Susan Wyllie

Susan Wyllie
University of Dundee · Wellcome Centre for Anti-infectives Research

BSc (Hons), PhD

About

115
Publications
16,163
Reads
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3,391
Citations
Introduction
My research is focused on determining drug mechanisms of action and mechanism of drug resistance in protozoan parasites - in particular in Leishmania spp the causative agent of visceral leishmaniasis.
Additional affiliations
June 2019 - present
University of Dundee
Position
  • Principal Investigator
February 2017 - May 2019
University of Dundee
Position
  • Independent Investigator, Mechanism of Action Group
September 2001 - January 2017
University of Dundee
Position
  • Lecturer

Publications

Publications (115)
Article
Full-text available
Artemisinin-based combination therapies have been crucial in driving down the global burden of malaria, the world's largest parasitic killer. However, their efficacy is now threatened by the emergence of resistance in Southeast Asia and sub-Saharan Africa. Thus, there is a pressing need to develop new antimalarials with diverse mechanisms of action...
Article
Trypanosomatids cause the neglected tropical diseases, sleeping sickness, Chagas disease and the leishmaniases. Studies on these lethal parasites would be further facilitated by new and improved genetic technologies. Scalable precision editing methods, for example, could be used to improve our understanding of potential mutations associated with dr...
Article
Full-text available
African animal trypanosomiasis or nagana, caused principally by infection of the protozoan parasites Trypanosoma congolense and Trypanosoma vivax, is a major problem in cattle and other livestocks in sub-Saharan Africa. Current treatments are threatened by the emergence of drug resistance and there is an urgent need for new, effective drugs. Here,...
Article
Full-text available
Visceral leishmaniasis (VL) is a parasitic disease endemic across multiple regions of the world and is fatal if untreated. Current therapies are unsuitable, and there is an urgent need for safe, short-course, and low-cost oral treatments to combat this neglected disease. The benzoxaborole chemotype has previously delivered clinical candidates for t...
Article
Full-text available
Chagas disease, caused by the protozoan intracellular parasite Trypanosoma cruzi, is a highly neglected tropical disease, causing significant morbidity and mortality in central and south America. Current treatments are inadequate, and recent clinical trials of drugs inhibiting CYP51 have failed, exposing a lack of understanding of how to translate...
Article
Full-text available
Phenotypic screening identified an arylsulfonamide compound with activity against Trypanosoma cruzi , the causative agent of Chagas’ disease. Comprehensive mode of action studies revealed that this compound primarily targets the T. cruzi proteasome, binding at the interface between β4 and β5 subunits that catalyse chymotrypsin-like activity. A muta...
Article
Full-text available
There is a shift in antimalarial drug discovery from phenotypic screening toward target-based approaches, as more potential drug targets are being validated in Plasmodium species. Given the high attrition rate and high cost of drug discovery, it is important to select the targets most likely to deliver progressible drug candidates. In this paper, w...
Article
Full-text available
Here, we detail our optimized protocol for the identification of drug targets in Leishmania donovani using thermal proteome profiling. This approach is based on the principle that binding of a drug to its protein target can significantly alter the thermal stability of that protein. By monitoring changes in the thermal stability of proteins within d...
Article
Full-text available
Current treatment options for visceral leishmaniasis have several drawbacks, and clinicians are confronted with an increasing number of treatment failures. To overcome this, the Drugs for Neglected Diseases initiative (DNDi) has invested in the development of novel antileishmanial leads, including a very promising class of oxaboroles. The mode of a...
Article
Full-text available
Phenotypic screening identified a benzothiophene compound with activity against Leishmania donovani, the causative agent of visceral leishmaniasis. Using multiple orthogonal approaches, oxidosqualene cyclase (OSC), a key enzyme of sterol biosynthesis, was identified as the target of this racemic compound and its enantiomers. Whole genome sequencing...
Article
Full-text available
Protein and phosphoinositide kinases have been successfully exploited as drug targets in various disease areas, principally in oncology. In malaria, several protein kinases are under investigation as potential drug targets, and an inhibitor of Plasmodium phosphatidylinositol 4-kinase type III beta (PI4KIIIβ) is currently in phase 2 clinical studies...
Article
Full-text available
The Malaria Drug Accelerator (MalDA) is a consortium of 15 leading scientific laboratories. The aim of MalDA is to improve and accelerate the early antimalarial drug discovery process by identifying new, essential, druggable targets. In addition, it seeks to produce early lead inhibitors that may be advanced into drug candidates suitable for precli...
Article
To study the antikinetoplastid 3-nitroimidazo[1,2-a]pyridine pharmacophore, a structure-activity relationship study was conducted through the synthesis of 26 original derivatives and their in vitro evaluation on both Leishmania spp and Trypanosoma brucei brucei. This SAR study showed that the antitrypanosomal pharmacophore was less restrictive than...
Article
Full-text available
Visceral leishmaniasis (VL) is a parasitic infection that results in approximately 26,000 – 65,000 deaths annually. The available treatments are hampered by issues such as toxicity, variable efficacy and unsuitable dosing options. The need for new treatments is urgent and led to a collaboration between the Drugs for Neglected Diseases initiative (D...
Article
An antikinetoplastid pharmacomodulation study was done at position 8 of a previously identified pharmacophore in 3-nitroimidazo[1,2-a]pyridine series. Twenty original derivatives bearing an alkynyl moiety were synthesized via a Sonogashira cross-coupling reaction and tested in vitro, highlighting 3 potent (40 nM ≤ EC50 blood stream form≤ 70 nM) and...
Article
Full-text available
An antikinetoplastid pharmacomodulation study was conducted at position 6 of the 8-nitroquinolin-2(1H)-one pharmacophore. Fifteen new derivatives were synthesized and evaluated in vitro against L. infantum, T. brucei brucei and T. cruzi, in parallel with a cytotoxicity assay on the human HepG2 cell line. A potent and selective 6-bromo-substituted a...
Article
Full-text available
Available treatments for Chagas’ disease and visceral leishmaniasis are inadequate and there is a pressing need for new therapeutics. Drug discovery efforts for both diseases principally rely upon phenotypic screening. However, the optimisation of phenotypically-active compounds is hindered by a lack of information regarding their molecular target(...
Article
Full-text available
In May 2019, the Wellcome Centre for Anti-Infectives Research (WCAIR) at the University of Dundee, UK, held an international conference with the aim of discussing some key questions around discovering new medicines for infectious diseases and a particular focus on diseases affecting Low and Middle Income Countries. There is an urgent need for new d...
Article
Full-text available
Visceral leishmaniasis (VL), caused by the protozoan parasites Leishmania donovani and Leishmania infantum , is one of the major parasitic diseases worldwide. There is an urgent need for new drugs to treat VL, because current therapies are unfit for purpose in a resource-poor setting. Here, we describe the development of a preclinical drug candidat...
Article
Full-text available
Twenty nine original 3-nitroimidazo[1,2-a]pyridine derivatives, bearing a phenylthio (or benzylthio) moiety at position 8 of the scaffold, were synthesized. In vitro evaluation highlighted compound 5 as an antiparasitic hit molecule displaying low cytotoxicity for the human HepG2 cell line (CC50 > 100 µM) alongside good antileish-manial activities...
Article
Full-text available
Visceral leishmaniasis (VL), caused by the protozoan parasites Leishmania donovani and L. infantum, is responsible for ~30,000 deaths annually. Available treatments are inadequate and there is a pressing need for new therapeutics. N-Myristoyltransferase (NMT) remains one of the few genetically validated drug targets in these parasites. Here, we sou...
Article
Full-text available
The folate pathway has been extensively studied in a number of organisms, with its essentiality exploited by a number of drugs. However, there has been little success in developing drugs that target folate metabolism in the kinetoplastids. Despite compounds being identified which show significant inhibition of the parasite enzymes, this activity do...
Article
An antikinetoplastid pharmacomodulation study at position 3 of the recently described hit molecule 3‐bromo‐8‐nitroquinolin‐2(1H)‐one was conducted. Twenty‐four derivatives were synthesised using the Suzuki–Miyaura cross‐coupling reaction and evaluated in vitro on both Leishmania infantum axenic amastigotes and Trypanosoma brucei brucei trypomastigo...
Article
African trypanosomes cause lethal and neglected tropical diseases, known as sleeping sickness in humans and nagana in animals. Current therapies are limited, but fortunately, promising therapies are in advanced clinical and veterinary development, including acoziborole (AN5568 or SCYX-7158) and AN11736, respectively. These benzoxaboroles will likel...
Article
Based on a previously identified antileishmanial 6,8-dibromo-3-nitroimidazo[1,2-a]pyridine derivative, a Suzuki-Miyaura coupling reaction at position 8 of the scaffold was studied and optimized from a 8-bromo-6-chloro-3-nitroimidazo[1,2-a]pyridine substrate. Twenty-one original derivatives were prepared , screened in vitro for activity against L. i...
Article
The structures of nifurtimox in Table 1 were incorrect and have been updated in the pdf and online. The authors apologize for any confusion caused.
Article
Full-text available
Visceral leishmaniasis causes considerable mortality and morbidity in many parts of the world. There is an urgent need for the development of new, effective treatments for this disease. Here we describe the development of an anti-leishmanial drug-like chemical series based on a pyrazolopyrimidine scaffold. The leading compound from this series (7,...
Article
To study the antiparasitic 8-nitroquinolin-2(1H)-one pharmacophore, a series of 31 derivatives was synthesized in 1-5 steps and evaluated in vitro against both Leishmania infantum and Trypanosoma brucei brucei. In parallel, the reduction potential of all molecules was measured by cyclic voltammetry. Structure-activity relationships first indicated...
Article
Full-text available
Lack of information regarding the mechanisms of action (MoA) or specific molecular targets of phenotypically active compounds can prove a barrier to their development as chemotherapeutic agents. Here, we report the results of our orthogonal genetic, molecular and biochemical studies to determine the MoA of a novel 7-substituted 8-hydroxy-1,6-naphth...
Article
Full-text available
Methionyl-tRNA synthetase (MetRS) has been chemically validated as a drug target in the kinetoplastid parasite Trypanosoma brucei. In the present study, we investigate the validity of this target in the related trypanosomatid Leishmania donovani. Following development of a robust high-throughput compatible biochemical assay, a compound screen ident...
Article
The WHO recognizes human African trypanosomiasis, Chagas disease and the leishmaniases as neglected tropical diseases. These diseases are caused by parasitic trypanosomatids and range in severity from mild and self-curing to near invariably fatal. Public health advances have substantially decreased the effect of these diseases in recent decades but...
Article
This study characterised in vitro potencies of anti-leishmanial agents against intracellular Leishmania donovani amastigotes in primary human macrophages, obtained with or without CD14-positive monocyte enrichment, phorbol 12-myristate 13-acetate (PMA) differentiated THP-1 cells and mouse peritoneal exudate macrophages (PEMs). Host cell dependent p...
Article
Full-text available
Drug discovery pipelines for the " neglected diseases " are now heavily populated with nitroheterocyclic compounds. Recently, the bicyclic nitro-compounds (R)-PA-824, DNDI-VL-2098 and delamanid have been identified as potential candidates for the treatment of visceral leishmaniasis. Using a combination of quantitative proteomics and whole genome se...
Article
Full-text available
Drug discovery pipelines for the ªneglected diseasesº are now heavily populated with nitroheterocyclic compounds. Recently, the bicyclic nitro-compounds (R)-PA-824, DNDIVL- 2098 and delamanid have been identified as potential candidates for the treatment of visceral leishmaniasis. Using a combination of quantitative proteomics and whole genome sequ...
Data
List of proteins found to be consistently over- or under-expressed in RES III compared to WT promastigotes (see accompanying Excel document). (XLSX)
Data
List of SNPs and INDELs identified in drug resistant clones (see accompanying Excel document). (XLSX)
Data
Procedures for the synthesis of DNDI-VL-2098, CGI-17341 and delamanid. (DOCX)
Data
Susceptibility of RES III and WT parasites to (R)-PA-824 in the intra-macrophage amastigote stage. WT (open circles) and RES III (closed circles) metacyclic promastigotes were used to infect starch-elicited, mouse peritoneal macrophages. Dose response curves are the non-linear regression fits using a four-parameter EC50 equation, yielding EC50 valu...
Data
Levels of NTR2 in WT, RES III and NTR2 overexpressing promastigotes. WT (open circles) and RES III (closed circles) metacyclic promastigotes were used to infect starch-elicited, mouse peritoneal macrophages. Dose response curves are the non-linear regression fits using a four-parameter EC50 equation, yielding EC50 values of 2.1 ± 0.15 μM and > 50 μ...
Data
Cloning primers used to generate over-expressing and knockout lines of L. donovani and recombinant expression in E.coli. (DOCX)
Data
Efficacy and PK/PD data from all experiments.DOI: http://dx.doi.org/10.7554/eLife.09744.008
Article
Full-text available
There is an urgent requirement for safe, oral and cost-effective drugs for the treatment of visceral leishmaniasis (VL). We report that delamanid (OPC-67683), an approved drug for multi-drug resistant tuberculosis, is a potent inhibitor of Leishmania donovani both in vitro and in vivo. Twice-daily oral dosing of delamanid at 30 mg kg(-1) for 5 days...
Article
Full-text available
Objectives The objective of this study was to identify the mechanisms of resistance to nifurtimox and fexinidazole in African trypanosomes. Methods Bloodstream-form Trypanosoma brucei were selected for resistance to nifurtimox and fexinidazole by stepwise exposure to increasing drug concentrations. Clones were subjected to WGS to identify putative...
Article
Full-text available
Objectives: In response to reports of Trypanosoma brucei resistance to the nitroaromatic drug nifurtimox, we evaluated the potential of antituberculosis nitrofuran isoxazolines as inhibitors of trypanosome growth. Methods: The susceptibility of T. brucei brucei was assessed in vitro. The lowest effective concentration to inhibit growth (EC90) ag...
Research
Full-text available
Objectives: The objective of this study was to identify the mechanisms of resistance to nifurtimox and fexinidazole in African trypanosomes. Methods: Bloodstream-form Trypanosoma brucei were selected for resistance to nifurtimox and fexinidazole by stepwise exposure to increasing drug concentrations. Clones were subjected to WGS to identify putativ...
Article
In Bihar state, India, the cure rate of antimonial compounds (eg, sodium stibogluconate) in the treatment of visceral leishmaniasis (VL) has fallen from more than 85% to less than 50%. This reduction has been attributed to long-term, widespread misuse of antimonial drugs within the Indian private health-care system. We aimed to test the hypothesis...
Article
Full-text available
De novo synthesis of threonine from aspartate occurs via the β-aspartyl phosphate pathway in plants, bacteria and fungi. However, the Trypanosoma brucei genome encodes only the last two steps in this pathway: homoserine kinase (HSK) and threonine synthase. Here, we investigated the possible roles for this incomplete pathway through biochemical, gen...