Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
96
result(s) for
"Ritter, Thomas G"
Sort by:
Emerging variants develop total escape from potent monoclonal antibodies induced by BA.4/5 infection
by
Dijokaite-Guraliuc, Aiste
,
Duyvesteyn, Helen M. E.
,
Selvaraj, Muneeswaran
in
13/1
,
631/250/2152/2153/1291
,
631/326/596/4130
2024
The rapid evolution of SARS-CoV-2 is driven in part by a need to evade the antibody response in the face of high levels of immunity. Here, we isolate spike (S) binding monoclonal antibodies (mAbs) from vaccinees who suffered vaccine break-through infections with Omicron sub lineages BA.4 or BA.5. Twenty eight potent antibodies are isolated and characterised functionally, and in some cases structurally. Since the emergence of BA.4/5, SARS-CoV-2 has continued to accrue mutations in the S protein, to understand this we characterize neutralization of a large panel of variants and demonstrate a steady attrition of neutralization by the panel of BA.4/5 mAbs culminating in total loss of function with recent XBB.1.5.70 variants containing the so-called ‘FLip’ mutations at positions 455 and 456. Interestingly, activity of some mAbs is regained on the recently reported variant BA.2.86.
Many emerging SARS-CoV-2 variants partially escape the humoral immune response. Here, Liu et al. characterize 28 antibodies from BA.4/5 breakthrough infections and find attrition of neutralization and complete loss of function for variants with Spike mutations at positions 455 and 456.
Journal Article
Antibody Status and Incidence of SARS-CoV-2 Infection in Health Care Workers
2021
In a longitudinal study of seropositive and seronegative health care workers undergoing asymptomatic and symptomatic SARS-CoV-2 testing, the presence of anti-spike or anti-nucleocapsid IgG antibodies was associated with a substantially reduced risk of SARS-CoV-2 reinfection in the ensuing 6 months.
Journal Article
Divergent trajectories of antiviral memory after SARS-CoV-2 infection
2022
The trajectories of acquired immunity to severe acute respiratory syndrome coronavirus 2 infection are not fully understood. We present a detailed longitudinal cohort study of UK healthcare workers prior to vaccination, presenting April-June 2020 with asymptomatic or symptomatic infection. Here we show a highly variable range of responses, some of which (T cell interferon-gamma ELISpot, N-specific antibody) wane over time, while others (spike-specific antibody, B cell memory ELISpot) are stable. We use integrative analysis and a machine-learning approach (SIMON - Sequential Iterative Modeling OverNight) to explore this heterogeneity. We identify a subgroup of participants with higher antibody responses and interferon-gamma ELISpot T cell responses, and a robust trajectory for longer term immunity associates with higher levels of neutralising antibodies against the infecting (Victoria) strain and also against variants B.1.1.7 (alpha) and B.1.351 (beta). These variable trajectories following early priming may define subsequent protection from severe disease from novel variants.
The engagement of immunological memory is a key component to the protective anti-SARS-CoV-2 B and T cell responses. Here the authors assess the B and T cells of a cohort of UK healthcare workers in response to infection and longitudinally track the compartment showing distinct trajectories following early priming.
Journal Article
Further antibody escape by Omicron BA.4 and BA.5 from vaccine and BA.1 serum
2022
The Omicron lineage of SARS-CoV-2, first described in November 2021, spread rapidly to become globally dominant and has split into a number of sub-lineages. BA.1 dominated the initial wave but has been replaced by BA.2 in many countries. Recent sequencing from South Africa’s Gauteng region uncovered two new sub-lineages, BA.4 and BA.5 which are taking over locally, driving a new wave. BA.4 and BA.5 contain identical spike sequences and, although closely related to BA.2, contain further mutations in the receptor binding domain of spike. Here, we study the neutralization of BA.4/5 using a range of vaccine and naturally immune serum and panels of monoclonal antibodies. BA.4/5 shows reduced neutralization by serum from triple AstraZeneca or Pfizer vaccinated individuals compared to BA.1 and BA.2. Furthermore, using serum from BA.1 vaccine breakthrough infections there are likewise, significant reductions in the neutralization of BA.4/5, raising the possibility of repeat Omicron infections.
Hydrochlorothiazide and Prevention of Kidney-Stone Recurrence
by
Bonny, Olivier
,
Venzin, Reto M.
,
Christe, Andreas
in
Calcium phosphates
,
Calculi
,
Clinical Medicine
2023
In a trial involving patients with recurrent kidney stones who received once-daily 12.5-mg, 25-mg, or 50-mg doses of hydrochlorothiazide or placebo, the incidence of stone recurrence was similar in all groups.
Journal Article
TTK inhibition radiosensitizes basal-like breast cancer through impaired homologous recombination
by
Merajver, Sofia
,
Chandler, Benjamin C.
,
Pesch, Andrea M.
in
Biochemistry
,
Biomedical research
,
Biotechnology
2020
Increased rates of locoregional recurrence are observed in patients with basal-like breast cancer (BC) despite the use of radiation therapy (RT); therefore, approaches that result in radiosensitization of basal-like BC are critically needed. Using patients' tumor gene expression data from 4 independent data sets, we correlated gene expression with recurrence to find genes significantly correlated with early recurrence after RT. The highest-ranked gene, TTK, was most highly expressed in basal-like BC across multiple data sets. Inhibition of TTK by both genetic and pharmacologic methods enhanced radiosensitivity in multiple basal-like cell lines. Radiosensitivity was mediated, at least in part, through persistent DNA damage after treatment with TTK inhibition and RT. Inhibition of TTK impaired homologous recombination (HR) and repair efficiency, but not nonhomologous end-joining, and decreased the formation of Rad51 foci. Reintroduction of wild-type TTK rescued both radioresistance and HR repair efficiency after TTK knockdown; however, reintroduction of kinase-dead TTK did not. In vivo, TTK inhibition combined with RT led to a significant decrease in tumor growth in both heterotopic and orthotopic, including patient-derived xenograft, BC models. These data support the rationale for clinical development of TTK inhibition as a radiosensitizing strategy for patients with basal-like BC, and efforts toward this end are currently underway.
Journal Article
The subcellular arrangement of alpha-synuclein proteoforms in the Parkinson’s disease brain as revealed by multicolor STED microscopy
2021
Various post-translationally modified (PTM) proteoforms of alpha-synuclein (aSyn)—including C-terminally truncated (CTT) and Serine 129 phosphorylated (Ser129-p) aSyn—accumulate in Lewy bodies (LBs) in different regions of the Parkinson’s disease (PD) brain. Insight into the distribution of these proteoforms within LBs and subcellular compartments may aid in understanding the orchestration of Lewy pathology in PD. We applied epitope-specific antibodies against CTT and Ser129-p aSyn proteoforms and different aSyn domains in immunohistochemical multiple labelings on post-mortem brain tissue from PD patients and non-neurological, aged controls, which were scanned using high-resolution 3D multicolor confocal and stimulated emission depletion (STED) microscopy. Our multiple labeling setup highlighted a consistent onion skin-type 3D architecture in mature nigral LBs in which an intricate and structured-appearing framework of Ser129-p aSyn and cytoskeletal elements encapsulates a core enriched in CTT aSyn species. By label-free CARS microscopy we found that enrichments of proteins and lipids were mainly localized to the central portion of nigral aSyn-immunopositive (aSyn+) inclusions. Outside LBs, we observed that 122CTT aSyn+ punctae localized at mitochondrial membranes in the cytoplasm of neurons in PD and control brains, suggesting a physiological role for 122CTT aSyn outside of LBs. In contrast, very limited to no Ser129-p aSyn immunoreactivity was observed in brains of non-neurological controls, while the alignment of Ser129-p aSyn in a neuronal cytoplasmic network was characteristic for brains with (incidental) LB disease. Interestingly, Ser129-p aSyn+ network profiles were not only observed in neurons containing LBs but also in neurons without LBs particularly in donors at early disease stage, pointing towards a possible subcellular pathological phenotype preceding LB formation. Together, our high-resolution and 3D multicolor microscopy observations in the post-mortem human brain provide insights into potential mechanisms underlying a regulated LB morphogenesis.
Journal Article
Performance characteristics of five immunoassays for SARS-CoV-2: a head-to-head benchmark comparison
by
Hatch, Stephanie B.
,
Dunachie, Susanna J
,
Coker, Jesse
in
Analysis
,
Antibodies
,
Antibodies, Viral - blood
2020
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic in 2020. Testing is crucial for mitigating public health and economic effects. Serology is considered key to population-level surveillance and potentially individual-level risk assessment. However, immunoassay performance has not been compared on large, identical sample sets. We aimed to investigate the performance of four high-throughput commercial SARS-CoV-2 antibody immunoassays and a novel 384-well ELISA.
We did a head-to-head assessment of SARS-CoV-2 IgG assay (Abbott, Chicago, IL, USA), LIAISON SARS-CoV-2 S1/S2 IgG assay (DiaSorin, Saluggia, Italy), Elecsys Anti-SARS-CoV-2 assay (Roche, Basel, Switzerland), SARS-CoV-2 Total assay (Siemens, Munich, Germany), and a novel 384-well ELISA (the Oxford immunoassay). We derived sensitivity and specificity from 976 pre-pandemic blood samples (collected between Sept 4, 2014, and Oct 4, 2016) and 536 blood samples from patients with laboratory-confirmed SARS-CoV-2 infection, collected at least 20 days post symptom onset (collected between Feb 1, 2020, and May 31, 2020). Receiver operating characteristic (ROC) curves were used to assess assay thresholds.
At the manufacturers' thresholds, for the Abbott assay sensitivity was 92·7% (95% CI 90·2–94·8) and specificity was 99·9% (99·4–100%); for the DiaSorin assay sensitivity was 96·2% (94·2–97·7) and specificity was 98·9% (98·0–99·4); for the Oxford immunoassay sensitivity was 99·1% (97·8–99·7) and specificity was 99·0% (98·1–99·5); for the Roche assay sensitivity was 97·2% (95·4–98·4) and specificity was 99·8% (99·3–100); and for the Siemens assay sensitivity was 98·1% (96·6–99·1) and specificity was 99·9% (99·4–100%). All assays achieved a sensitivity of at least 98% with thresholds optimised to achieve a specificity of at least 98% on samples taken 30 days or more post symptom onset.
Four commercial, widely available assays and a scalable 384-well ELISA can be used for SARS-CoV-2 serological testing to achieve sensitivity and specificity of at least 98%. The Siemens assay and Oxford immunoassay achieved these metrics without further optimisation. This benchmark study in immunoassay assessment should enable refinements of testing strategies and the best use of serological testing resource to benefit individuals and population health.
Public Health England and UK National Institute for Health Research.
Journal Article
A quantum liquid of magnetic octupoles on the pyrochlore lattice
2020
Spin liquids are highly correlated yet disordered states formed by the entanglement of magnetic dipoles
1
. Theories define such states using gauge fields and deconfined quasiparticle excitations that emerge from a local constraint governing the ground state of a frustrated magnet. For example, the ‘2-in–2-out’ ice rule for dipole moments on a tetrahedron can lead to a quantum spin ice
2
–
4
in rare-earth pyrochlores. However,
f
-electron ions often carry multipole degrees of freedom of higher rank than dipoles, leading to intriguing behaviours and ‘hidden’ orders
5
,
6
. Here we show that the correlated ground state of a Ce
3+
-based pyrochlore, Ce
2
Sn
2
O
7
, is a quantum liquid of magnetic octupoles. Our neutron scattering results are consistent with a fluid-like state where degrees of freedom have a more complex magnetization density than that of magnetic dipoles. The nature and strength of the octupole–octupole couplings, together with the existence of a continuum of excitations attributed to spinons, provides further evidence for a quantum ice of octupoles governed by a ‘2-plus–2-minus’ rule
7
,
8
. Our work identifies Ce
2
Sn
2
O
7
as a unique example of frustrated multipoles forming a ‘hidden’ topological order, thus generalizing observations on quantum spin liquids to multipolar phases that can support novel types of emergent fields and excitations.
A detailed neutron-scattering study reveals a quantum spin liquid behaviour in Ce
2
Sn
2
O
7
originating from its higher-order magnetic multipolar moments acting on the geometrically frustrated pyrochlore lattice.
Journal Article
Escitalopram modulates learning content-specific neuroplasticity of functional brain networks
by
Gryglewski, Gregor
,
Hahn, Andreas
,
Handschuh, Patricia
in
Adult
,
Animal models
,
Antidepressants
2022
Learning-induced neuroplastic changes, further modulated by content and setting, are mirrored in brain functional connectivity (FC). In animal models, selective serotonin reuptake inhibitors (SSRIs) have been shown to facilitate neuroplasticity. This is especially prominent during emotional relearning, such as fear extinction, which may translate to clinical improvements in patients. To investigate a comparable modulation of neuroplasticity in humans, 99 healthy subjects underwent three weeks of emotional (matching faces) or non-emotional learning (matching Chinese characters to unrelated German nouns). Shuffled pairings of the original content were subsequently relearned for the same time. During relearning, subjects received either a daily dose of the SSRI escitalopram or placebo. Resting-state functional magnetic resonance imaging was performed before and after the (re-)learning phases. FC changes in a network comprising Broca's area, the medial prefrontal cortex, the right inferior temporal and left lingual gyrus were modulated by escitalopram intake. More specifically, it increased the bidirectional connectivity between medial prefrontal cortex and lingual gyrus for non-emotional and the connectivity from medial prefrontal cortex to Broca's area for emotional relearning. The context dependence of these effects together with behavioral correlations supports the assumption that SSRIs in clinical practice improve neuroplasticity rather than psychiatric symptoms per se. Beyond expanding the complexities of learning, these findings emphasize the influence of external factors on human neuroplasticity.
Journal Article