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1.
Death Stud ; : 1-14, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38975977

RESUMO

Little is known about how telephone crisis support workers are impacted by frequent empathic engagement with callers in crisis, including those who are suicidal. This is the only known qualitative study to specifically examine the impact of their role on telephone crisis support workers' psychological wellbeing and functioning. Eighteen telephone crisis support workers participated in semi-structured interviews, providing detailed accounts of the impact of the role on their wellbeing and functioning. Interpretive Phenomenological Analysis of interview data resulted in four key themes. Results suggest that telephone crisis support workers' motivations, background, personal help-seeking and coping practices are likely to impact their experiences of psychological wellbeing and functioning in relation to empathic engagement with callers in crisis. Telephone crisis services should seek to integrate an understanding of workers' experiences into the provision of training, supervision and support strategies to optimize workers' wellbeing and functioning.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38853153

RESUMO

PURPOSE: Prostate-specific membrane antigen (PSMA) is increasingly used to image prostate cancer in clinical practice. We sought to develop and test a humanised PSMA minibody IAB2M conjugated to the fluorophore IRDye 800CW-NHS ester in men undergoing robot-assisted laparoscopic radical prostatectomy (RARP) to image prostate cancer cells during surgery. METHODS: The minibody was evaluated pre-clinically using PSMA positive/negative xenograft models, following which 23 men undergoing RARP between 2018 and 2020 received between 2.5 mg and 20 mg of IR800-IAB2M intravenously, at intervals between 24 h and 17 days prior to surgery. At every step of the procedure, the prostate, pelvic lymph node chains and extra-prostatic surrounding tissue were imaged with a dual Near-infrared (NIR) and white light optical platform for fluorescence in vivo and ex vivo. Histopathological evaluation of intraoperative and postoperative microscopic fluorescence imaging was undertaken for verification. RESULTS: Twenty-three patients were evaluated to optimise both the dose of the reagent and the interval between injection and surgery and secure the best possible specificity of fluorescence images. Six cases are presented in detail as exemplars. Overall sensitivity and specificity in detecting non-lymph-node extra-prostatic cancer tissue were 100% and 65%, and 64% and 64% respectively for lymph node positivity. There were no side-effects associated with administration of the reagent. CONCLUSION: Intraoperative imaging of prostate cancer tissue is feasible and safe using IR800-IAB2M. Further evaluation is underway to assess the benefit of using the technique in improving completion of surgical excision during RARP. REGISTRATION: ISCRCTN10046036: https://www.isrctn.com/ISRCTN10046036 .

3.
J Exp Med ; 221(8)2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38935072

RESUMO

Germinal centers (GC) are microanatomical lymphoid structures where affinity-matured memory B cells and long-lived bone marrow plasma cells are primarily generated. It is unclear how the maturation of B cells within the GC impacts the breadth and durability of B cell responses to influenza vaccination in humans. We used fine needle aspiration of draining lymph nodes to longitudinally track antigen-specific GC B cell responses to seasonal influenza vaccination. Antigen-specific GC B cells persisted for at least 13 wk after vaccination in two out of seven individuals. Monoclonal antibodies (mAbs) derived from persisting GC B cell clones exhibit enhanced binding affinity and breadth to influenza hemagglutinin (HA) antigens compared with related GC clonotypes isolated earlier in the response. Structural studies of early and late GC-derived mAbs from one clonal lineage in complex with H1 and H5 HAs revealed an altered binding footprint. Our study shows that inducing sustained GC reactions after influenza vaccination in humans supports the maturation of responding B cells.


Assuntos
Linfócitos B , Centro Germinativo , Vacinas contra Influenza , Vacinação , Centro Germinativo/imunologia , Humanos , Vacinas contra Influenza/imunologia , Linfócitos B/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Influenza Humana/imunologia , Influenza Humana/prevenção & controle , Anticorpos Antivirais/imunologia , Anticorpos Monoclonais/imunologia , Adulto , Feminino , Masculino , Pessoa de Meia-Idade
4.
Eur J Clin Invest ; : e14275, 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38943528

RESUMO

OBJECTIVES: Post-cardiac and aortic surgery stroke is often underreported. We detail our single-centre experience the following introduction of comprehensive consultant-led daily stroke service, to demonstrate the efficacy of a stroke team in recovery from stroke following cardiac and aortic surgeries. METHODS: This retrospective, single-centre observational cohort study analysed consecutive patients undergoing cardiac and aortic surgery at our institution from August 2014 to December 2020. Main outcomes included stroke rate, predictors of stroke, and neurological deficit resolution or persistence at discharge and clinic follow-up. RESULTS: A total of 12,135 procedures were carried out in the reference period. Among these, 436 (3.6%) suffered a stroke. Overall survival to discharge and follow-up were 86.0% and 84.0% respectively. Independent risk factors for post-operative stroke included advanced age (OR 1.033, 95% CI [1.023, 1.044], p < .001), female sex (OR 1.491, 95% [1.212, 1.827], p < .001), history of previous cardiac surgeries (OR 1.670, 95% CI [1.239, 2.218], p < .001), simultaneous coronary artery bypass graft + valve procedures (OR 1.825, 95% CI [1.382, 2.382], p < .001) and CPB time longer than 240 min (OR 3.384, 95% CI [2.413, 4.705], p < .001). Stroke patients managed by the multidisciplinary team demonstrated significantly higher rates of survival at discharge (87.3% vs. 61.9%, p = .001). CONCLUSIONS: Perioperative stroke can be debilitating immediately long term. The involvement of specialist stroke teams plays a key role in reducing the long-term burden and mortality of this condition.

5.
Nat Commun ; 15(1): 4056, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38744813

RESUMO

The fusion peptide of SARS-CoV-2 spike protein is functionally important for membrane fusion during virus entry and is part of a broadly neutralizing epitope. However, sequence determinants at the fusion peptide and its adjacent regions for pathogenicity and antigenicity remain elusive. In this study, we perform a series of deep mutational scanning (DMS) experiments on an S2 region spanning the fusion peptide of authentic SARS-CoV-2 in different cell lines and in the presence of broadly neutralizing antibodies. We identify mutations at residue 813 of the spike protein that reduced TMPRSS2-mediated entry with decreased virulence. In addition, we show that an F823Y mutation, present in bat betacoronavirus HKU9 spike protein, confers resistance to broadly neutralizing antibodies. Our findings provide mechanistic insights into SARS-CoV-2 pathogenicity and also highlight a potential challenge in developing broadly protective S2-based coronavirus vaccines.


Assuntos
Anticorpos Neutralizantes , COVID-19 , Mutação , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Internalização do Vírus , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismo , Humanos , SARS-CoV-2/imunologia , SARS-CoV-2/genética , Anticorpos Neutralizantes/imunologia , COVID-19/virologia , COVID-19/imunologia , Animais , Anticorpos Antivirais/imunologia , Serina Endopeptidases/genética , Serina Endopeptidases/imunologia , Serina Endopeptidases/metabolismo , Chlorocebus aethiops , Células HEK293 , Células Vero , Epitopos/imunologia , Epitopos/genética , Linhagem Celular , Camundongos
6.
Vaccines (Basel) ; 12(5)2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38793718

RESUMO

Public antibody responses have been found against many infectious agents. Structural convergence of public antibodies is usually determined by immunoglobulin V genes. Recently, a human antibody public class against SARS-CoV-2 was reported, where the D gene (IGHD3-22) encodes a common YYDxxG motif in heavy-chain complementarity-determining region 3 (CDR H3), which determines specificity for the receptor-binding domain (RBD). In this review, we discuss the isolation, structural characterization, and genetic analyses of this class of antibodies, which have been isolated from various cohorts of COVID-19 convalescents and vaccinees. All eleven YYDxxG antibodies with available structures target the SARS-CoV-2 RBD in a similar binding mode, where the CDR H3 dominates the interaction with antigen. The antibodies target a conserved site on the RBD that does not overlap with the receptor-binding site, but their particular angle of approach results in direct steric hindrance to receptor binding, which enables both neutralization potency and breadth. We also review the properties of CDR H3-dominant antibodies that target other human viruses. Overall, unlike most public antibodies, which are identified by their V gene usage, this newly discovered public class of YYDxxG antibodies is dominated by a D-gene-encoded motif and uncovers further opportunities for germline-targeting vaccine design.

7.
J Pharm Biomed Anal ; 246: 116238, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38805849

RESUMO

Drugs and drug metabolites containing a carboxylic-acid moiety can undergo in vivo conjugation to form 1-ß-O-acyl-glucuronides (1-ß-O-AGs). In addition to hydrolysis, these conjugates can undergo spontaneous acyl migration, and anomerisation reactions, resulting in a range of positional isomers. Facile transacylation has been suggested as a mechanism contributing to the toxicity of acyl glucuronides, with the kinetics of these processes thought to be a factor. Previous 1H NMR spectroscopic and HPLC-MS studies have been conducted to measure the degradation rates of the 1-ß-O-AGs of three nonsteroidal anti-inflammatory drugs (ibufenac, R-ibuprofen, S-ibuprofen) and a dimethyl-analogue (termed here as "bibuprofen"). These studies have also determined the relative contributions of hydrolysis and acyl migration in both buffered aqueous solution, and human plasma. Here, a detailed kinetic analysis is reported, providing the individual rate constants for the acyl migration and hydrolysis reactions observed in buffer for each of the 4 AGs, together with the overall degradation rate constants of the parent 1-ß-O-AGs. Computational modelling of the reactants and transition states of the transacylation reaction using density functional theory indicated differences in the activation energies that reflected the influence of both substitution and stereochemistry on the rate of transacylation/hydrolysis.


Assuntos
Desenho de Fármacos , Glucuronídeos , Ibuprofeno , Ibuprofeno/química , Hidrólise , Acilação , Glucuronídeos/química , Humanos , Anti-Inflamatórios não Esteroides/química , Cinética , Espectroscopia de Ressonância Magnética/métodos , Química Computacional/métodos , Espectroscopia de Prótons por Ressonância Magnética/métodos , Cromatografia Líquida de Alta Pressão/métodos
8.
Proc Natl Acad Sci U S A ; 121(22): e2310677121, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38753503

RESUMO

Seasonal and pandemic-associated influenza strains cause highly contagious viral respiratory infections that can lead to severe illness and excess mortality. Here, we report on the optimization of our small-molecule inhibitor F0045(S) targeting the influenza hemagglutinin (HA) stem with our Sulfur-Fluoride Exchange (SuFEx) click chemistry-based high-throughput medicinal chemistry (HTMC) strategy. A combination of SuFEx- and amide-based lead molecule diversification and structure-guided design led to identification and validation of ultrapotent influenza fusion inhibitors with subnanomolar EC50 cellular antiviral activity against several influenza A group 1 strains. X-ray structures of six of these compounds with HA indicate that the appended moieties occupy additional pockets on the HA surface and increase the binding interaction, where the accumulation of several polar interactions also contributes to the improved affinity. The compounds here represent the most potent HA small-molecule inhibitors to date. Our divergent HTMC platform is therefore a powerful, rapid, and cost-effective approach to develop bioactive chemical probes and drug-like candidates against viral targets.


Assuntos
Antivirais , Glicoproteínas de Hemaglutininação de Vírus da Influenza , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Humanos , Antivirais/farmacologia , Antivirais/química , Química Farmacêutica/métodos , Ensaios de Triagem em Larga Escala/métodos , Influenza Humana/tratamento farmacológico , Influenza Humana/virologia , Cristalografia por Raios X/métodos , Química Click/métodos , Animais , Vírus da Influenza A/efeitos dos fármacos , Células Madin Darby de Rim Canino , Inibidores de Proteínas Virais de Fusão/farmacologia , Inibidores de Proteínas Virais de Fusão/química , Cães
9.
Xenobiotica ; : 1-12, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38794972

RESUMO

In vitro studies using rat, mouse, and human microsomes and hepatocytes on the bacterial ß-glucuronidase inhibitor 1-((6,8-dimethyl-2-oxo-1,2-dihydroquinolin-3-yl)methyl)-3-(4-ethoxyphenyl)-1-(2-hydroxyethyl)thiourea) (Inh 1) revealed extensive metabolism in all species.The intrinsic clearances of Inh 1 in human, mouse, and rat hepatic microsomes were 30.9, 67.8, and 201 µL/min/mg, respectively. For intact hepatocytes intrinsic clearances of 21.6, 96.0, and 129 µL/min/106 cells were seen for human, mouse and rat, respectively.The metabolism of Inh 1 involved an uncommon desulphurisation reaction in addition to oxidation, deethylation, and conjugation reactions at multiple sites. Six metabolites were detected in microsomal incubations in human and rat, and seven for the mouse. With hepatocytes, 18 metabolites were characterised, 9 for human, and 11 for mouse and rat.Following IV administration to mice (3 mg/kg), plasma concentrations of Inh 1 exhibited a monophasic decline with a terminal elimination half-life of 0.91 h and low systemic clearance (11.8% of liver blood flow). After PO dosing to mice (3 mg/kg), peak observed Inh 1 concentrations of 495 ng/mL were measured 0.5 h post dose, declining to under 10 ng/mL at 8 h post dose. The absolute oral bioavailability of Inh 1 in the mouse was ca. 26%.

10.
Nat Immunol ; 25(6): 1083-1096, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38816616

RESUMO

Current prophylactic human immunodeficiency virus 1 (HIV-1) vaccine research aims to elicit broadly neutralizing antibodies (bnAbs). Membrane-proximal external region (MPER)-targeting bnAbs, such as 10E8, provide exceptionally broad neutralization, but some are autoreactive. Here, we generated humanized B cell antigen receptor knock-in mouse models to test whether a series of germline-targeting immunogens could drive MPER-specific precursors toward bnAbs. We found that recruitment of 10E8 precursors to germinal centers (GCs) required a minimum affinity for germline-targeting immunogens, but the GC residency of MPER precursors was brief due to displacement by higher-affinity endogenous B cell competitors. Higher-affinity germline-targeting immunogens extended the GC residency of MPER precursors, but robust long-term GC residency and maturation were only observed for MPER-HuGL18, an MPER precursor clonotype able to close the affinity gap with endogenous B cell competitors in the GC. Thus, germline-targeting immunogens could induce MPER-targeting antibodies, and B cell residency in the GC may be regulated by a precursor-competitor affinity gap.


Assuntos
Afinidade de Anticorpos , Linfócitos B , Centro Germinativo , Anticorpos Anti-HIV , HIV-1 , Centro Germinativo/imunologia , Animais , Camundongos , Humanos , Linfócitos B/imunologia , HIV-1/imunologia , Anticorpos Anti-HIV/imunologia , Afinidade de Anticorpos/imunologia , Anticorpos Neutralizantes/imunologia , Infecções por HIV/imunologia , Vacinas contra a AIDS/imunologia , Receptores de Antígenos de Linfócitos B/metabolismo , Receptores de Antígenos de Linfócitos B/imunologia , Técnicas de Introdução de Genes , Camundongos Transgênicos , Anticorpos Amplamente Neutralizantes/imunologia , Camundongos Endogâmicos C57BL
11.
NPJ Vaccines ; 9(1): 74, 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38582771

RESUMO

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.

12.
bioRxiv ; 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38585787

RESUMO

The study of immunogens capable of eliciting broadly neutralizing antibodies (bnAbs) is crucial for the development of an HIV vaccine. To date, only cows, making use of their ultralong CDRH3 loops, have reliably elicited bnAbs following immunization with HIV Envelope trimers. Antibody responses to the CD4 binding site have been readily elicited by immunization of cows with a stabilized Env trimer of the BG505 strain and, with more difficulty, to the V2-apex region of Env with a cocktail of trimers. Here, we sought to determine whether the BG505 Env trimer could be engineered to generate new bnAb specificities in cows. Since the cow CD4 binding site bnAbs bind to monomeric BG505 gp120, we also sought to determine whether gp120 immunization alone might be sufficient to induce bnAbs. We found that engineering the CD4 binding site by mutation of a key binding residue of BG505 HIV Env resulted in a reduced bnAb response that took more immunizations to develop. Monoclonal antibodies isolated from one animal were directed to the V2-apex, suggesting a re-focusing of the bnAb response. Immunization with monomeric BG505 g120 generated no serum bnAb responses, indicating that the ultralong CDRH3 bnAbs are only elicited in the context of the trimer in the absence of many other less restrictive epitopes presented on monomeric gp120. The results support the notion of a hierarchy of epitopes on HIV Env and suggest that, even with the presence in the cow repertoire of ultralong CDRH3s, bnAb epitopes are relatively disfavored.

13.
Talanta ; 274: 125970, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38621320

RESUMO

The use of collision cross section (CCS) values derived from ion mobility studies is proving to be an increasingly important tool in the characterization and identification of molecules detected in complex mixtures. Here, a novel machine learning (ML) based method for predicting CCS integrating both molecular modeling (MM) and ML methodologies has been devised and shown to be able to accurately predict CCS values for singly charged small molecular weight molecules from a broad range of chemical classes. The model performed favorably compared to existing models, improving compound identifications for isobaric analytes in terms of ranking and assigning identification probability values to the annotation. Furthermore, charge localization was seen to be correlated with CCS prediction accuracy and with gas-phase proton affinity demonstrating the potential to provide a proxy for prediction error based on chemical structural properties. The presented approach and findings represent a further step towards accurate prediction and application of computationally generated CCS values.

14.
Sci Immunol ; 9(94): eadi8039, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38579013

RESUMO

Vaccine adjuvants increase the breadth of serum antibody responses, but whether this is due to the generation of antigen-specific B cell clones with distinct specificities or the maturation of memory B cell clones that produce broadly cross-reactive antibodies is unknown. Here, we longitudinally analyzed immune responses in healthy adults after two-dose vaccination with either a virus-like particle COVID-19 vaccine (CoVLP), CoVLP adjuvanted with AS03 (CoVLP+AS03), or a messenger RNA vaccination (mRNA-1273). CoVLP+AS03 enhanced the magnitude and durability of circulating antibodies and antigen-specific CD4+ T cell and memory B cell responses. Antigen-specific CD4+ T cells in the CoVLP+AS03 group at day 42 correlated with antigen-specific memory B cells at 6 months. CoVLP+AS03 induced memory B cell responses, which accumulated somatic hypermutations over 6 months, resulting in enhanced neutralization breadth of monoclonal antibodies. Furthermore, the fraction of broadly neutralizing antibodies encoded by memory B cells increased between day 42 and 6 months. These results indicate that AS03 enhances the antigenic breadth of B cell memory at the clonal level and induces progressive maturation of the B cell response.


Assuntos
COVID-19 , Vacinas contra Influenza , Influenza Humana , Polissorbatos , Esqualeno , alfa-Tocoferol , Adulto , Humanos , Células B de Memória , Vacinas contra COVID-19 , Anticorpos Antivirais , COVID-19/prevenção & controle , Combinação de Medicamentos
15.
J Clin Med ; 13(5)2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38592237

RESUMO

Background: Mucopolysaccharidoses (MPSs) are rare congenital lysosomal storage disorders due to a deficiency of enzymes metabolising glycosaminoglycans, leading to their accumulation in tissues. This multisystem disease often requires surgical intervention, including valvular cardiac surgery. Adult MPSs have complex airways making anaesthesia risky. Methods: We report novel three-dimensional (3D) modelling airway assessments and multidisciplinary peri-operative airway management. Results: Five MPS adults underwent cardiac surgery at the national MPS cardiac centre (type I = 4, type II = 1; ages 20, 24, 33, 35, 37 years; two males, three females). All had complex airway abnormalities. Assessments involved examination, nasendoscopy, imaging, functional studies, 3D reconstruction, virtual endoscopy, virtual reality and simulation using computerised, physical modelling. Awake oral fibre-optic intubation was achieved via airway conduit. Staged extubation was performed on the first post-operative day under laryngo-tracheoscopic guidance. The post-operative period involved chest physiotherapy and occupational therapy. All patients had safe intubation, ventilation and extubation. Four had good cardiac surgical outcomes, one (MPS type I; age 35 years) was inoperable due to endocarditis. None had post-operative airway complications. Conclusions: Expertise from cardiovascular-heart team, multidisciplinary airway management, use of novel techniques is vital. Traditional airway assessments are insufficient, so ENT input, radiology and computerised methods to assess and simulate the airway in 3D by collaboration with clinical engineering is essential.

16.
PLoS One ; 19(3): e0292003, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38483984

RESUMO

BACKGROUND: This study sought to evaluate the safety, efficacy, and resource utilization of a pilot outpatient surgery program for total hip arthroplasty compared to traditional inpatient total hip arthroplasty performed via the posterolateral approach. METHODS: A cohort of 68 patients from two sites were enrolled in a regional pilot project for outpatient total hip arthroplasty (THA) and matched 1:1 against a cohort of patients undergoing routine inpatient THA. Data was extracted retrospectively from patient and hospital charts including adverse events (AE), readmission within 90 days, emergency room (ER) visits, patient calls, patient-reported outcome measures, length of stay, and multiple surgical variables. RESULTS: The outpatient group had a mean hospital stay of 13 hours, whereas the inpatient group had a mean of 58 hours (p<0.001). Three outpatients and four inpatients experienced post-op complications. Three inpatients and one outpatient visited the ER within 8 weeks of surgery. No difference in pre-operative hemoglobin (p = 0.210), or surgical blood loss (p = 0.550) was found between study groups. There was no difference found between groups regarding Oxford-12 Hip Score improvement, nor satisfaction at six months, one and two years (p>0.125). CONCLUSION: This study demonstrates that outpatient THA using the posterolateral approach is as safe and effective as inpatient THA for overall healthy and carefully screened patients, based on the low rate of AEs observed and similar patient outcomes reported. Significantly reduced time in hospital demonstrates the reduced healthcare resources associated with outpatient THA.


Assuntos
Artroplastia de Quadril , Humanos , Artroplastia de Quadril/efeitos adversos , Pacientes Ambulatoriais , Estudos Retrospectivos , Projetos Piloto , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Tempo de Internação , Readmissão do Paciente
17.
bioRxiv ; 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38496645

RESUMO

Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) cause human respiratory diseases and are major targets for vaccine development. In this study, we designed uncleaved prefusion-closed (UFC) trimers for the fusion (F) proteins of both viruses by examining mutations critical to F metastability. For RSV, we assessed four previous prefusion F designs, including the first and second generations of DS-Cav1, SC-TM, and 847A. We then identified key mutations that can maintain prefusion F in a native-like, closed trimeric form (up to 76%) without introducing any interprotomer disulfide bond. For hMPV, we developed a stable UFC trimer with a truncated F2-F1 linkage and an interprotomer disulfide bond. Tens of UFC constructs were characterized by negative-stain electron microscopy (nsEM), x-ray crystallography (11 RSV-F and one hMPV-F structures), and antigenic profiling. Using an optimized RSV-F UFC trimer as bait, we identified three potent RSV neutralizing antibodies (NAbs) from a phage-displayed human antibody library, with a public NAb lineage targeting sites Ø and V and two cross-pneumovirus NAbs recognizing site III. In mouse immunization, rationally designed RSV-F and hMPV-F UFC trimers induced robust antibody responses with high neutralizing titers. Our study provides a foundation for future prefusion F-based RSV and hMPV vaccine development.

18.
Structure ; 32(6): 766-779.e7, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38537643

RESUMO

Endolysosomal exonucleases PLD3 and PLD4 (phospholipases D3 and D4) are associated with autoinflammatory and autoimmune diseases. We report structures of these enzymes, and the molecular basis of their catalysis. The structures reveal an intra-chain dimer topology forming a basic active site at the interface. Like other PLD superfamily members, PLD3 and PLD4 carry HxKxxxxD/E motifs and participate in phosphodiester-bond cleavage. The enzymes digest ssDNA and ssRNA in a 5'-to-3' manner and are blocked by 5'-phosphorylation. We captured structures in apo, intermediate, and product states and revealed a "link-and-release" two-step catalysis. We also unexpectedly demonstrated phosphatase activity via a covalent 3-phosphohistidine intermediate. PLD4 contains an extra hydrophobic clamp that stabilizes substrate and could affect oligonucleotide substrate preference and product release. Biochemical and structural analysis of disease-associated mutants of PLD3/4 demonstrated reduced enzyme activity or thermostability and the possible basis for disease association. Furthermore, these findings provide insight into therapeutic design.


Assuntos
Domínio Catalítico , Modelos Moleculares , Fosfolipase D , Fosfolipase D/metabolismo , Fosfolipase D/química , Fosfolipase D/genética , Humanos , Especificidade por Substrato , Cristalografia por Raios X , Mutação , Lisossomos/metabolismo , Lisossomos/enzimologia , Fosforilação , DNA de Cadeia Simples/metabolismo , DNA de Cadeia Simples/química , Multimerização Proteica , Ligação Proteica , Exodesoxirribonucleases
19.
J Proteome Res ; 23(3): 956-970, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38310443

RESUMO

We present compelling evidence for the existence of an extended innate viperin-dependent pathway, which provides crucial evidence for an adaptive response to viral agents, such as SARS-CoV-2. We show the in vivo biosynthesis of a family of novel endogenous cytosine metabolites with potential antiviral activities. Two-dimensional nuclear magnetic resonance (NMR) spectroscopy revealed a characteristic spin-system motif, indicating the presence of an extended panel of urinary metabolites during the acute viral replication phase. Mass spectrometry additionally enabled the characterization and quantification of the most abundant serum metabolites, showing the potential diagnostic value of the compounds for viral infections. In total, we unveiled ten nucleoside (cytosine- and uracil-based) analogue structures, eight of which were previously unknown in humans allowing us to propose a new extended viperin pathway for the innate production of antiviral compounds. The molecular structures of the nucleoside analogues and their correlation with an array of serum cytokines, including IFN-α2, IFN-γ, and IL-10, suggest an association with the viperin enzyme contributing to an ancient endogenous innate immune defense mechanism against viral infection.


Assuntos
COVID-19 , Humanos , Estrutura Molecular , SARS-CoV-2 , Imunidade Inata , Citosina , Redes e Vias Metabólicas , Antivirais
20.
bioRxiv ; 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38405899

RESUMO

The generation of broadly neutralizing antibodies (bnAbs) to specific HIV epitopes of the HIV Envelope (Env) is one of the cornerstones of HIV vaccine research. The current animal models we use have been unable to reliable produce a broadly neutralizing antibody response, with the exception of cows. Cows have rapidly and reliably produced a CD4 binding site response by homologous prime and boosting with a native-like Env trimer. In small animal models other engineered immunogens previously have been able to focus antibody responses to the bnAb V2-apex region of Env. Here, we immunized two groups of cows (n=4) with two regiments of V2-apex focusing immunogens to investigate whether antibody responses could be directed to the V2-apex on Env. Group 1 were immunized with chimpanzee simian immunodeficiency virus (SIV)-Env trimer that shares its V2-apex with HIV, followed by immunization with C108, a V2-apex focusing immunogen, and finally boosted with a cross-clade native-like trimer cocktail. Group 2 were immunized with HIV C108 Env trimer followed by the same HIV trimer cocktail as Group 1. Longitudinal serum analysis showed that one cow in each group developed serum neutralizing antibody responses to the V2-apex. Eight and 11 bnAbs were isolated from Group 1 and Group 2 cows respectively. The best bnAbs had both medium breadth and potency. Potent and broad responses developed later than previous CD4bs cow bnAbs and required several different immunogens. All isolated bnAbs were derived from the ultralong CDRH3 repertoire. The finding that cow antibodies can target multiple broadly neutralizing epitopes on the HIV surface reveals important insight into the generation of immunogens and testing in the cow animal model. The exclusive isolation of ultralong CDRH3 bnAbs, despite only comprising a small percent of the cow repertoire, suggests these antibodies outcompete the long and short CDRH3 antibodies during the bnAb response.

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