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Influenza B viruses (IBVs) comprise a substantial portion of the circulating seasonal human influenza viruses. Here, we describe the isolation of human monoclonal antibodies (mAbs) that recognized the IBV neuraminidase (NA) glycoprotein from an individual following seasonal vaccination. Competition-binding experiments suggested the antibodies recognized two major antigenic sites. One group, which included mAb FluB-393, broadly inhibited IBV NA sialidase activity, protected prophylactically in vivo, and bound to the lateral corner of NA. The second group contained an active site mAb, FluB-400, that broadly inhibited IBV NA sialidase activity and virus replication in vitro in primary human respiratory epithelial cell cultures and protected against IBV in vivo when administered systemically or intranasally. Overall, the findings described here shape our mechanistic understanding of the human immune response to the IBV NA glycoprotein through the demonstration of two mAb delivery routes for protection against IBV and the identification of potential IBV therapeutic candidates.
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Anticorpos Monoclonais , Anticorpos Antivirais , Vírus da Influenza B , Influenza Humana , Neuraminidase , Neuraminidase/imunologia , Humanos , Vírus da Influenza B/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Influenza Humana/imunologia , Influenza Humana/prevenção & controle , Vacinas contra Influenza/imunologia , Camundongos , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Proteínas Virais/imunologia , Replicação Viral/efeitos dos fármacosRESUMO
In silico simulation of high-throughput sequencing data is a technique used widely in the genomics field. However, there is currently a lack of effective tools for creating simulated data from nanopore sequencing devices, which measure DNA or RNA molecules in the form of time-series current signal data. Here, we introduce Squigulator, a fast and simple tool for simulation of realistic nanopore signal data. Squigulator takes a reference genome, a transcriptome, or read sequences, and generates corresponding raw nanopore signal data. This is compatible with basecalling software from Oxford Nanopore Technologies (ONT) and other third-party tools, thereby providing a useful substrate for development, testing, debugging, validation, and optimization at every stage of a nanopore analysis workflow. The user may generate data with preset parameters emulating specific ONT protocols or noise-free "ideal" data, or they may deterministically modify a range of experimental variables and/or noise parameters to shape the data to their needs. We present a brief example of Squigulator's use, creating simulated data to model the degree to which different parameters impact the accuracy of ONT basecalling and downstream variant detection. This analysis reveals new insights into the nature of ONT data and basecalling algorithms. We provide Squigulator as an open-source tool for the nanopore community.
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Sequenciamento por Nanoporos , Software , Sequenciamento por Nanoporos/métodos , Simulação por Computador , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Nanoporos , Humanos , Genômica/métodos , Análise de Sequência de DNA/métodos , AlgoritmosRESUMO
MOTIVATION: Nanopore sequencing current signal data can be 'basecalled' into sequence information or analysed directly, with the capacity to identify diverse molecular features, such as DNA/RNA base modifications and secondary structures. However, raw signal data is large and complex, and there is a need for improved visualization strategies to facilitate signal analysis, exploration and tool development. RESULTS: Squigualiser (Squiggle visualiser) is a toolkit for intuitive, interactive visualization of sequence-aligned signal data, which currently supports both DNA and RNA sequencing data from Oxford Nanopore Technologies instruments. Squigualiser is compatible with a wide range of alternative signal-alignment software packages and enables visualization of both signal-to-read and signal-to-reference aligned data at single-base resolution. Squigualiser generates an interactive signal browser view (HTML file), in which the user can navigate across a genome/transcriptome region and customize the display. Multiple independent reads are integrated into a 'signal pileup' format and different datasets can be displayed as parallel tracks. Although other methods exist, Squigualiser provides the community with a software package purpose-built for raw signal data visualization, incorporating a range of new and existing features into a unified platform. AVAILABILITY AND IMPLEMENTATION: Squigualiser is an open-source package under an MIT licence: https://github.com/hiruna72/squigualiser. The software was developed using Python 3.8 and can be installed with pip or bioconda or executed directly using prebuilt binaries provided with each release.
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Sequenciamento por Nanoporos , Software , Sequenciamento por Nanoporos/métodos , Análise de Sequência de DNA/métodos , Alinhamento de Sequência/métodos , Análise de Sequência de RNA/métodosRESUMO
Aggregation of transthyretin (TTR) is associated with devastating amyloid diseases. Amyloidosis begins with the dissociation of the native homotetramer (a dimer of dimers) to form a monomeric intermediate that assembles into pathogenic aggregates. This process is accelerated in vitro at low pH, but the process by which TTR dissociates and reassembles at neutral pH remains poorly characterized due to the low population of intermediates. Here, we use 19F-nuclear magnetic resonance (NMR) and a highly sensitive trifluoromethyl probe to determine the relative populations of the species formed by the dissociation of a destabilized variant, A25T. The A25T mutation perturbs both the strong dimer and weak dimer-dimer interfaces. A tetramerâ¯ââ¯dimerâ¯ââ¯monomer (TDM) equilibrium model is proposed to account for concentration- and temperature-dependent population changes. Thermodynamic and kinetic parameters and activation energetics for dissociation of the native A25T tetramer, as well as a destabilized alternative tetramer (T*) with a mispacked F87 side chain, were extracted by van't Hoff and 19F-NMR line shape analysis, saturation transfer, and transition state theory. Chemical shifts for the dimer and T* species are degenerate for 19F and methyl probes close to the strong dimer interface, implicating interfacial perturbation as a common structural feature of these destabilized species. All-atom molecular dynamics simulations further suggest more frequent F87 ring flipping on the nanosecond time scale in the A25T dimer than in the native A25T tetramer. Our integrated approach offers quantitative insights into the energy landscape of the dissociation pathway of TTR at neutral pH.
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Pré-Albumina , Pré-Albumina/genética , Pré-Albumina/química , Pré-Albumina/metabolismo , Mutação , Espectroscopia de Ressonância MagnéticaRESUMO
In the Emergency Department, patients with suspected myocardial infarction can be risk stratified using the HEART pathway, which has recently been amended for prehospital use and modified for the incorporation of a high-sensitivity cardiac troponin test. In a prospective analysis, the performance of both HEART pathways in the prehospital setting, with a high-sensitivity cardiac troponin test using 3 different thresholds, was evaluated for major adverse cardiac events at 30 days. We found that both low-risk HEART pathways, when using the most conservative cardiac troponin thresholds, approached but did not reach accepted rule-out performance in the Emergency Department.
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Serviços Médicos de Emergência , Infarto do Miocárdio , Humanos , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/sangue , Serviços Médicos de Emergência/métodos , Estudos Prospectivos , Medição de Risco/métodos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Biomarcadores/sangue , Serviço Hospitalar de Emergência , Pessoal Técnico de Saúde , Troponina/sangue , Auxiliares de Emergência , ParamédicoRESUMO
Normothermic machine perfusion (NMP) enables pretransplant assessment of high-risk donor livers. The VITTAL trial demonstrated that 71% of the currently discarded organs could be transplanted with 100% 90-day patient and graft survivals. Here, we report secondary end points and 5-year outcomes of this prospective, open-label, phase 2 adaptive single-arm study. The patient and graft survivals at 60 months were 82% and 72%, respectively. Four patients lost their graft due to nonanastomotic biliary strictures, one caused by hepatic artery thrombosis in a liver donated following brain death, and 3 in elderly livers donated after circulatory death (DCD), which all clinically manifested within 6 months after transplantation. There were no late graft losses for other reasons. All the 4 patients who died during the study follow-up had functioning grafts. Nonanastomotic biliary strictures developed in donated after circulatory death livers that failed to produce bile with pH >7.65 and bicarbonate levels >25 mmol/L. Histological assessment in these livers revealed high bile duct injury scores characterized by arterial medial necrosis. The quality of life at 6 months significantly improved in all but 4 patients suffering from nonanastomotic biliary strictures. This first report of long-term outcomes of high-risk livers assessed by normothermic machine perfusion demonstrated excellent 5-year survival without adverse effects in all organs functioning beyond 1 year (ClinicalTrials.gov number NCT02740608).
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Transplante de Fígado , Idoso , Humanos , Constrição Patológica/etiologia , Fígado/cirurgia , Transplante de Fígado/efeitos adversos , Preservação de Órgãos , Perfusão , Estudos Prospectivos , Qualidade de VidaAssuntos
Colangite Esclerosante , Transplante de Fígado , Transtornos Linfoproliferativos , Humanos , Colangite Esclerosante/cirurgia , Colangite Esclerosante/complicações , Colangite Esclerosante/etiologia , Colangite Esclerosante/imunologia , Transplante de Fígado/efeitos adversos , Transtornos Linfoproliferativos/etiologia , Transtornos Linfoproliferativos/epidemiologia , Transtornos Linfoproliferativos/imunologia , Transtornos Linfoproliferativos/diagnóstico , Fatores de Risco , Masculino , Feminino , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/epidemiologia , Pessoa de Meia-Idade , Adulto , Imunossupressores/efeitos adversosRESUMO
Aberrant formation and deposition of human transthyretin (TTR) aggregates causes transthyretin amyloidosis. To initialize aggregation, transthyretin tetramers must first dissociate into monomers that partially unfold to promote entry into the aggregation pathway. The native TTR tetramer (T) is stabilized by docking of the F87 sidechain into an interfacial cavity enclosed by several hydrophobic residues including A120. We have previously shown that an alternative tetramer (T*) with mispacked F87 sidechains is more prone to dissociation and aggregation than the native T state. However, the molecular basis for the reduced stability in T* remains unclear. Here we report characterization of the A120L mutant, where steric hindrance is introduced into the F87 binding site. The x-ray structure of A120L shows that the F87 sidechain is displaced from its docking site across the subunit interface. In A120S, a naturally occurring pathogenic mutant that is less aggregation-prone than A120L, the F87 sidechain is correctly docked, as in the native TTR tetramer. Nevertheless, 19F-NMR aggregation assays show an elevated population of a monomeric aggregation intermediate in A120S relative to a control containing the native A120, due to accelerated tetramer dissociation and slowed monomer tetramerization. The mispacking of the F87 sidechain is associated with enhanced exchange dynamics for interfacial residues. At 298 K, the T* populations of various naturally occurring mutants fall between 4% and 7% (ΔG ~ 1.5-1.9 kcal/mol), consistent with the free energy change expected for undocking and solvent exposure of one of the four F87 sidechains in the tetramer (ΔG ~ 1.6 kcal/mol). Our data provide a molecular-level picture of the likely universal F87 sidechain mispacking in tetrameric TTR that promotes interfacial conformational dynamics and increases aggregation propensity.
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Pré-Albumina , Pré-Albumina/química , Pré-Albumina/genética , Pré-Albumina/metabolismo , Humanos , Modelos Moleculares , Cristalografia por Raios X , Conformação Proteica , Multimerização Proteica , Agregados Proteicos , Neuropatias Amiloides Familiares/genética , Neuropatias Amiloides Familiares/metabolismo , Sítios de Ligação , Substituição de AminoácidosRESUMO
BACKGROUND: As adoption of nanopore sequencing technology continues to advance, the need to maintain large volumes of raw current signal data for reanalysis with updated algorithms is a growing challenge. Here we introduce slow5curl, a software package designed to streamline nanopore data sharing, accessibility, and reanalysis. RESULTS: Slow5curl allows a user to fetch a specified read or group of reads from a raw nanopore dataset stored on a remote server, such as a public data repository, without downloading the entire file. Slow5curl uses an index to quickly fetch specific reads from a large dataset in SLOW5/BLOW5 format and highly parallelized data access requests to maximize download speeds. Using all public nanopore data from the Human Pangenome Reference Consortium (>22 TB), we demonstrate how slow5curl can be used to quickly fetch and reanalyze raw signal reads corresponding to a set of target genes from each individual in large cohort dataset (n = 91), minimizing the time, egress costs, and local storage requirements for their reanalysis. CONCLUSIONS: We provide slow5curl as a free, open-source package that will reduce frictions in data sharing for the nanopore community: https://github.com/BonsonW/slow5curl.
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Sequenciamento por Nanoporos , Nanoporos , Humanos , Algoritmos , Disseminação de Informação , RegistrosRESUMO
Aberrant formation and deposition of human transthyretin (TTR) aggregates causes transthyretin amyloidosis. To initialize aggregation, transthyretin tetramers must first dissociate into monomers that partially unfold to promote entry into the aggregation pathway. The native TTR tetramer (T) is stabilized by docking of the F87 sidechain into an interfacial cavity enclosed by several hydrophobic residues including A120. We have previously shown that an alternative tetramer (T*) with mispacked F87 sidechains is more prone to dissociation and aggregation than the native T state. However, the molecular basis for the reduced stability in T* remains unclear. Here we report characterization of the A120L mutant, where steric hindrance is introduced into the F87 binding site. The X-ray structure of A120L shows that the F87 sidechain is displaced from its docking site across the subunit interface. In A120S, a naturally occurring pathogenic mutant that is less aggregation-prone than A120L, the F87 sidechain is correctly docked, as in the native TTR tetramer. Nevertheless, 19F-NMR aggregation assays show an elevated population of a monomeric aggregation intermediate in A120S relative to a control containing the native A120, due to accelerated tetramer dissociation and slowed monomer tetramerization. The mispacking of the F87 sidechain is associated with enhanced exchange dynamics for interfacial residues. At 298 K, the T* populations of various naturally occurring mutants fall between 4-7% (ΔG ~ 1.5-1.9 kcal/mol), consistent with the free energy change expected for undocking and solvent exposure of one of the four F87 sidechains in the tetramer (ΔG ~ 1.6 kcal/mol). Our data provide a molecular-level picture of the likely universal F87 sidechain mispacking in tetrameric TTR that promotes interfacial conformational dynamics and increases aggregation propensity.
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Background & Aims: Long-term follow-up studies of paediatric onset autoimmune liver disease (AILD) are invaluable in helping better understand the clinical course of disease. In day-to-day practice clinicians struggle with disease definitions whilst patients and parents lack clear prognostic information. Methods: The clinical progression of 159 patients with childhood onset AILD between June 1990 and December 2013 was reviewed, capturing data up to adulthood (ending May 2021). Results: Presentation with autoimmune hepatitis (AIH) was dominant (n = 119); biliary presentations accounted for 25%. During follow up, biliary disease progression confirmed by cholangiography and/or liver histology was observed frequently: 19.8% (20/101) patients with childhood onset AIH type 1 (AIH-1) developed biliary features by adulthood and of these 50% phenotypically transitioned to primary sclerosing cholangitis (PSC); the remaining transitioned to an overlap disease phenotype. No patients with AIH type 2 developed biliary progression. Two-thirds of patients with overlap features (14/21) in childhood had phenotypically progressed to PSC by adulthood. Approximately 43% (6/14) of AIH-1 patients requiring a liver transplant in adulthood had explant evidence of biliary disease compared with 11% (1/9) in childhood, whereas 35.7% (5/14) of patients had histology diagnostic of PSC in their explant liver and 7.1% (1/14) had overlap features. All patients with biliary phenotypes (PSC, autoimmune sclerosing cholangitis, overlap) who required a transplant (n = 18) were found to have explant histology consistent with PSC. Twelve of 14 patients with biliary progression developed ulcerative colitis during follow-up with 92% progressing to PSC. Conclusions: Three decades of follow-up demonstrated how children presenting with AILD had a significant risk of clinical transformation to PSC. Biliary progression was significantly associated with the development of inflammatory bowel disease. Impact and implications: Childhood onset autoimmune liver disease remains very impactful for patients and families. Disease nomenclature can however be confusing. Long-term follow up studies as children become adults is important to help understand how and why disease behaves over time. Understanding more about the long-term course of childhood autoimmune liver disease will help patients, families and doctors striving to improve care and reduce poor clinical outcomes. We followed over 150 patients with childhood onset autoimmune liver diseases into adulthood. We found that amongst patients with classical autoimmune hepatitis, 1 in 5 developed biliary disease over time, mostly consisting of primary sclerosing cholangitis. This was associated with developing inflammatory bowel disease. Our study design was retrospective and has relevant limitations. Defining phenotypes of autoimmune liver diseases is difficult and there is insufficient consensus, especially between adult and childhood physicians. Our data confirms the critical importance of careful long-term follow-up of patients, including safe transition to adult care, as well as robustly demonstrates, using real-world data, how disease nature can change over time. Our study affirms the need for investment in prospective cohort studies.
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Background: Primary sclerosing cholangitis (PSC) is one of the leading indications for liver transplantation in Europe, and a major risk factor for cancer in inflammatory bowel disease (IBD). However, it is not known how the epidemiology of PSC will change as that of IBD evolves. The aim of this study is to provide nationwide statistics on the past and current prevalence of PSC and IBD across England, and forecast how this is likely to change over time. Methods: We accessed and analysed a nationwide population-based administrative healthcare registry, which houses prospectively accrued data since April 1st 2001. In so doing, the past and current prevalence of PSC-IBD and IBD alone was determined among 18-60-year-olds in England, alongside average annual percentage change rates (AAPC), between the 1st of January 2015 and 2020. Past and current prevalence data, alongside trends in incidence and event-free survival rates, were then used to forecast future prevalence between 2021 and 2027. Findings: In 2015, the prevalence of PSC with prior IBD diagnosis was 5.0 per 100,000 population, rising to 5.7 when including those with IBD diagnosed after PSC. In 2020, prevalence increased to 7.6 (8.6 accounting for IBD developing after PSC), yielding an AAPC of 8.8. In 2027, PSC-IBD prevalence is forecast to be 11.7 (95% prediction interval [PI]: 10.8-12.7), and 13.3 when accounting for IBD developing after PSC (AAPC: 6.4; 95% PI: 5.3-7.5). Comparatively, the prevalence of IBD alone rose among 18-60-year-olds from 384.3 in 2015 to 538.7 in 2020 (AAPC 7.0), and forecast to increase to 742.5 by 2027 (95% PI: 736.4-748.0; AAPC: 4.7, 95% PI: 4.6-4.8). Interpretation: The rate of growth in PSC-IBD is predicted to exceed IBD-alone. Further research is needed to understand changes in disease epidemiology, including aetiological drivers of developing (invariably progressive) liver disease in IBD, and the implications of rising case burden on health care resources. Funding: This study was supported by an unrestricted grant provided by Gilead Sciences.
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Objective: To compare outcomes in patients undergoing robotic-assisted radical cystectomy (RARC) with urinary diversion for bladder cancer with either the single-port (SP) or multiport (MP) robotic platform. Methods: All patients who underwent SP and MP RARC at our institution between January 2018 and January 2023 were retrospectively reviewed. Postoperative analgesia was administered by a departmentwide narcotic stewardship protocol, and inpatient and outpatient narcotic use was tracked. The available preoperative clinical, operative, and postoperative outcomes were analyzed using t-test, chi-square, and Fischer exact statistical measures. Kaplan-Meier analysis with log-rank testing was used to determine the freedom from high-grade (Clavien-Dindo grade ≥3) postoperative complications stratified by SP or MP robotic use. Results: Overall, 96 patients underwent RARC with urinary diversion at our institution, with 49 MP and 47 SP procedures performed. Preoperative clinical parameters including age, body mass index, prior abdominal surgery, and use of neoadjuvant chemotherapy were similar between the two groups. Patients undergoing SP RARC had a shorter operative time (386.0 ± 90.9 minutes vs 453.6 ± 94.8 minutes, p < 0.01) and faster return of bowel function (3.4 ± 1.4 days vs 4.5 ± 2.2 days, p < 0.01). However, both cohorts had similar length of hospitalization, postoperative narcotic use, pathologic staging, and rate of positive surgical margin. Within 3 months postoperatively, both cohorts had a similar high-grade complication, hospital readmission, and cancer recurrence rate. Conclusions: The SP robot allows a safe alternative surgical approach for RARC and offers similar postoperative outcomes compared to the MP robot.
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Cistectomia , Procedimentos Cirúrgicos Robóticos , Neoplasias da Bexiga Urinária , Humanos , Cistectomia/métodos , Procedimentos Cirúrgicos Robóticos/métodos , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Neoplasias da Bexiga Urinária/cirurgia , Dor Pós-Operatória/etiologia , Dor Pós-Operatória/tratamento farmacológico , Analgésicos/uso terapêutico , Derivação Urinária/métodos , Complicações Pós-Operatórias/etiologia , Analgesia/métodos , Duração da CirurgiaRESUMO
The aggregation pathway of transthyretin (TTR) proceeds through rate-limiting dissociation of the tetramer (a dimer of dimers) and partial misfolding of the resulting monomer, which assembles into amyloid structures through a downhill polymerization mechanism. The structural features of the aggregation-prone monomeric intermediate are poorly understood. NMR relaxation dispersion offers a unique opportunity to characterize amyloidogenic intermediates when they exchange on favorable timescales with NMR-visible ground states. Here we use NMR to characterize the structure and conformational dynamics of the monomeric F87E mutant of human TTR. Chemical shifts derived from analysis of multinuclear relaxation dispersion data provide insights into the structure of a low-lying excited state that exchanges with the ground state of the F87E monomer at a rate of 3800 s-1. Disruption of the subunit interfaces of the TTR tetramer leads to destabilization of edge strands in both ß-sheets of the F87E monomer. Conformational fluctuations are propagated through the entire hydrogen bonding network of the DAGH ß-sheet, from the inner ß-strand H, which forms the strong dimer-dimer interface in the TTR tetramer, to outer strand D which is unfolded in TTR fibrils. Fluctuations are also propagated from the AB loop in the weak dimer-dimer interface to the EF helix, which undergoes structural remodeling in fibrils. The conformational fluctuations in both regions are enhanced at acidic pH where amyloid formation is most favorable. The relaxation dispersion data provide insights into the conformational dynamics of the amyloidogenic state of monomeric TTR that predispose it for structural remodeling and progression to amyloid fibrils.
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Amiloide , Pré-Albumina , Conformação Proteica , Pré-Albumina/química , Pré-Albumina/metabolismo , Pré-Albumina/genética , Humanos , Amiloide/química , Amiloide/metabolismo , Multimerização Proteica , Modelos Moleculares , Ligação de Hidrogênio , Mutação , Ressonância Magnética Nuclear BiomolecularRESUMO
Goal: We present a new framework for in vivo image guidance evaluation and provide a case study on robotic partial nephrectomy. Methods: This framework (called the "bystander protocol") involves two surgeons, one who solely performs the therapeutic process without image guidance, and another who solely periodically collects data to evaluate image guidance. This isolates the evaluation from the therapy, so that in-development image guidance systems can be tested without risk of negatively impacting the standard of care. We provide a case study applying this protocol in clinical cases during robotic partial nephrectomy surgery. Results: The bystander protocol was performed successfully in 6 patient cases. We find average lesion centroid localization error with our IGS system to be 6.5 mm in vivo compared to our prior result of 3.0 mm in phantoms. Conclusions: The bystander protocol is a safe, effective method for testing in-development image guidance systems in human subjects.
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INTRODUCTION: Improved outcomes of liver disease in childhood and young adulthood have resulted in an increasing number of young adults (YA) entering adult liver services. The adult hepatologist therefore requires a working knowledge in diseases that arise almost exclusively in children and their complications in adulthood. AIMS: To provide adult hepatologists with succinct guidelines on aspects of transitional care in YA relevant to key disease aetiologies encountered in clinical practice. METHODS: A systematic literature search was undertaken using the Pubmed, Medline, Web of Knowledge and Cochrane database from 1980 to 2023. MeSH search terms relating to liver diseases ('cholestatic liver diseases', 'biliary atresia', 'metabolic', 'paediatric liver diseases', 'autoimmune liver diseases'), transition to adult care ('transition services', 'young adult services') and adolescent care were used. The quality of evidence and the grading of recommendations were appraised using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. RESULTS: These guidelines deal with the transition of YA and address key aetiologies for the adult hepatologist under the following headings: (1) Models and provision of care; (2) screening and management of mental health disorders; (3) aetiologies; (4) timing and role of liver transplantation; and (5) sexual health and fertility. CONCLUSIONS: These are the first nationally developed guidelines on the transition and management of childhood liver diseases in adulthood. They provide a framework upon which to base clinical care, which we envisage will lead to improved outcomes for YA with chronic liver disease.
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Colestase , Hepatopatias , Transplante de Fígado , Adolescente , Criança , Humanos , Adulto Jovem , Hepatopatias/diagnóstico , Hepatopatias/terapia , Reino UnidoRESUMO
Plasmodium falciparum pathology is driven by the accumulation of parasite-infected erythrocytes in microvessels. This process is mediated by the parasite's polymorphic erythrocyte membrane protein 1 (PfEMP1) adhesion proteins. A subset of PfEMP1 variants that bind human endothelial protein C receptor (EPCR) through their CIDRα1 domains is responsible for severe malaria pathogenesis. A longstanding question is whether individual antibodies can recognize the large repertoire of circulating PfEMP1 variants. Here, we describe two broadly reactive and binding-inhibitory human monoclonal antibodies against CIDRα1. The antibodies isolated from two different individuals exhibited a similar and consistent EPCR-binding inhibition of 34 CIDRα1 domains, representing five of the six subclasses of CIDRα1. Both antibodies inhibited EPCR binding of both recombinant full-length and native PfEMP1 proteins as well as parasite sequestration in bioengineered 3D brain microvessels under physiologically relevant flow conditions. Structural analyses of the two antibodies in complex with two different CIDRα1 antigen variants reveal similar binding mechanisms that depend on interactions with three highly conserved amino acid residues of the EPCR-binding site in CIDRα1. These broadly reactive antibodies likely represent a common mechanism of acquired immunity to severe malaria and offer novel insights for the design of a vaccine or treatment targeting severe malaria.
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BACKGROUND AND OBJECTIVE: Despite curative-intent radical cystectomy (RC), patients with muscle-invasive bladder cancer (MIBC) are at high risk of recurrence. Biomarkers are urgently needed to refine prognostication and selection of appropriate perioperative systemic therapies. Our aim was to evaluate the prognostic and predictive value of tumor-informed circulating tumor DNA (ctDNA) results in a multicenter cohort of patients with bladder cancer who underwent RC. METHODS: We performed a retrospective analysis of real-world data for a commercial ctDNA test (Signatera; Natera, Austin, TX, USA) performed in 167 patients (852 plasma samples) before RC and during molecular residual disease (MRD; adjuvant decision) and surveillance windows. We assessed the correlation between recurrence and ctDNA status before and after RC using Cox regression analysis. RESULTS AND LIMITATIONS: During study-defined postoperative MRD and surveillance windows, detectable ctDNA was associated with shorter disease-free survival (DFS) when compared to undetectable ctDNA (MRD: hazard ratio 6.93; p < 0.001; surveillance: hazard ratio 23.02; p < 0.001). Of note, patients with undetectable ctDNA did not appear to benefit from adjuvant therapy (p = 0.34). Detectable ctDNA in the pre-RC (p = 0.045), MRD (p = 0.002), and surveillance (p < 0.001) windows was the only risk factor independently associated with shorter DFS. Limitations include the retrospective and nonrandomized nature of the study. CONCLUSIONS: ctDNA testing in patients with bladder cancer undergoing RC was prognostic and potentially predictive. Identification of patients at high risk of recurrence may aid in patient counseling and decision-making. PATIENT SUMMARY: We found that outcomes for patients with muscle-invasive bladder cancer are strongly linked to detection of tumor DNA in blood samples. The results show the value of tumor-informed testing for tumor DNA in blood for decisions on the best treatment for each individual patient.
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Recombinant native-like HIV-1 envelope glycoprotein (Env) trimers are used in candidate vaccines aimed at inducing broadly neutralizing antibodies. While state-of-the-art SOSIP or single-chain Env designs can be expressed as native-like trimers, undesired monomers, dimers and malformed trimers that elicit non-neutralizing antibodies are also formed, implying that these designs could benefit from further modifications for gene-based vaccination approaches. Here, we describe the triple tandem trimer (TTT) design, in which three Env protomers are genetically linked in a single open reading frame and express as native-like trimers. Viral vectored Env TTT induced similar neutralization titers but with a higher proportion of trimer-specific responses. The TTT design was also applied to generate influenza hemagglutinin (HA) trimers without the need for trimerization domains. Additionally, we used TTT to generate well-folded chimeric Env and HA trimers that harbor protomers from three different strains. In summary, the TTT design is a useful platform for the design of HIV-1 Env and influenza HA immunogens for a multitude of vaccination strategies.