Mafalda Cavalheiro

Class 2016Mafalda Cavalheiro

 

PhD thesis

Deciphering Mechanisms of Pathogenesis in Candida glabrata: in the Crossroad Between Drug Resistance and Virulence

 

Supervisor

• Miguel C Teixeira, Professor @ IST/ULisboa, PT

Collaborators

• Etienne Dague, LAAS-CNRS, Toulouse, France

 

Thesis summary

In this thesis, the study of molecular mechanisms simultaneously involved in at least two of the three main processes for the survival of C. glabrata in the human host: biofilm formation, virulence and antifungal resistance; was pursued. This work presents two new regulators of biofilm formation, CgEfg1 and CgTec1, which together control 40% of all the transcriptomic changes happening in this complex process. In addition, biofilm formation was found to depend on unexpected players, like CgDtr1 and CgTpo4, which are key effectors of virulence in thispathogenic yeast, CgDtr1 as an acetate exporter whose action fights oxidative and acetic acid stress, while CgTpo4 is essential to resist the action of antimicrobial peptides and polyamines. Biofilm formation was also found to rely on the expression of two cell peripheral proteins, CgEpa3 and CgPil2, an adhesin and an eisosome component unraveled during the study of in vitro evolution towards azole resistance of a C. glabrata susceptible clinical isolate. CgEpa3 and CgPil2 are thus two effectors in azole resistance, the first believed to contribute to increased yeast aggregation, decreasing C. glabrata exposure to azole drugs, while CgPil2 contributes for lipid homeostasis at the plasma membrane, influencing the presence of MDR transporters involved in both antifungal resistance and biofilm formation. Altogether, this thesis gives evidence of new molecular mechanisms with intricate functions in biofilm formation, virulence and antifungal resistance, indicating that new therapeutic targets should be chosen according to their importance in as many fundamental roles in C. glabrata as possible.

 

PUBLICATIONS

Papers

Santos, R., Cavalheiro, M., Costa, C., Takahashi-Nakaguchi, A., Okamoto, M., Chibana, H., Teixeira, M.C., “Screening the Drug:H+ Antiporter family for a role in biofilm formation in Candida glabrata”, Frontiers in Cellular and Infection Microbiology, 10: 29, 2020.

Monteiro, P.T., Oliveira, J., Pais, P., Antunes, M., Palma, M., Cavalheiro, M., Galocha, M., Godinho, C.P., Martins, L.C., Bourbon, N., Mota, M.N., Ribeiro, R.A., Viana, R., Sá-Correia, I., Teixeira, M.C., “YEASTRACT+: a portal for cross-species comparative genomics of transcription regulation in yeasts”, Nucleic Acids Research, 48: D642-D649, 2020.

Galocha, M., Pais, P., Cavalheiro, M., Pereira, D., Viana, R., Teixeira, M.C., “Divergent approaches to virulence in C. albicans and C. glabrata: two sides of the same coin”, International Journal of Molecular Sciences, 20(9). pii: E2345, 2019.

Pais, P., Galocha, M., Viana, R., Cavalheiro, M., Pereira, D., Teixeira, M.C., “Microevolution of the pathogenic yeasts Candida albicans and Candida glabrata during antifungal therapy and host infection”, Microbial Cell, 6(3): 142 – 159, 2019.

Cavalheiro, M., Costa, C., Silva-Dias, A., Miranda, I.M., Wang, C., Pais, P., Pinto, S.N., Mil-Homens, D., Sato-Okamoto, M., Takahashi-Nakaguchi, A., Silva, R.M., Mira, N.P., Fialho, A.M., Chibana, H., Rodrigues, A.G., Butler, G., Teixeira, M.C., “Unveiling the mechanisms of in vitro evolution towards fluconazole resistance of a Candida glabrata clinical isolate: a transcriptomics approach”, Antimicrobial Agents and Chemotherapy, 63: e00995-18, 2019.

Cavalheiro, M., Pais, P., Galocha, M., Teixeira, M.C., “Host-pathogen interactions mediated by MDR transporters in fungi: as pleiotropic as it gets!”, Genes, 9: 332, 2018.

Cavalheiro, M., Teixeira, M.C., “Candida biofilms: threats, challenges and promising strategies”, Frontiers in Medicine, 5: 28, 2018.

Romão, D.*, Cavalheiro, M.*, Mil-Homens, D., Santos, R., Pais, P., Costa, C., Takahashi-Nakaguchi, A., Fialho, A.M., Hiroji Chibana, H.**, Teixeira, M.C.**, “A new determinant of Candida glabrata virulence: the acetate exporter CgDtr1″, Frontiers in Cellular and Infection Microbiology, 7: 473, 2017.

Oral Communications

Cavalheiro M, Costa C, Wang C, Silva-Dias A, Miranda IM, Silva RM, Rodrigues AG, Butler G, Teixeira MC, Transcriptomic Analysis of the in vitro Evolution of a Susceptible Candida glabrata Clinical Isolate towards Azole Resistance”, Annual Meeting of the Portuguese Society of Genetics, 14-15 June 2018, Porto, Portugal.

 

Poster Communications

Cavalheiro M, Santos R, Romão D, Mil-Homens D, Pais P, Costa C, Viana R, Santos S, Fialho AM, Teixeira MC, “Determining virulence by protecting the cell from host induced stresses: the unexpected role of C. glabrata multidrug transporters”, MicroBiotec2017, December 7-8, 2017, Porto, Portugal (best poster presentation award)

Cavalheiro M, Santos R, Romão D, Mil-Homens D, Pais P, Costa C, Galocha M, Fialho AM, Teixeira MC, “A new role for C. glabrata drug:H+ antiporters: in the crossroad between drug resistance and virulence”, HFP2017 – Advanced Lecture Course in Molecular Mechanisms of Host-Pathogen Interactions and Virulence in Human Fungal Pathogens, May 13-19, 2017, La Colle sur Loup, France

Cavalheiro M, Costa C, Wang C, Silva-Dias A, Miranda IM, Rodrigues AG, Butler G, Teixeira MC, “Determining the molecular mechanisms behind the in vitro evolution of a susceptible Candida glabrata clinical isolate towards azole resistance”, 14th ASM Conference on Candida and Candidiasis,April 15-19, 2018, Providence, RI, USA

Cavalheiro M, Costa C, Silva-Dias A, Miranda IM, Chibana H, Rodrigues AG, Butler G, Teixeira MC, “New insights into the clinical acquisition of azole resistance: witnessing Candida glabrata evolution”, 29th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID), 13-16 April 2019, Amsterdam, The Netherlands

 

DOCTORAL PROGRAM (36 ECTS)

• General Doctoral Training (6 ECTS)

• Advanced Experimental Techniques and methodologies (6 ECTS)

• Bioentrepreneurship (6 ECTS)

• Outreach and Teaching Skills (6 ECTS)

• Structural Biology (6 ECTS)

• Gene Therapy (6 ECTS)

Advanced courses: Genome Assembly and Annotation Course, by Elixir, 23-27 October 2017, Instituto Gulbenkian Ciência, Oeiras, Portugal