Publications by authors named "Robert J Watson"

37 Publications

Template-Hopping Approach Leads to Potent, Selective, and Highly Soluble Bromo and Extraterminal Domain (BET) Second Bromodomain (BD2) Inhibitors.

J Med Chem 2021 Mar 4;64(6):3249-3281. Epub 2021 Mar 4.

Epigenetics Discovery Performance Unit, GlaxoSmithKline, Medicines Research Centre, Stevenage, Hertfordshire SG1 2NY, U.K.

A number of reports have recently been published describing the discovery and optimization of bromo and extraterminal inhibitors which are selective for the second bromodomain (BD2); these include our own work toward GSK046 () and GSK620 (). This paper describes our approach to mitigating the genotoxicity risk of GSK046 by replacement of the acetamide functionality with a heterocyclic ring. This was followed by a template-hopping and hybridization approach, guided by structure-based drug design, to incorporate learnings from other BD2-selective series, optimize the vector for the amide region, and explore the ZA cleft, leading to the identification of potent, selective, and bioavailable compounds (GSK452), (GSK737), and (GSK217).
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http://dx.doi.org/10.1021/acs.jmedchem.0c02156DOI Listing
March 2021

Comparison of rhesus and cynomolgus macaques as an infection model for COVID-19.

Nat Commun 2021 02 24;12(1):1260. Epub 2021 Feb 24.

National Infection Service, Public Health England (PHE), Porton Down, Salisbury, Wiltshire, UK.

A novel coronavirus, SARS-CoV-2, has been identified as the causative agent of the current COVID-19 pandemic. Animal models, and in particular non-human primates, are essential to understand the pathogenesis of emerging diseases and to assess the safety and efficacy of novel vaccines and therapeutics. Here, we show that SARS-CoV-2 replicates in the upper and lower respiratory tract and causes pulmonary lesions in both rhesus and cynomolgus macaques. Immune responses against SARS-CoV-2 are also similar in both species and equivalent to those reported in milder infections and convalescent human patients. This finding is reiterated by our transcriptional analysis of respiratory samples revealing the global response to infection. We describe a new method for lung histopathology scoring that will provide a metric to enable clearer decision making for this key endpoint. In contrast to prior publications, in which rhesus are accepted to be the preferred study species, we provide convincing evidence that both macaque species authentically represent mild to moderate forms of COVID-19 observed in the majority of the human population and both species should be used to evaluate the safety and efficacy of interventions against SARS-CoV-2. Importantly, accessing cynomolgus macaques will greatly alleviate the pressures on current rhesus stocks.
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http://dx.doi.org/10.1038/s41467-021-21389-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7904795PMC
February 2021

Dose-dependent response to infection with SARS-CoV-2 in the ferret model and evidence of protective immunity.

Nat Commun 2021 01 4;12(1):81. Epub 2021 Jan 4.

National Infection Service, Public Health England (PHE), Porton Down, Salisbury, Wiltshire, SP4 0JG, UK.

There is a vital need for authentic COVID-19 animal models to enable the pre-clinical evaluation of candidate vaccines and therapeutics. Here we report a dose titration study of SARS-CoV-2 in the ferret model. After a high (5 × 10 pfu) and medium (5 × 10 pfu) dose of virus is delivered, intranasally, viral RNA shedding in the upper respiratory tract (URT) is observed in 6/6 animals, however, only 1/6 ferrets show similar signs after low dose (5 × 10 pfu) challenge. Following sequential culls pathological signs of mild multifocal bronchopneumonia in approximately 5-15% of the lung is seen on day 3, in high and medium dosed groups. Ferrets re-challenged, after virus shedding ceased, are fully protected from acute lung pathology. The endpoints of URT viral RNA replication & distinct lung pathology are observed most consistently in the high dose group. This ferret model of SARS-CoV-2 infection presents a mild clinical disease.
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http://dx.doi.org/10.1038/s41467-020-20439-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7782478PMC
January 2021

Prophylactic intranasal administration of a TLR2/6 agonist reduces upper respiratory tract viral shedding in a SARS-CoV-2 challenge ferret model.

EBioMedicine 2021 Jan 3;63:103153. Epub 2020 Dec 3.

National Infection Service, Public Health England (PHE), Porton Down, Salisbury, Wiltshire, United Kingdom SP4 0JG; Nuffield Dept of Medicine, Oxford University, Oxford, UK. Electronic address:

Background: The novel human coronavirus SARS-CoV-2 is a major ongoing global threat with huge economic burden. Like all respiratory viruses, SARS-CoV-2 initiates infection in the upper respiratory tract (URT). Infected individuals are often asymptomatic, yet highly infectious and readily transmit virus. A therapy that restricts initial replication in the URT has the potential to prevent progression of severe lower respiratory tract disease as well as limiting person-to-person transmission.

Methods: SARS-CoV-2 Victoria/01/2020 was passaged in Vero/hSLAM cells and virus titre determined by plaque assay. Challenge virus was delivered by intranasal instillation to female ferrets at 5.0 × 10 pfu/ml. Treatment groups received intranasal INNA-051, developed by Ena Respiratory. SARS-CoV-2 RNA was detected using the 2019-nCoV CDC RUO Kit and QuantStudio™ 7 Flex Real-Time PCR System. Histopathological analysis was performed using cut tissues stained with haematoxylin and eosin (H&E).

Findings: We show that prophylactic intra-nasal administration of the TLR2/6 agonist INNA-051 in a SARS-CoV-2 ferret infection model effectively reduces levels of viral RNA in the nose and throat. After 5 days post-exposure to SARS-CoV-2, INNA-051 significantly reduced virus in throat swabs (p=<0.0001) by up to a 24 fold (96% reduction) and in nasal wash (p=0.0107) up to a 15 fold (93% reduction) in comparison to untreated animals.

Interpretation: The results of our study support clinical development of a therapy based on prophylactic TLR2/6 innate immune activation in the URT, to reduce SARS-CoV-2 transmission and provide protection against COVID-19.

Funding: This work was funded by Ena Respiratory, Melbourne, Australia.
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http://dx.doi.org/10.1016/j.ebiom.2020.103153DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7711201PMC
January 2021

GSK973 Is an Inhibitor of the Second Bromodomains (BD2s) of the Bromodomain and Extra-Terminal (BET) Family.

ACS Med Chem Lett 2020 Aug 6;11(8):1581-1587. Epub 2020 Jul 6.

Epigenetics Discovery Performance Unit and Platform Technology and Science, GlaxoSmithKline Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, U.K.

Pan-BET inhibitors have shown profound efficacy in a number of in vivo preclinical models and have entered the clinic in oncology trials where adverse events have been reported. These inhibitors interact equipotently with the eight bromodomains of the BET family of proteins. To better understand the contribution of each domain to their efficacy and to improve from their safety profile, selective inhibitors are required. This Letter discloses the profile of GSK973, a highly selective inhibitor of the second bromodomains of the BET proteins that has undergone extensive preclinical in vitro and in vivo characterization.
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http://dx.doi.org/10.1021/acsmedchemlett.0c00247DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7429977PMC
August 2020

Structure-Based Design of a Bromodomain and Extraterminal Domain (BET) Inhibitor Selective for the N-Terminal Bromodomains That Retains an Anti-inflammatory and Antiproliferative Phenotype.

J Med Chem 2020 09 3;63(17):9020-9044. Epub 2020 Aug 3.

GSK, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, United Kingdom.

The bromodomain and extraterminal domain (BET) family of epigenetic regulators comprises four proteins (BRD2, BRD3, BRD4, BRDT), each containing tandem bromodomains. To date, small molecule inhibitors of these proteins typically bind all eight bromodomains of the family with similar affinity, resulting in a diverse range of biological effects. To enable further understanding of the broad phenotype characteristic of pan-BET inhibition, the development of inhibitors selective for individual, or sets of, bromodomains within the family is required. In this regard, we report the discovery of a potent probe molecule possessing up to 150-fold selectivity for the N-terminal bromodomains (BD1s) over the C-terminal bromodomains (BD2s) of the BETs. Guided by structural information, a specific amino acid difference between BD1 and BD2 domains was targeted for selective interaction with chemical functionality appended to the previously developed I-BET151 scaffold. Data presented herein demonstrate that selective inhibition of BD1 domains is sufficient to drive anti-inflammatory and antiproliferative effects.
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http://dx.doi.org/10.1021/acs.jmedchem.0c00566DOI Listing
September 2020

A flexible format LAMP assay for rapid detection of Ebola virus.

PLoS Negl Trop Dis 2020 07 31;14(7):e0008496. Epub 2020 Jul 31.

Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire, United Kingdom.

Background: The unprecedented 2013/16 outbreak of Zaire ebolavirus (Ebola virus) in West Africa has highighted the need for rapid, high-throughput and POC diagnostic assays to enable timely detection and appropriate triaging of Ebola Virus Disease (EVD) patients. Ebola virus is highly infectious and prompt diagnosis and triage is crucial in preventing further spread within community and healthcare settings. Moreover, due to the ecology of Ebola virus it is important that newly developed diagnostic assays are suitable for use in both the healthcare environment and low resource rural locations.

Methodology/principle Findings: A LAMP assay was successfully developed with three detection formats; a real-time intercalating dye-based assay, a real-time probe-based assay to enable multiplexing and an end-point colourimetric assay to simplify interpretation for the field. All assay formats were sensitive and specific, detecting a range of Ebola virus strains isolated in 1976-2014; with Probit analysis predicting limits of detection of 243, 290 and 75 copies/reaction respectively and no cross-detection of related strains or other viral haemorrhagic fevers (VHF's). The assays are rapid, (as fast as 5-7.25 mins for real-time formats) and robust, detecting Ebola virus RNA in presence of minimally diluted bodily fluids. Moreover, when tested on patient samples from the 2013/16 outbreak, there were no false positives and 93-96% of all new case positives were detected, with only a failure to detect very low copy number samples.

Conclusion/significance: These are a set of robust and adaptable diagnostic solutions, which are fast, easy-to-perform-and-interpret and are suitable for use on a range of platforms including portable low-power devices. They can be readily transferred to field-laboratory settings, with no specific equipment needs and are therefore ideally placed for use in locations with limited resources.
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http://dx.doi.org/10.1371/journal.pntd.0008496DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7423149PMC
July 2020

The Optimization of a Novel, Weak Bromo and Extra Terminal Domain (BET) Bromodomain Fragment Ligand to a Potent and Selective Second Bromodomain (BD2) Inhibitor.

J Med Chem 2020 09 30;63(17):9093-9126. Epub 2020 Aug 30.

IVIVT Cellzome, Platform Technology and Science, GlaxoSmithKline, Meyerhofstrasse 1, 69117 Heidelberg, Germany.

The profound efficacy, yet associated toxicity of pan-BET inhibitors is well documented. The possibility of an ameliorated safety profile driven by significantly selective (>100-fold) inhibition of a subset of the eight bromodomains is enticing, but challenging given the close homology. Herein, we describe the X-ray crystal structure-directed optimization of a novel weak fragment ligand with a pan-second bromodomain (BD2) bias, to potent and highly BD2 selective inhibitors. A template hopping approach, enabled by our parallel research into an orthogonal template (, GSK046), was the basis for the high selectivity observed. This culminated in two tool molecules, (GSK620) and (GSK549), which showed an anti-inflammatory phenotype in human whole blood, confirming their cellular target engagement. Excellent broad selectivity, developability, and in vivo oral pharmacokinetics characterize these tools, which we hope will be of broad utility to the field of epigenetics research.
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http://dx.doi.org/10.1021/acs.jmedchem.0c00796DOI Listing
September 2020

Design and Synthesis of a Highly Selective and -Capable Inhibitor of the Second Bromodomain of the Bromodomain and Extra Terminal Domain Family of Proteins.

J Med Chem 2020 09 20;63(17):9070-9092. Epub 2020 Aug 20.

Epigenetics Discovery Performance Unit, GlaxoSmithKline, Medicines Research Centre, Stevenage, Hertfordshire SG1 2NY, U.K.

Pan-bromodomain and extra terminal domain (BET) inhibitors interact equipotently with the eight bromodomains of the BET family of proteins and have shown profound efficacy in a number of phenotypic assays and pre-clinical models in inflammation or oncology. A number of these inhibitors have progressed to the clinic where pharmacology-driven adverse events have been reported. To better understand the contribution of each domain to their efficacy and improve their safety profile, selective inhibitors are required. This article discloses the profile of GSK046, also known as iBET-BD2, a highly selective inhibitor of the second bromodomains of the BET proteins that has undergone extensive pre-clinical and characterization.
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http://dx.doi.org/10.1021/acs.jmedchem.0c00605DOI Listing
September 2020

GSK789: A Selective Inhibitor of the First Bromodomains (BD1) of the Bromo and Extra Terminal Domain (BET) Proteins.

J Med Chem 2020 09 4;63(17):9045-9069. Epub 2020 Aug 4.

Molecular Discovery Research, GlaxoSmithKline, Cellzome GmbH, Meyerhofstrasse 1, 69117 Heidelberg, Germany.

Pan-bromodomain and extra terminal (BET) inhibitors interact equipotently with all eight bromodomains of the BET family of proteins. They have shown profound efficacy in vitro and in vivo in oncology and immunomodulatory models, and a number of them are currently in clinical trials where significant safety signals have been reported. It is therefore important to understand the functional contribution of each bromodomain to assess the opportunity to tease apart efficacy and toxicity. This article discloses the in vitro and cellular activity profiles of GSK789, a potent, cell-permeable, and highly selective inhibitor of the first bromodomains of the BET family.
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http://dx.doi.org/10.1021/acs.jmedchem.0c00614DOI Listing
September 2020

Optimization of Potent ATAD2 and CECR2 Bromodomain Inhibitors with an Atypical Binding Mode.

J Med Chem 2020 05 6;63(10):5212-5241. Epub 2020 May 6.

WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow G1 1XL, United Kingdom.

Most bromodomain inhibitors mimic the interactions of the natural acetylated lysine (KAc) histone substrate through key interactions with conserved asparagine and tyrosine residues within the binding pocket. Herein we report the optimization of a series of phenyl sulfonamides that exhibit a novel mode of binding to non-bromodomain and extra terminal domain (non-BET) bromodomains through displacement of a normally conserved network of four water molecules. Starting from an initial hit molecule, we report its divergent optimization toward the ATPase family AAA domain containing 2 (ATAD2) and cat eye syndrome chromosome region, candidate 2 (CECR2) domains. This work concludes with the identification of (GSK232), a highly selective, cellularly penetrant CECR2 inhibitor with excellent physicochemical properties.
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http://dx.doi.org/10.1021/acs.jmedchem.0c00021DOI Listing
May 2020

Discovery of a Bromodomain and Extraterminal Inhibitor with a Low Predicted Human Dose through Synergistic Use of Encoded Library Technology and Fragment Screening.

J Med Chem 2020 01 6;63(2):714-746. Epub 2020 Jan 6.

GSK , Gunnels Wood Road , Stevenage , Hertfordshire SG1 2NY , U.K.

The bromodomain and extraterminal (BET) family of bromodomain-containing proteins are important regulators of the epigenome through their ability to recognize -acetyl lysine (KAc) post-translational modifications on histone tails. These interactions have been implicated in various disease states and, consequently, disruption of BET-KAc binding has emerged as an attractive therapeutic strategy with a number of small molecule inhibitors now under investigation in the clinic. However, until the utility of these advanced candidates is fully assessed by these trials, there remains scope for the discovery of inhibitors from new chemotypes with alternative physicochemical, pharmacokinetic, and pharmacodynamic profiles. Herein, we describe the discovery of a candidate-quality dimethylpyridone benzimidazole compound which originated from the hybridization of a dimethylphenol benzimidazole series, identified using encoded library technology, with an -methyl pyridone series identified through fragment screening. Optimization via structure- and property-based design led to I-BET469, which possesses favorable oral pharmacokinetic properties, displays activity in vivo, and is projected to have a low human efficacious dose.
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http://dx.doi.org/10.1021/acs.jmedchem.9b01670DOI Listing
January 2020

A Qualified Success: Discovery of a New Series of ATAD2 Bromodomain Inhibitors with a Novel Binding Mode Using High-Throughput Screening and Hit Qualification.

J Med Chem 2019 08 9;62(16):7506-7525. Epub 2019 Aug 9.

GlaxoSmithKline Tres Cantos , 28760 Tres Cantos , Madrid , Spain.

The bromodomain of ATAD2 has proved to be one of the least-tractable proteins within this target class. Here, we describe the discovery of a new class of inhibitors by high-throughput screening and show how the difficulties encountered in establishing a screening triage capable of finding progressible hits were overcome by data-driven optimization. Despite the prevalence of nonspecific hits and an exceptionally low progressible hit rate (0.001%), our optimized hit qualification strategy employing orthogonal biophysical methods enabled us to identify a single active series. The compounds have a novel ATAD2 binding mode with noncanonical features including the displacement of all conserved water molecules within the active site and a halogen-bonding interaction. In addition to reporting this new series and preliminary structure-activity relationship, we demonstrate the value of diversity screening to complement the knowledge-based approach used in our previous ATAD2 work. We also exemplify tactics that can increase the chance of success when seeking new chemical starting points for novel and less-tractable targets.
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http://dx.doi.org/10.1021/acs.jmedchem.9b00673DOI Listing
August 2019

A Qualified Success: Discovery of a New Series of ATAD2 Bromodomain Inhibitors with a Novel Binding Mode Using High-Throughput Screening and Hit Qualification.

J Med Chem 2019 08 9;62(16):7506-7525. Epub 2019 Aug 9.

GlaxoSmithKline Tres Cantos , 28760 Tres Cantos , Madrid , Spain.

The bromodomain of ATAD2 has proved to be one of the least-tractable proteins within this target class. Here, we describe the discovery of a new class of inhibitors by high-throughput screening and show how the difficulties encountered in establishing a screening triage capable of finding progressible hits were overcome by data-driven optimization. Despite the prevalence of nonspecific hits and an exceptionally low progressible hit rate (0.001%), our optimized hit qualification strategy employing orthogonal biophysical methods enabled us to identify a single active series. The compounds have a novel ATAD2 binding mode with noncanonical features including the displacement of all conserved water molecules within the active site and a halogen-bonding interaction. In addition to reporting this new series and preliminary structure-activity relationship, we demonstrate the value of diversity screening to complement the knowledge-based approach used in our previous ATAD2 work. We also exemplify tactics that can increase the chance of success when seeking new chemical starting points for novel and less-tractable targets.
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http://dx.doi.org/10.1021/acs.jmedchem.9b00673DOI Listing
August 2019

Aiming to Miss a Moving Target: Bromo and Extra Terminal Domain (BET) Selectivity in Constrained ATAD2 Inhibitors.

J Med Chem 2018 09 18;61(18):8321-8336. Epub 2018 Sep 18.

Molecular Discovery Research, Cellzome GmbH , GlaxoSmithKline , Meyerhofstrasse 1 , 69117 Heidelberg , Germany.

ATAD2 is a cancer-associated protein whose bromodomain has been described as among the least druggable of its class. In our recent disclosure of the first chemical probe against this bromodomain, GSK8814 (6), we described the use of a conformationally constrained methoxy piperidine to gain selectivity over the BET bromodomains. Here we describe an orthogonal conformational restriction strategy of the piperidine ring to give potent and selective tropane inhibitors and show structural insights into why this was more challenging than expected. Greater understanding of why different rational approaches succeeded or failed should help in the future design of selectivity in the bromodomain family.
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http://dx.doi.org/10.1021/acs.jmedchem.8b00862DOI Listing
September 2018

Point-of-care diagnostic assay for the detection of Zika virus using the recombinase polymerase amplification method.

J Gen Virol 2018 08 13;99(8):1012-1026. Epub 2018 Jun 13.

Public Health England, National Infection Service, Microbiology Services Division, Porton Down, Salisbury, Wiltshire, SP4 0JG, UK.

The sudden and explosive expansion of Zika virus (ZIKV) from the African continent through Oceania and culminating in the outbreak in South America has highlighted the importance of new rapid point-of-care diagnostic tools for the control and prevention of transmission. ZIKV infection has devastating consequences, such as neurological congenital malformations in infants born to infected mothers and Guillain-Barré syndrome in adults. Additionally, its potential for transmission through vector bites, as well as from person to person through blood transfusions and sexual contact, are important considerations for prompt diagnosis. Recombinase polymerase amplification (RPA), an isothermal method, was developed as an alternative field-applicable assay to PCR. Here we report the development of a novel ZIKV real-time reverse transcriptase RPA (RT-RPA) assay capable of detecting a range of different ZIKV strains from a variety of geographical locations. The ZIKV RT-RPA was shown to be highly sensitive, being capable of detecting as few as five copies of target nucleic acid per reaction, and suitable for use with a battery-operated portable device. The ZIKV RT-RPA demonstrated 100 % specificity and 83 % sensitivity in clinical samples. Furthermore, we determined that the ZIKV RT-RPA is a versatile assay that can be applied to crude samples, such as saliva and serum, and can be used as a vector surveillance tool on crude mosquito homogenates. Therefore, the developed ZIKV RT-RPA is a useful diagnostic tool that can be transferred to a resource-limited location, eliminating the need for a specialized and sophisticated laboratory environment and highly trained staff.
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http://dx.doi.org/10.1099/jgv.0.001083DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6171711PMC
August 2018

A recombinase polymerase amplification assay for rapid detection of Crimean-Congo Haemorrhagic fever Virus infection.

PLoS Negl Trop Dis 2017 Oct 13;11(10):e0006013. Epub 2017 Oct 13.

National Infection Service, Public Health England, Porton Down, Salisbury, United Kingdom.

Background: Crimean-Congo Haemorrhagic fever Virus (CCHFV) is a rapidly emerging vector-borne pathogen and the cause of a virulent haemorrhagic fever affecting large parts of Europe, Africa, the Middle East and Asia.

Methodology/principle Findings: An isothermal recombinase polymerase amplification (RPA) assay was successfully developed for molecular detection of CCHFV. The assay showed rapid (under 10 minutes) detection of viral extracts/synthetic virus RNA of all 7 S-segment clades of CCHFV, with high target specificity. The assay was shown to tolerate the presence of inhibitors in crude preparations of mock field samples, indicating that this assay may be suitable for use in the field with minimal sample preparation. The CCHFV RPA was successfully used to screen and detect CCHFV positives from a panel of clinical samples from Tajikistan.

Conclusions/significance: The assay is a rapid, isothermal, simple-to-perform molecular diagnostic, which can be performed on a light, portable real-time detection device. It is ideally placed therefore for use as a field-diagnostic or in-low resource laboratories, for monitoring of CCHF outbreaks at the point-of-need, such as in remote rural regions in affected countries.
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http://dx.doi.org/10.1371/journal.pntd.0006013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5656326PMC
October 2017

Serological and Virological Evidence of Crimean-Congo Haemorrhagic Fever Virus Circulation in the Human Population of Borno State, Northeastern Nigeria.

PLoS Negl Trop Dis 2016 12 7;10(12):e0005126. Epub 2016 Dec 7.

National Infection Service, Public Health England, Salisbury, Wiltshire, United Kingdom.

Background: Despite several studies on the seroprevalence of antibodies against Crimean-Congo Haemorrhagic Fever virus (CCHFV) from humans and cattle in Nigeria, detailed investigation looking at IgG and IgM have not been reported. Additionally, there have been no confirmed cases of human CCHFV infection reported from Nigeria.

Principal Findings: Samples from sera (n = 1189) collected from four Local Government Areas in Borno State (Askira/Uba, Damboa, Jere and Maiduguri) were assessed for the presence of IgG and IgM antibodies. The positivity rates for IgG and IgM were 10.6% and 3.5%, respectively. Additionally, sera from undiagnosed febrile patients (n = 380) were assessed by RT-PCR assay for the presence of CCHFV RNA. One positive sample was characterised by further by next generation sequencing (NGS) resulting in complete S, M and L segment sequences.

Conclusions: This article provides evidence for the continued exposure of the human population of Nigeria to CCHFV. The genomic analysis provides the first published evidence of a human case of CCHFV in Nigeria and its phylogenetic context.
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http://dx.doi.org/10.1371/journal.pntd.0005126DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5142770PMC
December 2016

Antiviral Screening of Multiple Compounds against Ebola Virus.

Viruses 2016 10 27;8(11). Epub 2016 Oct 27.

Public Health England, Porton Down, Salisbury, Wiltshire SP4 0JG, UK.

In light of the recent outbreak of Ebola virus (EBOV) disease in West Africa, there have been renewed efforts to search for effective antiviral countermeasures. A range of compounds currently available with broad antimicrobial activity have been tested for activity against EBOV. Using live EBOV, eighteen candidate compounds were screened for antiviral activity in vitro. The compounds were selected on a rational basis because their mechanisms of action suggested that they had the potential to disrupt EBOV entry, replication or exit from cells or because they had displayed some antiviral activity against EBOV in previous tests. Nine compounds caused no reduction in viral replication despite cells remaining healthy, so they were excluded from further analysis (zidovudine; didanosine; stavudine; abacavir sulphate; entecavir; JB1a; Aimspro; celgosivir; and castanospermine). A second screen of the remaining compounds and the feasibility of appropriateness for in vivo testing removed six further compounds (ouabain; omeprazole; esomeprazole; Gleevec; D-LANA-14; and Tasigna). The three most promising compounds (17-DMAG; BGB324; and NCK-8) were further screened for in vivo activity in the guinea pig model of EBOV disease. Two of the compounds, BGB324 and NCK-8, showed some effect against lethal infection in vivo at the concentrations tested, which warrants further investigation. Further, these data add to the body of knowledge on the antiviral activities of multiple compounds against EBOV and indicate that the scientific community should invest more effort into the development of novel and specific antiviral compounds to treat Ebola virus disease.
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http://dx.doi.org/10.3390/v8110277DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5127007PMC
October 2016

Optimisation of a novel series of potent and orally bioavailable azanaphthyridine SYK inhibitors.

Bioorg Med Chem Lett 2016 10 23;26(19):4606-4612. Epub 2016 Aug 23.

AstraZeneca, Hodgkin Building, Chesterford Research Campus, Little Chesterford, Saffron Walden, Cambs. CB10 1XL, UK.

The optimisation of the azanaphthyridine series of Spleen Tyrosine Kinase inhibitors is described. The medicinal chemistry strategy was focused on optimising the human whole blood activity whilst achieving a sufficient margin over hERG activity. A good pharmacokinetic profile was achieved by modification of the pKa. Morpholine compound 32 is a potent SYK inhibitor showing moderate selectivity, good oral bioavailability and good efficacy in the rat Arthus model but demonstrated a genotoxic potential in the Ames assay.
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http://dx.doi.org/10.1016/j.bmcl.2016.08.070DOI Listing
October 2016

A Chemical Probe for the ATAD2 Bromodomain.

Angew Chem Int Ed Engl 2016 09 17;55(38):11382-6. Epub 2016 Aug 17.

GlaxoSmithKline, Gunnels Wood Road, Stevenage, SG1 2NY, UK.

ATAD2 is a cancer-associated protein whose bromodomain has been described as among the least druggable of that target class. Starting from a potent lead, permeability and selectivity were improved through a dual approach: 1) using CF2 as a sulfone bio-isostere to exploit the unique properties of fluorine, and 2) using 1,3-interactions to control the conformation of a piperidine ring. This resulted in the first reported low-nanomolar, selective and cell permeable chemical probe for ATAD2.
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http://dx.doi.org/10.1002/anie.201603928DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7314595PMC
September 2016

GSK6853, a Chemical Probe for Inhibition of the BRPF1 Bromodomain.

ACS Med Chem Lett 2016 Jun 9;7(6):552-7. Epub 2016 May 9.

Epinova Discovery Performance Unit, Quantitative Pharmacology, Experimental Medicine Unit, Flexible Discovery Unit, and Platform Technology and Science, GlaxoSmithKline , Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, U.K.

The BRPF (Bromodomain and PHD Finger-containing) protein family are important scaffolding proteins for assembly of MYST histone acetyltransferase complexes. A selective benzimidazolone BRPF1 inhibitor showing micromolar activity in a cellular target engagement assay was recently described. Herein, we report the optimization of this series leading to the identification of a superior BRPF1 inhibitor suitable for in vivo studies.
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http://dx.doi.org/10.1021/acsmedchemlett.6b00092DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4904261PMC
June 2016

A Susceptible Mouse Model for Zika Virus Infection.

PLoS Negl Trop Dis 2016 05 5;10(5):e0004658. Epub 2016 May 5.

National Infection Service, Public Health England, Porton Down, Salisbury, Wiltshire, United Kingdom.

Zika virus (ZIKV) is a mosquito-borne pathogen which has recently spread beyond Africa and into Pacific and South American regions. Despite first being detected in 1947, very little information is known about the virus, and its spread has been associated with increases in Guillain-Barre syndrome and microcephaly. There are currently no known vaccines or antivirals against ZIKV infection. Progress in assessing interventions will require the development of animal models to test efficacies; however, there are only limited reports on in vivo studies. The only susceptible murine models have involved intracerebral inoculations or juvenile animals, which do not replicate natural infection. Our report has studied the effect of ZIKV infection in type-I interferon receptor deficient (A129) mice and the parent strain (129Sv/Ev) after subcutaneous challenge in the lower leg to mimic a mosquito bite. A129 mice developed severe symptoms with widespread viral RNA detection in the blood, brain, spleen, liver and ovaries. Histological changes were also striking in these animals. 129Sv/Ev mice developed no clinical symptoms or histological changes, despite viral RNA being detectable in the blood, spleen and ovaries, albeit at lower levels than those seen in A129 mice. Our results identify A129 mice as being highly susceptible to ZIKV and thus A129 mice represent a suitable, and urgently required, small animal model for the testing of vaccines and antivirals.
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http://dx.doi.org/10.1371/journal.pntd.0004658DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4858159PMC
May 2016

Navigating CYP1A Induction and Arylhydrocarbon Receptor Agonism in Drug Discovery. A Case History with S1P1 Agonists.

J Med Chem 2015 Oct 1;58(20):8236-56. Epub 2015 Oct 1.

Immuno-Inflammation Therapy Area Unit, GlaxoSmithKline , Gunnels Wood Road, Stevenage, SG1 2NY, U.K.

This article describes the finding of substantial upregulation of mRNA and enzymes of the cytochrome P450 1A family during a lead optimization campaign for small molecule S1P1 agonists. Fold changes in mRNA up to 10,000-fold for CYP1A1 in vivo in rat and cynomolgus monkey and up to 45-fold for CYP1A1 and CYP1A2 in vitro in rat and human hepatocytes were observed. Challenges observed with correlating induction in vitro and induction in vivo resulted in the implementation of a short, 4 day in vivo screening study in the rat which successfully identified noninducers. Subtle structure-activity relationships in this series of S1P1 agonists are described extending beyond planarity and lipophilicity, and the impact and considerations of AhR and CYP1A induction in the context of drug development are discussed.
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http://dx.doi.org/10.1021/acs.jmedchem.5b01102DOI Listing
October 2015

Structure-Based Optimization of Naphthyridones into Potent ATAD2 Bromodomain Inhibitors.

J Med Chem 2015 Aug 31;58(15):6151-78. Epub 2015 Jul 31.

∥Cellzome GmbH, Molecular Discovery Research, GlaxoSmithKline, Meyerhofstrasse 1, 69117 Heidelberg, Germany.

ATAD2 is a bromodomain-containing protein whose overexpression is linked to poor outcomes in a number of different cancer types. To date, no potent and selective inhibitors of the bromodomain have been reported. This article describes the structure-based optimization of a series of naphthyridones from micromolar leads with no selectivity over the BET bromodomains to inhibitors with sub-100 nM ATAD2 potency and 100-fold BET selectivity.
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http://dx.doi.org/10.1021/acs.jmedchem.5b00773DOI Listing
August 2015

Fragment-Based Discovery of Low-Micromolar ATAD2 Bromodomain Inhibitors.

J Med Chem 2015 Jul 9;58(14):5649-73. Epub 2015 Jul 9.

∥Drug Metabolism and Pharmacokinetics (DMPK), GlaxoSmithKline, Park Road, Ware, Hertfordshire SG12 0DP, United Kingdom.

Overexpression of ATAD2 (ATPase family, AAA domain containing 2) has been linked to disease severity and progression in a wide range of cancers, and is implicated in the regulation of several drivers of cancer growth. Little is known of the dependence of these effects upon the ATAD2 bromodomain, which has been categorized as among the least tractable of its class. The absence of any potent, selective inhibitors limits clear understanding of the therapeutic potential of the bromodomain. Here, we describe the discovery of a hit from a fragment-based targeted array. Optimization of this produced the first known micromolar inhibitors of the ATAD2 bromodomain.
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http://dx.doi.org/10.1021/acs.jmedchem.5b00772DOI Listing
July 2015

1,3-Dimethyl Benzimidazolones Are Potent, Selective Inhibitors of the BRPF1 Bromodomain.

ACS Med Chem Lett 2014 Nov 10;5(11):1190-5. Epub 2014 Sep 10.

Epinova Discovery Performance Unit and Molecular Discovery Research, GlaxoSmithKline , Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, U.K.

The BRPF (bromodomain and PHD finger-containing) protein family are important scaffolding proteins for assembly of MYST histone acetyltransferase complexes. Here, we report the discovery, binding mode, and structure-activity relationship (SAR) of the first potent, selective series of inhibitors of the BRPF1 bromodomain.
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http://dx.doi.org/10.1021/ml5002932DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4233354PMC
November 2014

Discovery of GSK143, a highly potent, selective and orally efficacious spleen tyrosine kinase inhibitor.

Bioorg Med Chem Lett 2011 Oct 12;21(20):6188-94. Epub 2011 Aug 12.

GlaxoSmithKline R&D, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, UK.

The lead optimisation of the diaminopyrimidine carboxamide series of spleen tyrosine kinase inhibitors is described. The medicinal chemistry strategy was focused on optimising the human whole blood activity whilst achieving a sufficient margin over liability kinases and hERG activity. GSK143 is a potent and highly selective SYK inhibitor showing good efficacy in the rat Arthus model.
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http://dx.doi.org/10.1016/j.bmcl.2011.07.082DOI Listing
October 2011

The role of iron uptake in pathogenicity and symbiosis in Photorhabdus luminescens TT01.

BMC Microbiol 2010 Jun 22;10:177. Epub 2010 Jun 22.

Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK.

Background: Photorhabdus are Gram negative bacteria that are pathogenic to insect larvae whilst also having a mutualistic interaction with nematodes from the family Heterorhabditis. Iron is an essential nutrient and bacteria have different mechanisms for obtaining both the ferrous (Fe2+) and ferric (Fe3+) forms of this metal from their environments. In this study we were interested in analyzing the role of Fe3+ and Fe2+ iron uptake systems in the ability of Photorhabdus to interact with its invertebrate hosts.

Results: We constructed targeted deletion mutants of exbD, feoABC and yfeABCD in P. luminescens TT01. The exbD mutant was predicted to be crippled in its ability to obtain Fe3+ and we show that this mutant does not grow well in iron-limited media. We also show that this mutant was avirulent to the insect but was unaffected in its symbiotic interaction with Heterorhabditis. Furthermore we show that a mutation in feoABC (encoding a predicted Fe2+ permease) was unaffected in both virulence and symbiosis whilst the divalent cation transporter encoded by yfeABCD is required for virulence in the Tobacco Hornworm, Manduca sexta (Lepidoptera) but not in the Greater Wax Moth, Galleria mellonella (Lepidoptera). Moreover the Yfe transporter also appears to have a role during colonization of the IJ stage of the nematode.

Conclusion: In this study we show that iron uptake (via the TonB complex and the Yfe transporter) is important for the virulence of P. luminescens to insect larvae. Moreover this study also reveals that the Yfe transporter appears to be involved in Mn2+-uptake during growth in the gut lumen of the IJ nematode. Therefore, the Yfe transporter in P. luminescens TT01 is important during colonization of both the insect and nematode and, moreover, the metal ion transported by this pathway is host-dependent.
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http://dx.doi.org/10.1186/1471-2180-10-177DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2905363PMC
June 2010

Development of CXCR3 antagonists. Part 4: discovery of 2-amino-(4-tropinyl)quinolines.

Bioorg Med Chem Lett 2008 Jan 28;18(2):629-33. Epub 2007 Nov 28.

UCB Inflammation Discovery, Granta Park, Great Abington, Cambridge CB21 6GS, United Kingdom.

The synthesis and biological evaluation of a novel series of 2-aminoquinoline substituted piperidines and tropanes incorporating a homotropene moiety is herein described. The series exhibits potent antagonism of the CXCR3 receptor and superior physicochemical properties. Compound 24d was found to be orally bioavailable, and PK/PD studies suggested it as a suitable tool for studying the role of CXCR3 in models of disease.
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http://dx.doi.org/10.1016/j.bmcl.2007.11.075DOI Listing
January 2008