Investigation of new targets and antifungal molecules on Candida spp. and Cryptococcus spp.

Abstract

Invasive fungal infections (IFIs) lead a serious health risk resulting in high rates of mortality and morbidity. Among IFIs, Candida albicans represent 50-70% of the cases, followed by Cryptococcus, Aspergillus and Pneumocystis. However, resistant and emerging fungal species have often been isolated, such as Candida auris considered a superfungus. In addition to resistance to antifungal agents, other limitations such as high toxicity, unfavorable pharmacokinetics, high cost and unavailability, further reduce the therapeutic options for fungal infections. Thus, new antifungal molecules are being researched in recent years, addressing new chemical classes and new targets in the fungal cell. Therefore, this project aims to investigate new fungal targets, such as C. auris dihydrofolate reductase (CaDHFR) and Cryptococus neoformans urease (CnURE) enzymes, and to evaluate the in vitro and in vivo antifungal activity of CaDHFR and CnURE inhibitors and synthetic molecules on Candida spp. and Cryptococcus spp. The strategies for this study will be: i) clone, express and purify the CaDHFR and CnURE enzymes; ii) crystallize and resolve the CaDHFR and CnURE structures; iii) evaluate the inhibitory effect and the molecular interaction of the inhibitors with CaDHFR and CnURE enzymes; iv) screening a library of synthetic compounds; v) select molecules with antifungal potential; vi) evaluate the fungicidal and antibiofilm effects; vii) evaluate the combination with conventional antifungals; viii) prospecting for the possible molecular target of the compounds using a library of Saccharomyces cerevisiae mutants; ix) evaluate the morphophysiological effects of the compounds; x) Analyse the toxicity of compounds on cell lines and on Galleria mellonella larval model; and finally, xi) evaluate the in vivo antifungal effect of the compounds using G. mellonella and murine infected by Candida spp. or Cryptococcus spp. (AU)