Selective molecular approaches to remove trypanosomiasis
African trypanosomiasis (AT), caused by the protozoan parasite Trypanosoma spp., is a debilitating disease that threatens millions of people in Sub-Saharan Africa. The human disease evolves in two stages, the second of which causes a fatal neurological infection if left untreated. The recent discovery of the orally-bioavailable drug fexinidazole, and its current use as a first-line treatment, has significantly improved disease outcomes associated with AT. However, the risk of resistance to fexinidazole treatment is a major concern that highlights the need for new treatment options. G-quadruplexes (G4s) are non-canonical DNA secondary structures that have recently emerged as an attractive target to fight AT. For example, recent studies have revealed the killing properties of a well-characterised G4-ligand, quarfloxin, against T. brucei parasites, showing the great potential for G4-targeting approaches to treat AT. However, the fundamental role of G4s in trypanosome biology and their validation as therapeutic targets have not been elucidated. In this proposal, I aim to unravel the biological functions of G4s in trypanosomes using integrated chemistry and genomic approaches. Specifically, peptide-based molecules designed to selectively target trypanosome G4s (TG4) will be developed and biophysically validated. The TG4-selective peptides will be used to functionally interrogate the trypanosome genome and to understand the effect of G4-modulation on gene expression using transcriptomics. Finally, our peptides will be engineered into fluorescent probes to facilitate real-time molecular visualisations of TG4s formation in vitro, and to provide an in-depth characterisation of these structures as novel targets to combat AT.