro B, Ferrari S, La Sorda M, Fadda G, Sanglard D, Sanguinetti M.
    The ATP-binding cassette transporter-encoding gene CgSNQ2 is contributing to the CgPDR1-dependent azole resistance of Candida glabrata.
Mol Microbiol. 2008 Apr;68(1):186-201.

2007

1: Coste A, Selmecki A, Forche A, Diogo D, Bougnoux ME, d'Enfert C, Berman J, Sanglard D.
    Genotypic evolution of azole resistance mechanisms in sequential Candida albicans isolates.
Eukaryot Cell. 2007 Oct;6(10):1889-904.
2: Pascual A, Nieth V, Calandra T, Bille J, Bolay S, Decosterd LA, Buclin T, Majcherczyk PA, Sanglard D, Marchetti O.
    Variability of voriconazole plasma levels measured by new high-performance liquid chromatography and bioassay methods.
Antimicrob Agents Chemother. 2007 Jan;51(1):137-43.

2006

1: Coste, A., V. Turner, F. Ischer, J. Morschhauser, A. Forche, A. Selmecki, J. Berman, J. Bille, and D. Sanglard
    A mutation in Tac1p, a transcription factor regulating CDR1 and CDR2, is coupled with loss of heterozygosity at chromosome 5 to mediate antifungal resistance in Candida albicans.
Genetics 172:2139-56.
2: Karababa, M., E. Valentino, G. Pardini, A. T. Coste, J. Bille, and D. Sanglard
    CRZ1, a target of the calcineurin pathway in Candida albicans.
Mol Microbiol 59:1429-51.
3: Pardini, G., De Groot, P. W. J., Coste, A. T., Karababa, M., Klis, F. M., de Koster, C. G. and D. Sanglard
    The CRH family coding for cell wall GPI proteins with a predicted transglycosidase domain affects cell wall organization and virulence of Candida albicans.
J Biol Chem. 2006 Dec 29;281(52):40399-411.
4: Rognon, B., Kozovska, Z., Coste, A. T., Pardini, G. and D. Sanglard
    Identification of promoter elements responsible for the regulation of MDR1 from Candida albicans, a major facilitator transporter involved in azole resistance.
Microbiology 152, 3701-3722.

2005

1: Braun, B. R., M. van Het Hoog, C. d'Enfert, M. Martchenko, J. Dungan, A. Kuo, D. O. Inglis, M. A. Uhl, H. Hogues, M. Berriman, M. Lorenz, A. Levitin, U. Oberholzer, C. Bachewich, D. Harcus, A. Marcil, D. Dignard, T. Iouk, R. Zito, L. Frangeul, F. Tekaia, K. Rutherford, E. Wang, C. A. Munro, S. Bates, N. A. Gow, L. L. Hoyer, G. Kohler, J. Morschhauser, G. Newport, S. Znaidi, M. Raymond, B. Turcotte, G. Sherlock, M. Costanzo, J. Ihmels, J. Berman, D. Sanglard, N. Agabian, A. P. Mitchell, A. D. Johnson, M. Whiteway, and A. Nantel
    A human-curated annotation of the Candida albicans genome.
PLoS Genet 1:36-57.
2: Meneau, I., and D. Sanglard
    Azole and fungicide resistance in clinical and environmental Aspergillus fumigatus isolates.
Med Mycol 43 Suppl 1:S307-11.

2004

1: Coste, A. T., M. Karababa, F. Ischer, J. Bille, and D. Sanglard
    TAC1, transcriptional activator of CDR genes, is a new transcription factor involved in the regulation of Candida albicans ABC transporters CDR1 and CDR2.
Eukaryot Cell 3:1639-52.
2: Karababa, M., A. T. Coste, B. Rognon, J. Bille, and D. Sanglard
    Comparison of gene expression profiles of Candida albicans azole-resistant clinical isolates and laboratory strains exposed to drugs inducing multidrug transporters.
Antimicrob Agents Chemother 48:3064-79.


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