ORCID Profile
0000-0002-3549-4309
Current Organisations
Universityhospital Tübingen
,
University of Oxford
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Publisher: American Society for Microbiology
Date: 2011
DOI: 10.1128/JVI.01826-10
Abstract: The evolution of dengue viruses has resulted in four antigenically similar yet distinct serotypes. Infection with one serotype likely elicits lifelong immunity to that serotype, but generally not against the other three. Secondary or sequential infections are common, as multiple viral serotypes frequently cocirculate. Dengue infection, although frequently mild, can lead to dengue hemorrhagic fever (DHF) which can be life threatening. DHF is more common in secondary dengue infections, implying a role for the adaptive immune response in the disease. There is currently much effort toward the design and implementation of a dengue vaccine but these efforts are made more difficult by the challenge of inducing durable neutralizing immunity to all four viruses. Domain 3 of the dengue virus envelope protein (ED3) has been suggested as one such candidate because it contains neutralizing epitopes and it was originally thought that relatively few cross-reactive antibodies are directed to this domain. In this study, we performed a detailed analysis of the anti-ED3 response in a cohort of patients suffering either primary or secondary dengue infections. The results show dramatic evidence of original antigenic sin in secondary infections both in terms of binding and enhancement activity. This has important implications for dengue vaccine design because heterologous boosting is likely to maintain the immunological footprint of the first vaccination. On the basis of these findings, we propose a simple in vitro enzyme-linked immunosorbent assay (ELISA) to diagnose the original dengue infection in secondary dengue cases.
Publisher: Springer Science and Business Media LLC
Date: 09-11-2022
DOI: 10.1038/S41467-022-34415-1
Abstract: Dengue virus infection can cause dengue hemorrhagic fever (DHF). Dengue NS1 is multifunctional. The intracellular dimeric NS1 (iNS1) forms part of the viral replication complex. Previous studies suggest the extracellular secreted NS1 (sNS1), which is a major factor contributing to DHF, exists as hexamers. The structure of the iNS1 is well-characterised but not that of sNS1. Here we show by cryoEM that the recombinant sNS1 exists in multiple oligomeric states: the tetrameric (stable and loose conformation) and hexameric structures. Stability of the stable and loose tetramers is determined by the conformation of their N-terminal domain – elongated β-sheet or β-roll. Binding of an anti-NS1 Fab breaks the loose tetrameric and hexameric sNS1 into dimers, whereas the stable tetramer remains largely unbound. Our results show detailed quaternary organization of different oligomeric states of sNS1 and will contribute towards the design of dengue therapeutics.
Publisher: Elsevier BV
Date: 09-2021
Publisher: Wiley
Date: 07-2008
DOI: 10.1002/CNCR.23528
Abstract: The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) death receptor, DR5, mediates proapoptotic signals and is implicated in the pathogenesis of many neoplasms including nonsmall-cell lung cancer (NSCLC). In this study, immunohistochemical expression of DR5 was examined in 146 cases of stage I and II NSCLC as well as neoplastic precursor lesions and regional lymph node metastases using tissue microarrays. High DR5 expression was observed in 67.1% of primary NSCLC, 55.6% of bronchial squamous carcinoma in situ, 40% of squamous metaplasia, as well as 76.5% of lymph node metastases. In all of these lesions, DR5 expression was significantly higher than in normal bronchial epithelium. Increased expression of DR5 correlated with poorly differentiated tumors and was inversely correlated with bronchioloalveolar carcinomas. There was no correlation with other clinicopathologic variables. A significant association was found between high DR5 expression and reduced overall survival in univariate analysis. Among smokers, high DR5 and tumor stage were independent predictors of reduced disease-free survival in multivariate analysis, however, DR5 was not an independent prognostic marker among the entire cohort of NSCLC. These findings suggest that DR5 plays a role in the development of early-stage NSCLC and the high levels of DR5 expression suggest that these tumors may be susceptible to novel anticancer agents targeting the DR5 receptor and may improve patient survival, particularly for patients who are smokers.
Publisher: Public Library of Science (PLoS)
Date: 10-07-2017
Publisher: Elsevier BV
Date: 08-2017
Publisher: Elsevier BV
Date: 10-2006
DOI: 10.1016/J.HUMPATH.2006.04.026
Abstract: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in melanoma by interaction with death receptors TRAIL-R1 (DR4) or TRAIL-R2 (DR5) on melanoma cells or resists apoptosis by interaction with decoy receptors TRAIL-R3 (DcR1) or TRAIL-R4 (DcR2). Studies on cell lines suggest that there is a wide variation in TRAIL death receptor expression however, their expression on excised human melanoma is not well documented. In view of this, we studied death receptor expression on melanomas using monoclonal antibodies specific for these receptors. Immunohistochemical staining for DR4, DR5, and DcR1/DcR2 was performed on formalin-fixed paraffin-embedded sections of 100 cases of primary melanoma, metastatic melanoma, and benign nevi. Percentage expressions of DR4 versus DR5 in benign nevi, primary melanoma, and melanoma metastases were 40% versus 90%, 69% versus 98%, and 55% versus 66%, respectively. There were significant differences in the mean percentage of DR5-positive cells between different groups of melanocytic lesions. Percent expression was higher in thin (< or =1.0 mm) compared with thick primary melanoma (88.9% versus 66.9%), and expression was less in subcutaneous metastases (49%) and lymph node metastases (30.6%) (P < .005). Expression was also higher in compound nevi (57%) than dysplastic nevi (49%). DcR1/DcR2 was found in 75% of benign nevi, 62% of primary melanomas, and 74% melanoma metastases. The results showed a wide variation in the expression of death receptors for TRAIL between and within primary and metastatic melanoma and a decreased expression on the thick primary melanoma and metastatic melanoma. This suggests that melanoma may not respond to treatment with TRAIL unless given with agents that increase the expression of TRAIL death receptors.
Publisher: Springer Science and Business Media LLC
Date: 21-07-2021
DOI: 10.1038/S41564-021-00947-3
Abstract: We report that in a cohort of 45,965 adults, who were receiving either the ChAdOx1 or the BNT162b2 SARS-CoV-2 vaccines, in those who had no prior infection with SARS-CoV-2, seroconversion rates and quantitative antibody levels after a single dose were lower in older in iduals, especially in those aged years. Two vaccine doses achieved high responses across all ages. Antibody levels increased more slowly and to lower levels with a single dose of ChAdOx1 compared with a single dose of BNT162b2, but waned following a single dose of BNT162b2 in older in iduals. In descriptive latent class models, we identified four responder subgroups, including a ‘low responder’ group that more commonly consisted of people aged years, males and in iduals with long-term health conditions. Given our findings, we propose that available vaccines should be prioritized for those not previously infected and that second doses should be prioritized for in iduals aged years. Further data are needed to better understand the extent to which quantitative antibody responses are associated with vaccine-mediated protection.
Publisher: Elsevier BV
Date: 08-2020
Publisher: Springer Science and Business Media LLC
Date: 29-10-2021
DOI: 10.1038/S41467-021-26479-2
Abstract: Understanding the trajectory, duration, and determinants of antibody responses after SARS-CoV-2 infection can inform subsequent protection and risk of reinfection, however large-scale representative studies are limited. Here we estimated antibody response after SARS-CoV-2 infection in the general population using representative data from 7,256 United Kingdom COVID-19 infection survey participants who had positive swab SARS-CoV-2 PCR tests from 26-April-2020 to 14-June-2021. A latent class model classified 24% of participants as ‘non-responders’ not developing anti-spike antibodies, who were older, had higher SARS-CoV-2 cycle threshold values during infection (i.e. lower viral burden), and less frequently reported any symptoms. Among those who seroconverted, using Bayesian linear mixed models, the estimated anti-spike IgG peak level was 7.3-fold higher than the level previously associated with 50% protection against reinfection, with higher peak levels in older participants and those of non-white ethnicity. The estimated anti-spike IgG half-life was 184 days, being longer in females and those of white ethnicity. We estimated antibody levels associated with protection against reinfection likely last 1.5-2 years on average, with levels associated with protection from severe infection present for several years. These estimates could inform planning for vaccination booster strategies.
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 03-2018
Publisher: Elsevier BV
Date: 03-2021
Publisher: Oxford University Press (OUP)
Date: 26-05-2016
Publisher: Elsevier BV
Date: 2020
Publisher: Elsevier BV
Date: 03-2022
Publisher: Cold Spring Harbor Laboratory
Date: 09-06-2021
DOI: 10.1101/2021.06.08.447308
Abstract: There is an ongoing global effort to design, manufacture, and clinically assess vaccines against SARS-CoV-2. Over the course of the ongoing pandemic a number of new SARS-CoV-2 virus isolates or variants of concern (VoC) have been identified containing mutations in key proteins. In this study we describe the generation and preclinical assessment of a ChAdOx1-vectored vaccine (AZD2816) which expresses the spike protein of the Beta VoC (B.1.351). We demonstrate that AZD2816 is immunogenic after a single dose. When AZD2816 is used as a booster dose in animals primed with a vaccine encoding the original spike protein (ChAdOx1 nCoV-19/ [AZD1222]), high titre binding and neutralising antibodies against Beta (B.1.351), Gamma (P.1) and Delta (B.1.617.2) are induced. In addition, a strong and polyfunctional T cell response was measured in these booster regimens. These data support the ongoing clinical development and testing of this new variant vaccine.
Publisher: Research Square Platform LLC
Date: 27-07-2021
DOI: 10.21203/RS.3.RS-734011/V1
Abstract: NP 105-113 -B*07:02 specific CD8 + T-cell responses are considered among the most dominant in SARS-CoV-2-infected in iduals. We found strong association of this response with mild disease. Analysis of NP 105-113 -B*07:02 specific T-cell clones and single cell sequencing were performed concurrently, with functional avidity and anti-viral efficacy assessed using an in vitro SARS-CoV-2 infection system, and were correlated with TCR usage, transcriptome signature, and disease severity (acute N=77, convalescent N=52). We demonstrated a beneficial association of NP 105-113 -B*07:02 specific T-cells in COVID-19 disease progression, linked with expansion of T-cell precursors, high functional avidity and anti-viral effector function. Broad immune memory pools were narrowed post-infection but NP 105-113 -B*07:02 specific T-cells were maintained 6 months after infection with preserved anti-viral efficacy to the SARS-CoV-2 Victoria strain, as well as new Alpha, Beta and Gamma variants. Our data shows that NP 105-113 -B*07:02 specific T-cell responses associate with mild disease and high anti-viral efficacy, pointing to inclusion for future vaccine design.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Springer Science and Business Media LLC
Date: 19-06-2020
DOI: 10.1038/S41467-020-16925-Y
Abstract: Previous flavivirus (dengue and Zika viruses) studies showed largely spherical particles either with smooth or bumpy surfaces. Here, we demonstrate flavivirus particles have high structural plasticity by the induction of a non-spherical morphology at elevated temperatures: the club-shaped particle (clubSP), which contains a cylindrical tail and a disc-like head. Complex formation of DENV and ZIKV with Fab C10 stabilize the viruses allowing cryoEM structural determination to ~10 Å resolution. The caterpillar-shaped (catSP) Fab C10:ZIKV complex shows Fabs locking the E protein raft structure containing three E dimers. However, compared to the original spherical structure, the rafts have rotated relative to each other. The helical tail structure of Fab C10:DENV3 clubSP showed although the Fab locked an E protein dimer, the dimers have shifted laterally. Morphological ersity, including clubSP and the previously identified bumpy and smooth-surfaced spherical particles, may help flavivirus survival and immune evasion.
Publisher: Oxford University Press (OUP)
Date: 29-06-2017
DOI: 10.1093/CID/CIX567
Publisher: Elsevier BV
Date: 02-2015
Publisher: Public Library of Science (PLoS)
Date: 12-12-2013
Publisher: Springer Science and Business Media LLC
Date: 12-2021
DOI: 10.1038/S41590-021-01084-Z
Abstract: NP 105–113 -B*07:02-specific CD8 + T cell responses are considered among the most dominant in SARS-CoV-2-infected in iduals. We found strong association of this response with mild disease. Analysis of NP 105–113 -B*07:02-specific T cell clones and single-cell sequencing were performed concurrently, with functional avidity and antiviral efficacy assessed using an in vitro SARS-CoV-2 infection system, and were correlated with T cell receptor usage, transcriptome signature and disease severity (acute n = 77, convalescent n = 52). We demonstrated a beneficial association of NP 105–113 -B*07:02-specific T cells in COVID-19 disease progression, linked with expansion of T cell precursors, high functional avidity and antiviral effector function. Broad immune memory pools were narrowed postinfection but NP 105–113 -B*07:02-specific T cells were maintained 6 months after infection with preserved antiviral efficacy to the SARS-CoV-2 Victoria strain, as well as Alpha, Beta, Gamma and Delta variants. Our data show that NP 105–113 -B*07:02-specific T cell responses associate with mild disease and high antiviral efficacy, pointing to inclusion for future vaccine design.
Publisher: Springer Science and Business Media LLC
Date: 17-12-2020
Publisher: Elsevier BV
Date: 12-2020
Publisher: Massachusetts Medical Society
Date: 30-12-2021
DOI: 10.1056/NEJMC2103227
Publisher: Springer Science and Business Media LLC
Date: 10-07-2023
DOI: 10.1038/S41593-023-01359-8
Abstract: The Dominantly Inherited Alzheimer Network (DIAN) is an international collaboration studying autosomal dominant Alzheimer disease (ADAD). ADAD arises from mutations occurring in three genes. Offspring from ADAD families have a 50% chance of inheriting their familial mutation, so non-carrier siblings can be recruited for comparisons in case–control studies. The age of onset in ADAD is highly predictable within families, allowing researchers to estimate an in idual’s point in the disease trajectory. These characteristics allow candidate AD biomarker measurements to be reliably mapped during the preclinical phase. Although ADAD represents a small proportion of AD cases, understanding neuroimaging-based changes that occur during the preclinical period may provide insight into early disease stages of ‘sporadic’ AD also. Additionally, this study provides rich data for research in healthy aging through inclusion of the non-carrier controls. Here we introduce the neuroimaging dataset collected and describe how this resource can be used by a range of researchers.
Publisher: Springer Science and Business Media LLC
Date: 17-12-2020
Publisher: American Society for Microbiology
Date: 15-01-2010
DOI: 10.1128/JVI.01662-09
Abstract: The genome of the severe acute respiratory syndrome-associated coronavirus (SARS-CoV) contains eight open reading frames (ORFs) that encode novel proteins. These accessory proteins are dispensable for in vitro and in vivo replication and thus may be important for other aspects of virus-host interactions. We investigated the functions of the largest of the accessory proteins, the ORF 3a protein, using a 3a-deficient strain of SARS-CoV. Cell death of Vero cells after infection with SARS-CoV was reduced upon deletion of ORF 3a. Electron microscopy of infected cells revealed a role for ORF 3a in SARS-CoV induced vesicle formation, a prominent feature of cells from SARS patients. In addition, we report that ORF 3a is both necessary and sufficient for SARS-CoV-induced Golgi fragmentation and that the 3a protein accumulates and localizes to vesicles containing markers for late endosomes. Finally, overexpression of ADP-ribosylation factor 1 (Arf1), a small GTPase essential for the maintenance of the Golgi apparatus, restored Golgi morphology during infection. These results establish an important role for ORF 3a in SARS-CoV-induced cell death, Golgi fragmentation, and the accumulation of intracellular vesicles.
Publisher: Springer Science and Business Media LLC
Date: 08-04-2014
Abstract: Dengue is one of the most important emerging viral diseases globally. The majority of symptomatic infections result in a relatively benign disease course. However, a small proportion of patients develop severe clinical manifestations, including bleeding, organ impairment, and endothelial dysfunction with increased capillary permeability causing hypovolaemic shock that can lead to cardiovascular collapse. Evidence is increasing that dengue can also cause myocardial impairment, arrhythmias and, occasionally, fulminant myocarditis. No antiviral agents or vaccines are licensed for dengue, and treatment remains supportive with judicious fluid replacement for patients with severe disease. Defining the role of cardiac dysfunction in the haemodynamic compromise of severe dengue has potentially important management implications. In this Review, we will outline the current understanding of the cardiovascular manifestations of dengue, including myocardial and vascular involvement, and conclude with a discussion of the available therapeutic options and potential future research directions.
Publisher: Springer Science and Business Media LLC
Date: 15-12-2014
DOI: 10.1038/NI.3058
Publisher: Springer Science and Business Media LLC
Date: 25-09-2017
DOI: 10.1038/NI.3850
Abstract: Adaptive immune responses protect against infection with dengue virus (DENV), yet cross-reactivity with distinct serotypes can precipitate life-threatening clinical disease. We found that clonotypes expressing the T cell antigen receptor (TCR) β-chain variable region 11 (TRBV11-2) were 'preferentially' activated and mobilized within immunodominant human-leukocyte-antigen-(HLA)-A*11:01-restricted CD8
Publisher: Springer Science and Business Media LLC
Date: 14-02-2022
DOI: 10.1038/S41591-022-01721-6
Abstract: Antibody responses are an important part of immunity after Coronavirus Disease 2019 (COVID-19) vaccination. However, antibody trajectories and the associated duration of protection after a second vaccine dose remain unclear. In this study, we investigated anti-spike IgG antibody responses and correlates of protection after second doses of ChAdOx1 or BNT162b2 vaccines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the United Kingdom general population. In 222,493 in iduals, we found significant boosting of anti-spike IgG by the second doses of both vaccines in all ages and using different dosing intervals, including the 3-week interval for BNT162b2. After second vaccination, BNT162b2 generated higher peak levels than ChAdOX1. Older in iduals and males had lower peak levels with BNT162b2 but not ChAdOx1, whereas declines were similar across ages and sexes with ChAdOX1 or BNT162b2. Prior infection significantly increased antibody peak level and half-life with both vaccines. Anti-spike IgG levels were associated with protection from infection after vaccination and, to an even greater degree, after prior infection. At least 67% protection against infection was estimated to last for 2–3 months after two ChAdOx1 doses, for 5–8 months after two BNT162b2 doses in those without prior infection and for 1–2 years for those unvaccinated after natural infection. A third booster dose might be needed, prioritized to ChAdOx1 recipients and those more clinically vulnerable.
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 03-2022
Publisher: Springer Science and Business Media LLC
Date: 06-05-2021
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Gavin Screaton.