Trypanosoma brucei CYP51: Essentiality and Targeting Therapy in an Experimental Model

• Published in: PLoS neglected tropical diseases 2016-11, Vol.10 (11), p.e0005125
• Main Authors: Dauchy, Frédéric-Antoine, Bonhivers, Mélanie, Landrein, Nicolas, Dacheux, Denis, Courtois, Pierrette, Lauruol, Florian, Daulouède, Sylvie, Vincendeau, Philippe, Robinson, Derrick R
• Format: Article
• Language: English
• Subjects: 14-alpha Demethylase Inhibitors - pharmacology; Analysis; Animals; Anti-Bacterial Agents - therapeutic use; Biology and Life Sciences; Colleges & universities; Cytochrome P-450; Cytokinesis; Disease Models, Animal; Doxycycline - therapeutic use; Eflornithine - therapeutic use; Enzymes; Ergosterol - pharmacology; Funding; Health aspects; Hospitals; Humans; Life Sciences; Medicine and Health Sciences; Mice; Microbiology and Parasitology; Nifurtimox - therapeutic use; Parasites; Parasitic diseases; Phenotype; Physiological aspects; Research and Analysis Methods; RNA Interference; Sterol 14-Demethylase - genetics; Sterol 14-Demethylase - metabolism; Sterols; Triazoles; Triazoles - pharmacology; Triazoles - therapeutic use; Tropical diseases; Trypanocidal Agents - therapeutic use; Trypanosoma brucei; Trypanosoma brucei brucei - drug effects; Trypanosoma brucei brucei - enzymology; Trypanosoma brucei brucei - growth & development; Trypanosoma brucei brucei - pathogenicity; Trypanosomiasis, African - drug therapy; Trypanosomiasis, African - parasitology; Virulence (Microbiology)
• ISSN: 1935-2735; 1935-2727; 1935-2735
• DOI: 10.1371/journal.pntd.0005125

Trypanosoma brucei gambiense is the main causative agent of Human African Trypanosomiasis (HAT), also known as sleeping sickness. Because of limited alternatives and treatment toxicities, new therapeutic options are urgently needed for patients with HAT. Sterol 14alpha-demethylase (CYP51) is a potential drug target but its essentiality has not been determined in T. brucei. We used a tetracycline-inducible RNAi system to assess the essentiality of CYP51 in T. brucei bloodstream form (BSF) cells and we evaluated the effect of posaconazole, a well-tolerated triazole drug, within a panel of virulent strains in vitro and in a murine model. Expression of CYP51 in several T. brucei cell lines was demonstrated by western blot and its essentiality was demonstrated by RNA interference (CYP51RNAi) in vitro. Following reduction of TbCYP51 expression by RNAi, cell growth was reduced and eventually stopped compared to WT or non-induced cells, showing the requirement of CYP51 in T. brucei. These phenotypes were rescued by addition of ergosterol. Additionally, CYP51RNAi induction caused morphological defects with multiflagellated cells (p