Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Toxins (Basel) ; 16(8)2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39195746

RESUMEN

Spinal cord injury (SCI) often leads to neurogenic lower urinary tract dysfunction, causing dysuria and affecting patients' well-being. This study aimed to evaluate the efficacy of a urethral sphincter botulinum toxin A (BoNT-A) injection in patients with SCI and dysuria. This was a retrospective study including 118 patients with SCI who underwent a urethral BoNT-A injection following a standardized protocol for refractory voiding dysfunction. The protocol involved injecting BoNT-A into the urethral sphincter under cystoscopic guidance. Patient demographics, bladder condition parameters, and treatment outcomes were analyzed. Logistic regression and receiver operating characteristic curve analyses were performed to identify predictors of treatment success. Of the 118 patients, 71 (60.1%) showed satisfactory treatment outcomes after the injection. Post-injection status, bladder management, and injection frequency varied significantly among patients with satisfactory and unsatisfactory treatment outcomes. Age, bladder compliance, intravesical pressure, and bladder contractility were indicators of satisfactory outcomes. The first sensation of bladder filling of ≤263 mL, intravesical pressure of ≤28, and bladder contractility index of ≥14 were highly correlated with satisfactory outcomes. A urethral sphincter BoNT-A injection shows promise in managing dysuria in patients with SCI. Understanding bladder condition parameters and patient demographics helps optimize patient selection for this intervention. Further studies are needed to validate these findings and refine treatment protocols.


Asunto(s)
Toxinas Botulínicas Tipo A , Disuria , Traumatismos de la Médula Espinal , Uretra , Humanos , Toxinas Botulínicas Tipo A/administración & dosificación , Toxinas Botulínicas Tipo A/uso terapéutico , Traumatismos de la Médula Espinal/tratamiento farmacológico , Traumatismos de la Médula Espinal/complicaciones , Estudios Retrospectivos , Disuria/tratamiento farmacológico , Disuria/etiología , Masculino , Persona de Mediana Edad , Adulto , Uretra/efectos de los fármacos , Femenino , Resultado del Tratamiento , Anciano , Fármacos Neuromusculares/administración & dosificación , Fármacos Neuromusculares/uso terapéutico , Adulto Joven , Inyecciones , Vejiga Urinaria Neurogénica/tratamiento farmacológico , Vejiga Urinaria/efectos de los fármacos
2.
J Med Internet Res ; 26: e58599, 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39042442

RESUMEN

BACKGROUND: Diagnosing underlying causes of nonneurogenic male lower urinary tract symptoms associated with bladder outlet obstruction (BOO) is challenging. Video-urodynamic studies (VUDS) and pressure-flow studies (PFS) are both invasive diagnostic methods for BOO. VUDS can more precisely differentiate etiologies of male BOO, such as benign prostatic obstruction, primary bladder neck obstruction, and dysfunctional voiding, potentially outperforming PFS. OBJECTIVE: These examinations' invasive nature highlights the need for developing noninvasive predictive models to facilitate BOO diagnosis and reduce the necessity for invasive procedures. METHODS: We conducted a retrospective study with a cohort of men with medication-refractory, nonneurogenic lower urinary tract symptoms suspected of BOO who underwent VUDS from 2001 to 2022. In total, 2 BOO predictive models were developed-1 based on the International Continence Society's definition (International Continence Society-defined bladder outlet obstruction; ICS-BOO) and the other on video-urodynamic studies-diagnosed bladder outlet obstruction (VBOO). The patient cohort was randomly split into training and test sets for analysis. A total of 6 machine learning algorithms, including logistic regression, were used for model development. During model development, we first performed development validation using repeated 5-fold cross-validation on the training set and then test validation to assess the model's performance on an independent test set. Both models were implemented as paper-based nomograms and integrated into a web-based artificial intelligence prediction tool to aid clinical decision-making. RESULTS: Among 307 patients, 26.7% (n=82) met the ICS-BOO criteria, while 82.1% (n=252) were diagnosed with VBOO. The ICS-BOO prediction model had a mean area under the receiver operating characteristic curve (AUC) of 0.74 (SD 0.09) and mean accuracy of 0.76 (SD 0.04) in development validation and AUC and accuracy of 0.86 and 0.77, respectively, in test validation. The VBOO prediction model yielded a mean AUC of 0.71 (SD 0.06) and mean accuracy of 0.77 (SD 0.06) internally, with AUC and accuracy of 0.72 and 0.76, respectively, externally. When both models' predictions are applied to the same patient, their combined insights can significantly enhance clinical decision-making and simplify the diagnostic pathway. By the dual-model prediction approach, if both models positively predict BOO, suggesting all cases actually resulted from medication-refractory primary bladder neck obstruction or benign prostatic obstruction, surgical intervention may be considered. Thus, VUDS might be unnecessary for 100 (32.6%) patients. Conversely, when ICS-BOO predictions are negative but VBOO predictions are positive, indicating varied etiology, VUDS rather than PFS is advised for precise diagnosis and guiding subsequent therapy, accurately identifying 51.1% (47/92) of patients for VUDS. CONCLUSIONS: The 2 machine learning models predicting ICS-BOO and VBOO, based on 6 noninvasive clinical parameters, demonstrate commendable discrimination performance. Using the dual-model prediction approach, when both models predict positively, VUDS may be avoided, assisting in male BOO diagnosis and reducing the need for such invasive procedures.


Asunto(s)
Nomogramas , Obstrucción del Cuello de la Vejiga Urinaria , Urodinámica , Humanos , Obstrucción del Cuello de la Vejiga Urinaria/diagnóstico , Obstrucción del Cuello de la Vejiga Urinaria/fisiopatología , Masculino , Estudios Retrospectivos , Persona de Mediana Edad , Anciano , Inteligencia Artificial
3.
Biomed Pharmacother ; 175: 116741, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38744218

RESUMEN

Cadmium (Cd) is a widespread environmental toxicant that poses significant threat to public health. After intake, Cd is distributed throughout the body via blood and lymphatic circulation. However, the effect of Cd on lymphatic vessels has not been revealed. In this study, mice were exposed to 10 µM cadmium chloride through drinking water immediately after corneal alkali burn. In vivo analyses showed that Cd treatment enhances the alkali burn-induced corneal lymphangiogenesis, which is characterized by increased expression of lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1), prospero-related homeobox 1 (PROX-1) and vascular endothelial growth factor receptor 3 (VEGFR3). In vitro, the proliferation and migration of human dermal lymphatic endothelial cells (HDLECs) are increased by 1 µM Cd treatment, while inhibited by 10 µM Cd treatment. At a concentration of 1 µM, Cd specifically induces phosphorylation of signal transducer and activator of transcription 3 (STAT3), but has no effect on the MAPK, AKT, or NF-κB signaling pathway. In the presence of the STAT3 inhibitor STATTIC, Cd fails to induce HDLECs proliferation and migration. In addition, Cd upregulates VEGFR3 expression and its gene promoter activity in a STAT3-dependent manner. Our study suggests that low-dose Cd promotes lymphangiogenesis through activation of the STAT3 signaling pathway.


Asunto(s)
Movimiento Celular , Proliferación Celular , Linfangiogénesis , Factor de Transcripción STAT3 , Transducción de Señal , Linfangiogénesis/efectos de los fármacos , Animales , Factor de Transcripción STAT3/metabolismo , Transducción de Señal/efectos de los fármacos , Humanos , Ratones , Proliferación Celular/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Cadmio/toxicidad , Masculino , Receptor 3 de Factores de Crecimiento Endotelial Vascular/metabolismo , Relación Dosis-Respuesta a Droga , Ratones Endogámicos C57BL , Córnea/efectos de los fármacos , Córnea/metabolismo , Córnea/patología
4.
Neural Netw ; 173: 106167, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38359643

RESUMEN

Recently, due to the difficulty of collecting condition data covering all mechanical fault types in industrial scenarios, the fault diagnosis problem under incomplete data is receiving increasing attention where no target prior information can be available. The existing open-set or universal domain adaptation (DA) diagnosis methods typically treat private fault samples in the target as a generalized "unknown" fault class, neglecting their inherent structure. This oversight can lead to confusion in latent feature space representations and difficulties in separating unknown samples. Therefore, a universal DA method with unsupervised clustering is developed to explore the intrinsic structure of the target samples for mechanical fault diagnosis, where multi-source information on different working conditions is considered to transfer complementary knowledge. First, a composite clustering metric combining single-domain and cross-domain evaluation is constructed to recognize shared and unknown health classes on source-target domains. Second, to alleviate the intra-class shift while enlarging the inter-class gap, a class-wise DA algorithm is suggested which operates on the basis of maximum mean discrepancy. Finally, an entropy regularization criterion is utilized to facilitate clustering of different health classes. The efficacy of the presented approach in the fault diagnosis issues when monitoring data is inadequate has been verified through extensive experiments on three rotating machinery datasets.


Asunto(s)
Algoritmos , Conocimiento , Análisis por Conglomerados , Entropía
5.
Neural Netw ; 162: 69-82, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36889058

RESUMEN

Intelligent fault diagnosis aims to build robust mechanical condition recognition models with limited dataset. At this stage, fault diagnosis faces two practical challenges: (1) the variability of mechanical working conditions makes the collected data distribution inconsistent, which brings about the domain shift; (2) some unpredictable unknown fault modes that do not observe in the training dataset may occur in the testing scenario, leading to a category gap. In order to cope with these two entangled challenges, an open set multi-source domain adaptation approach is developed in this study. Specifically, a complementary transferability metric defined on multiple classifiers is introduced to quantify the similarity of each target sample to known classes to weight the adversarial mechanism. By applying an unknown mode detector, unknown faults can be automatically identified. Moreover, a multi-source mutual-supervised strategy is further adopted to mine relevant information between different sources to enhance the model performance. Extensive experiments are conducted on three rotating machinery datasets, and the results show that the proposed method is superior to traditional domain adaptation approaches in the mechanical diagnosis issues that new fault modes occur.


Asunto(s)
Aprendizaje Profundo , Recolección de Datos , Inteligencia , Reconocimiento en Psicología , Condiciones de Trabajo
6.
Nat Commun ; 14(1): 1130, 2023 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-36854666

RESUMEN

SARS-CoV-2 variants have emerged with elevated transmission and a higher risk of infection for vaccinated individuals. We demonstrate that a recombinant prefusion-stabilized spike (rS) protein vaccine based on Beta/B.1.351 (rS-Beta) produces a robust anamnestic response in baboons against SARS-CoV-2 variants when given as a booster one year after immunization with NVX-CoV2373. Additionally, rS-Beta is highly immunogenic in mice and produces neutralizing antibodies against WA1/2020, Beta/B.1.351, and Omicron/BA.1. Mice vaccinated with two doses of Novavax prototype NVX-CoV2373 (rS-WU1) or rS-Beta alone, in combination, or heterologous prime-boost, are protected from challenge. Virus titer is undetectable in lungs in all vaccinated mice, and Th1-skewed cellular responses are observed. We tested sera from a panel of variant spike protein vaccines and find broad neutralization and inhibition of spike:ACE2 binding from the rS-Beta and rS-Delta vaccines against a variety of variants including Omicron. This study demonstrates that rS-Beta vaccine alone or in combination with rS-WU1 induces antibody-and cell-mediated responses that are protective against challenge with SARS-CoV-2 variants and offers broader neutralizing capacity than a rS-WU1 prime/boost regimen alone. Together, these nonhuman primate and murine data suggest a Beta variant booster dose could elicit a broad immune response to fight new and future SARS-CoV-2 variants.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Nanopartículas , Animales , Humanos , Ratones , Anticuerpos Neutralizantes , COVID-19/prevención & control , Papio , SARS-CoV-2/genética , Vacunas/química , Vacunas/inmunología , Vacunas contra la COVID-19/química , Vacunas contra la COVID-19/inmunología
7.
ISA Trans ; 134: 529-547, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36068088

RESUMEN

Due to the harsh working conditions and high cost of data acquisition in the actual environment of modern rolling mills, the resulting limited datasets issue leading in performance collapse of traditional deep learning (DL) methods has been plaguing researchers and needs to be urgently addressed. Hence, an improved single-sensor Deep Belief Network (IDBN) is first proposed to repetitively extract valuable information from hidden features and visible features of the previous improved Restricted Boltzmann Machine (IRBM) to alleviate this issue. Next, the multi-sensor IDBNs (MSIDBNs) are applied to obtain complementary and enriched health state features from different multi-sensor data to cope with limited datasets more effectively. Then, the Fast Fourier Transform (FFT) technique is adopted for the multi-sensor information to further enhance the effectiveness of feature extraction. Most importantly, the redefined pretraining and finetuning stages are designed for the MSIDBNs. Meanwhile, the optimal placement of multiple sensors is fully discussed to obtain the most efficient information about health content. Finally, two limited datasets are conducted to validate the superiority of the proposed MSIDBNs. Results show that the proposed MSIDBNs are capable of extracting valuable features from multi-sensor information and achieving more remarkable performance compared with the state-of-the-art (SOTA) methods under limited datasets.

8.
Cardiovasc Ther ; 2022: 9615674, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35692375

RESUMEN

Purpose: L-carnitine (LC) is considered to have good therapeutic potential for myocardial infarction (MI), but its mechanism has not been clarified. The aim of the study is to elucidate the cardioprotective effects of LC in mice following MI and related mechanisms. Methods: ICR mice were treated with LC for 2 weeks after induction of MI with ligation of left anterior descending artery. Electrocardiographic (ECG) recording and echocardiography were used to evaluate cardiac function. H&E staining, TTC staining, and Masson staining were performed for morphological analysis and cardiac fibrosis. ELISA and immunofluorescence were utilized to detect biomarkers and inflammatory mediators. The key proteins in the Bax/Bcl-2 signaling pathway were also examined by Western blot. Results: Both echocardiography and histological measurement showed an improvement in cardiac function and morphology. Biomarkers such as LDH, NT-proBNP, cTnT, and AST, as well as the inflammatory cytokines IL-1ß, IL-6, and TNF-α, were decreased in plasma of mice receiving LC treatment after myocardial injury. In addition, the expression of α-SMA as well as the key proteins in the Bax/Bcl-2 signaling pathway in cardiac myocardium were much lower in mice with LC treatment compared to those without after MI. Conclusions: Our data suggest that LC can effectively ameliorate left ventricular (LV) remodeling after MI, and its beneficial effects on myocardial function and remodeling may be attributable at least in part to anti-inflammatory and inhibition of the Bax/Bcl-2 apoptotic signaling pathway.


Asunto(s)
Infarto del Miocardio , Remodelación Ventricular , Animales , Apoptosis , Carnitina/metabolismo , Carnitina/farmacología , Carnitina/uso terapéutico , Modelos Animales de Enfermedad , Ratones , Ratones Endogámicos ICR , Miocardio/patología , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Transducción de Señal , Proteína X Asociada a bcl-2/metabolismo
9.
Front Cardiovasc Med ; 8: 762648, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34901222

RESUMEN

The lymphatic system maintains homeostasis of the internal environment between the cells in tissues and the blood circulation. The coagulation state of lymph is determined by conditions of coagulation factors and lymphatic vessels. Internal obliteration, external compression or abnormally increased lymphatic pressure may predispose to localized lymphatic coagulation. In physiological conditions, an imbalance of antithrombin and thrombokinase reduces lymphatic thrombosis. However, the release of factor X by lymphatic endothelium injury may trigger coagulation casacade, causing blockage of lymphatic vessels and lymphedema. Heterogeneity of lymphatic vessels in various tissues may lead to distinct levels and patterns of coagulation in specific lymphatic vessels. The quantitative and qualitative measurement of clotting characteristic reveals longer time for clotting to occur in the lymph than in the blood. Cancer, infections, amyloidosis and lymph node dissection may trigger thrombosis in the lymphatic vessels. In contrast to venous or arterial thrombosis, lymphatic thrombosis has rarely been reported, and its actual prevalence is likely underestimated. In this review, we summarize the mechanisms of coagulation in lymphatic system, and discuss the lymphatic thrombosis-related diseases.

10.
Cell Rep Med ; 2(9): 100405, 2021 09 21.
Artículo en Inglés | MEDLINE | ID: mdl-34485950

RESUMEN

Recently approved vaccines have shown remarkable efficacy in limiting SARS-CoV-2-associated disease. However, with the variety of vaccines, immunization strategies, and waning antibody titers, defining the correlates of immunity across a spectrum of antibody titers is urgently required. Thus, we profiled the humoral immune response in a cohort of non-human primates immunized with a recombinant SARS-CoV-2 spike glycoprotein (NVX-CoV2373) at two doses, administered as a single- or two-dose regimen. Both antigen dose and boosting significantly altered neutralization titers and Fc-effector profiles, driving unique vaccine-induced antibody fingerprints. Combined differences in antibody effector functions and neutralization were associated with distinct levels of protection in the upper and lower respiratory tract. Moreover, NVX-CoV2373 elicited antibodies that functionally targeted emerging SARS-CoV-2 variants. Collectively, the data presented here suggest that a single dose may prevent disease via combined Fc/Fab functions but that two doses may be essential to block further transmission of SARS-CoV-2 and emerging variants.


Asunto(s)
Vacunas contra la COVID-19/inmunología , SARS-CoV-2/inmunología , Saponinas/inmunología , Animales , Anticuerpos Neutralizantes/efectos de los fármacos , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , COVID-19/inmunología , COVID-19/virología , Relación Dosis-Respuesta Inmunológica , Femenino , Inmunidad Humoral/inmunología , Inmunogenicidad Vacunal , Fragmentos Fab de Inmunoglobulinas/inmunología , Fragmentos Fc de Inmunoglobulinas/inmunología , Macaca mulatta , Masculino , Nanopartículas , Primates/inmunología , SARS-CoV-2/patogenicidad , Glicoproteína de la Espiga del Coronavirus , Vacunación
11.
bioRxiv ; 2021 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-33564763

RESUMEN

Recently approved vaccines have already shown remarkable protection in limiting SARS-CoV-2 associated disease. However, immunologic mechanism(s) of protection, as well as how boosting alters immunity to wildtype and newly emerging strains, remain incompletely understood. Here we deeply profiled the humoral immune response in a cohort of non-human primates immunized with a stable recombinant full-length SARS-CoV-2 spike (S) glycoprotein (NVX-CoV2373) at two dose levels, administered as a single or two-dose regimen with a saponin-based adjuvant Matrix-M™. While antigen dose had some effect on Fc-effector profiles, both antigen dose and boosting significantly altered overall titers, neutralization and Fc-effector profiles, driving unique vaccine-induced antibody fingerprints. Combined differences in antibody effector functions and neutralization were strongly associated with distinct levels of protection in the upper and lower respiratory tract, pointing to the presence of combined, but distinct, compartment-specific neutralization and Fc-mechanisms as key determinants of protective immunity against infection. Moreover, NVX-CoV2373 elicited antibodies functionally target emerging SARS-CoV-2 variants, collectively pointing to the critical collaborative role for Fab and Fc in driving maximal protection against SARS-CoV-2. Collectively, the data presented here suggest that a single dose may prevent disease, but that two doses may be essential to block further transmission of SARS-CoV-2 and emerging variants. HIGHLIGHTS: NVX-CoV2373 subunit vaccine elicits receptor blocking, virus neutralizing antibodies, and Fc-effector functional antibodies.The vaccine protects against respiratory tract infection and virus shedding in non-human primates (NHPs).Both neutralizing and Fc-effector functions contribute to protection, potentially through different mechanisms in the upper and lower respiratory tract.Both macaque and human vaccine-induced antibodies exhibit altered Fc-receptor binding to emerging mutants.

12.
Res Sq ; 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33619473

RESUMEN

Recently approved vaccines have already shown remarkable protection in limiting SARS-CoV-2 associated disease. However, immunologic mechanism(s) of protection, as well as how boosting alters immunity to wildtype and newly emerging strains, remain incompletely understood. Here we deeply profiled the humoral immune response in a cohort of non-human primates immunized with a stable recombinant full-length SARS-CoV-2 spike (S) glycoprotein (NVX-CoV2373) at two dose levels, administered as a single or two-dose regimen with a saponin-based adjuvant Matrix-M™. While antigen dose had some effect on Fc-effector profiles, both antigen dose and boosting significantly altered overall titers, neutralization and Fc-effector profiles, driving unique vaccine-induced antibody fingerprints. Combined differences in antibody effector functions and neutralization were strongly associated with distinct levels of protection in the upper and lower respiratory tract, pointing to the presence of combined, but distinct, compartment-specific neutralization and Fc-mechanisms as key determinants of protective immunity against infection. Moreover, NVX-CoV2373 elicited antibodies functionally target emerging SARS-CoV-2 variants, collectively pointing to the critical collaborative role for Fab and Fc in driving maximal protection against SARS-CoV-2. Collectively, the data presented here suggest that a single dose may prevent disease, but that two doses may be essential to block further transmission of SARS-CoV-2 and emerging variants.

13.
Nat Commun ; 12(1): 372, 2021 01 14.
Artículo en Inglés | MEDLINE | ID: mdl-33446655

RESUMEN

The COVID-19 pandemic continues to spread throughout the world with an urgent need for a safe and protective vaccine to effectuate herd protection and control the spread of SARS-CoV-2. Here, we report the development of a SARS-CoV-2 subunit vaccine (NVX-CoV2373) from the full-length spike (S) protein that is stable in the prefusion conformation. NVX-CoV2373 S form 27.2-nm nanoparticles that are thermostable and bind with high affinity to the human angiotensin-converting enzyme 2 (hACE2) receptor. In mice, low-dose NVX-CoV2373 with saponin-based Matrix-M adjuvant elicit high titer anti-S IgG that blocks hACE2 receptor binding, neutralize virus, and protects against SARS-CoV-2 challenge with no evidence of vaccine-associated enhanced respiratory disease. NVX-CoV2373 also elicits multifunctional CD4+ and CD8+ T cells, CD4+ follicular helper T cells (Tfh), and antigen-specific germinal center (GC) B cells in the spleen. In baboons, low-dose levels of NVX-CoV2373 with Matrix-M was also highly immunogenic and elicited high titer anti-S antibodies and functional antibodies that block S-protein binding to hACE2 and neutralize virus infection and antigen-specific T cells. These results support the ongoing phase 1/2 clinical evaluation of the safety and immunogenicity of NVX-CoV2373 with Matrix-M (NCT04368988).


Asunto(s)
Vacunas contra la COVID-19/inmunología , COVID-19/prevención & control , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Enzima Convertidora de Angiotensina 2/genética , Enzima Convertidora de Angiotensina 2/inmunología , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , COVID-19/genética , COVID-19/inmunología , COVID-19/virología , Vacunas contra la COVID-19/administración & dosificación , Vacunas contra la COVID-19/genética , Modelos Animales de Enfermedad , Femenino , Masculino , Ratones , Ratones Endogámicos BALB C , Papio , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/administración & dosificación , Glicoproteína de la Espiga del Coronavirus/genética , Linfocitos T/inmunología , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología
14.
Vaccine ; 38(50): 7892-7896, 2020 11 25.
Artículo en Inglés | MEDLINE | ID: mdl-33139139

RESUMEN

There is an urgent need for a safe and protective vaccine to control the global spread of SARS-CoV-2 and prevent COVID-19. Here, we report the immunogenicity and protective efficacy of a SARS-CoV-2 subunit vaccine (NVX-CoV2373) produced from the full-length SARS-CoV-2 spike (S) glycoprotein stabilized in the prefusion conformation. Cynomolgus macaques (Macaca fascicularis) immunized with NVX-CoV2373 and the saponin-based Matrix-M™ adjuvant induced anti-S antibody that was neutralizing and blocked binding to the human angiotensin-converting enzyme 2 (hACE2) receptor. Following intranasal and intratracheal challenge with SARS-CoV-2, immunized macaques were protected against upper and lower infection and pulmonary disease. These results support ongoing phase 1/2 clinical studies of the safety and immunogenicity of NVX-CoV2327 vaccine (NCT04368988).


Asunto(s)
Vacunas contra la COVID-19/farmacología , COVID-19/prevención & control , SARS-CoV-2/inmunología , Adyuvantes Inmunológicos/farmacología , Adolescente , Adulto , Anciano , Enzima Convertidora de Angiotensina 2/inmunología , Enzima Convertidora de Angiotensina 2/metabolismo , Animales , Anticuerpos Neutralizantes , COVID-19/inmunología , Vacunas contra la COVID-19/genética , Vacunas contra la COVID-19/inmunología , Chlorocebus aethiops , Femenino , Humanos , Sueros Inmunes/efectos de los fármacos , Sueros Inmunes/inmunología , Macaca fascicularis , Masculino , Persona de Mediana Edad , Glicoproteína de la Espiga del Coronavirus/genética , Vacunas Sintéticas/inmunología , Vacunas Sintéticas/farmacología , Células Vero , Carga Viral , Adulto Joven
15.
Science ; 370(6520): 1089-1094, 2020 11 27.
Artículo en Inglés | MEDLINE | ID: mdl-33082295

RESUMEN

Vaccine efforts to combat the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the current coronavirus disease 2019 (COVID-19) pandemic, are focused on SARS-CoV-2 spike glycoprotein, the primary target for neutralizing antibodies. We performed cryo-election microscopy and site-specific glycan analysis of one of the leading subunit vaccine candidates from Novavax, which is based on a full-length spike protein formulated in polysorbate 80 detergent. Our studies reveal a stable prefusion conformation of the spike immunogen with slight differences in the S1 subunit compared with published spike ectodomain structures. We also observed interactions between the spike trimers, allowing formation of higher-order spike complexes. This study confirms the structural integrity of the full-length spike protein immunogen and provides a basis for interpreting immune responses to this multivalent nanoparticle immunogen.


Asunto(s)
Vacunas contra la COVID-19/química , Glicoproteína de la Espiga del Coronavirus/química , Microscopía por Crioelectrón , Humanos , Dominios Proteicos , Multimerización de Proteína
16.
Vaccines (Basel) ; 8(4)2020 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-33066540

RESUMEN

Human respiratory syncytial virus (RSV) is a cause of lower respiratory tract infection in infants, young children, and older adults. There is no licensed vaccine and prophylactic treatment options are limited. The RSV fusion (F) glycoprotein is a target of host immunity and thus a focus for vaccine development. F-trimers are metastable and undergo significant rearrangements from the prefusion to a stable postfusion structure with neutralizing epitopes on intermediate structures. We hypothesize that vaccine strategies that recapitulate the breathable F quaternary structure, and provide accessibility of B-cells to epitopes on intermediate conformations, may collectively contribute to protective immunity, while rigid prefusion F structures restrict access to key protective epitopes. To test this hypothesis, we used the near full-length prefusogenic F as a backbone to construct three prefusion F variants with substitutions in the hydrophobic head cavity: (1) disulfide bond mutant (DS), (2) space filling hydrophobic amino acid substitutions (Cav1), and (3) DS, Cav1 double mutant (DS-Cav1). In this study, we compared the immunogenicity of prefusogenic F to prefusion F variants in two animal models. Native prefusogenic F was significantly more immunogenic, producing high titer antibodies to prefusogenic, prefusion, and postfusion F structures, while animals immunized with DS or DS-Cav1 produced antibodies to prefusion F. Importantly, prefusogenic F elicited antibodies that target neutralizing epitopes including prefusion-specific site zero (Ø) and V and conformation-independent neutralizing sites II and IV. Immunization with DS or DS-Cav1 elicited antibodies primarily to prefusion-specific sites Ø and V with little or no antibodies to other key neutralizing sites. Animals immunized with prefusogenic F also had significantly higher levels of antibodies that cross-neutralized RSV A and B subtypes, while immunization with DS or DS-Cav1 produced antibodies primarily to the A subtype. We conclude that breathable trimeric vaccines that closely mimic the native F-structure, and incorporate strategies for B-cell accessibility to protective epitopes, are important considerations for vaccine design. F structures locked in a single conformation restrict access to neutralizing epitopes that may collectively contribute to destabilizing F-trimers important for broad protection. These results also have implications for vaccine strategies targeting other type 1 integral membrane proteins.

17.
bioRxiv ; 2020 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-32793901

RESUMEN

Vaccine efforts against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) responsible for the current COVID-19 pandemic are focused on SARS-CoV-2 spike glycoprotein, the primary target for neutralizing antibodies. Here, we performed cryo-EM and site-specific glycan analysis of one of the leading subunit vaccine candidates from Novavax based on a full-length spike protein formulated in polysorbate 80 (PS 80) detergent. Our studies reveal a stable prefusion conformation of the spike immunogen with slight differences in the S1 subunit compared to published spike ectodomain structures. Interestingly, we also observed novel interactions between the spike trimers allowing formation of higher order spike complexes. This study confirms the structural integrity of the full-length spike protein immunogen and provides a basis for interpreting immune responses to this multivalent nanoparticle immunogen.

18.
Vaccines (Basel) ; 8(1)2020 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-32098409

RESUMEN

Influenza vaccine effectiveness varies annually due to the fast evolving seasonal influenza A(H3N2) strain and egg-derived mutations-both of which can cause a mismatch between the vaccine and circulating strains. To address these limitations, we have developed a hemagglutinin (HA)-based protein-detergent nanoparticle influenza vaccine (NIV) with a saponin-based Matrix-M™ adjuvant. In a phase 1 clinical trial of older adults, the vaccine demonstrated broadly cross-reactive A(H3N2) HA antibody responses. Two broadly neutralizing monoclonal antibodies derived from NIV-immunized mice were characterized by transmission electron microscopy (TEM), antibody competition assays, fluorescence-activated cell sorting (FACS) analysis, and protein-protein docking. These antibodies recognize two conserved regions of the head domain, namely the receptor binding site and the vestigial esterase subdomain, thus demonstrating the potential for an HA subunit vaccine to elicit antibodies targeting structurally and antigenically distinct but conserved sites. Antibody competition studies with sera from the phase 1 trial in older adults confirmed that humans also make antibodies to these two head domains and against the highly conserved stem domain. This data supports the potential of an adjuvanted recombinant HA nanoparticle vaccine to induce broadly protective immunity and improved vaccine efficacy.

19.
Vaccine ; 38(5): 1258-1270, 2020 01 29.
Artículo en Inglés | MEDLINE | ID: mdl-31761502

RESUMEN

Globally, human respiratory syncytial virus (RSV) is a major cause of severe lower respiratory infection in infants and young children. There are no licensed vaccines despite the high worldwide disease burden. RSV fusion (F) glycoprotein vaccine is the most advanced candidate for maternal immunization. In this report, a baboon maternal immunization model was used to assess the immunogenicity and protection of infants against pulmonary challenge with human RSV/A. Vaccination in the third trimester produced high anti-RSV F IgG titers and virus-neutralizing antibodies. Infants born to immunized females had high levels of serum RSV antibodies that were comparable to maternal levels at birth and persisted for over 50 days with a half-life of 14-24 days. Furthermore, infants from immunized females and challenged with RSV/A were healthy, developed less severe disease, and had only mild pulmonary inflammatory changes whereas infants born to non-vaccinated females developed more severe disease with marked to moderate interstitial pneumonia, pulmonary edema, and bronchiolar obstruction. These results support the further development of the RSV F vaccine for maternal immunization.


Asunto(s)
Glicoproteínas/inmunología , Infecciones por Virus Sincitial Respiratorio , Vacunas contra Virus Sincitial Respiratorio/administración & dosificación , Proteínas Virales de Fusión/inmunología , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Femenino , Glicoproteínas/administración & dosificación , Madres , Papio , Infecciones por Virus Sincitial Respiratorio/prevención & control , Virus Sincitial Respiratorio Humano/inmunología , Vacunación , Proteínas Virales de Fusión/administración & dosificación
20.
Vaccine ; 37(42): 6134-6138, 2019 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-31492474

RESUMEN

dscCfaE is a recombinant form of the CFA/I tip adhesin CfaE, expressed by a large proportion of enterotoxigenic E. coli (ETEC). It is highly immunogenic by the intranasal route in mice and Aotus nancymaae, protective against challenge with CFA/I+ ETEC in an A. nancymaae challenge model, and antibodies to dscCfaE passively protect against CFA/I+ ETEC challenge in human volunteers. Here, we show that transcutaneous immunization (TCI) with dscCfaE in mice resulted in strong anti-CfaE IgG serum responses, with a clear dose-response effect. Co-administration with heat-labile enterotoxin (LT) resulted in enhanced immune responses over those elicited by dscCfaE alone and strong anti-LT antibody responses. The highest dose of dscCfaE administered transcutaneously with LT elicited strong HAI titers, a surrogate for the neutralization of intestinal adhesion. Fecal anti-adhesin IgG and IgA antibody responses were also induced. These findings support the feasibility of TCI for the application of an adhesin-toxin based ETEC vaccine.


Asunto(s)
Toxinas Bacterianas/inmunología , Escherichia coli Enterotoxigénica/inmunología , Enterotoxinas/inmunología , Proteínas de Escherichia coli/inmunología , Vacunas contra Escherichia coli/inmunología , Proteínas Fimbrias/inmunología , Vacunación/métodos , Adhesinas de Escherichia coli/inmunología , Administración Cutánea , Animales , Femenino , Inmunoglobulina A/sangre , Inmunoglobulina A/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Ratones , Ratones Endogámicos BALB C , Proteínas Recombinantes/inmunología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA