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A singleton fetus was referred to fetal magnetic resonance imaging (MRI) at 25 weeks due to mild ventriculomegaly and an abnormal fetal echocardiogram showing cardiomegaly, right ventricular hypertrophy and tricuspid insufficiency. Patchy areas of ischemic infarction, extensive subacute and chronic hemorrhage not respecting vascular territories, encephaloclastic cysts and closed lip schizencephaly were identified. Cataract was detected postnatally. The anomalies were caused by a pathogenic mutation (c.353 G>A; p.G118D) in the COL4A1 gene. The phenotype seen in this case, i.e. small vessel cerebral disease with or without ocular anomalies caused by COL4A1 mutations, is likely an underrecognized cause of perinatal stroke. The pattern of abnormalities reported herein should prompt strong consideration for diagnosis and molecular testing.
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Colágeno Tipo IV , Accidente Cerebrovascular , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Colágeno Tipo IV/genética , Colágeno Tipo IV/metabolismo , Femenino , Humanos , Imagen por Resonancia Magnética , Mutación , Embarazo , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/genéticaRESUMEN
Affinity- and stability-engineered variants of CTLA4-Ig fusion molecules with enhanced pharmacokinetic profiles could yield improved therapies with the potential of higher efficacy and greater convenience to patients. In this study, to our knowledge, we have, for the first time, used in vitro evolution to simultaneously optimize CTLA4 affinity and stability. We selected for improved binding to both ligands, CD80 and CD86, and screened as dimeric Fc fusions directly in functional assays to identify variants with stronger suppression of in vitro T cell activation. The majority of CTLA4 molecules showing the largest potency gains in primary in vitro and ex vivo human cell assays, using PBMCs from type 1 diabetes patients, had significant improvements in CD80, but only modest gains in CD86 binding. We furthermore observed different potency rankings between our lead molecule MEDI5265, abatacept, and belatacept, depending on which type of APC was used, with MEDI5265 consistently being the most potent. We then created fusions of both stability- and potency-optimized CTLA4 moieties with human Fc variants conferring extended plasma t1/2 In a cynomolgus model of T cell-dependent Ab response, the CTLA4-Ig variant MEDI5265 could be formulated at >100 mg/ml for s.c. administration and showed superior efficacy and significantly prolonged serum t1/2 The combination of higher stability and potency with prolonged pharmacokinetics could be compatible with very infrequent, s.c. dosing while maintaining a similar level of immune suppression to more frequently and i.v. administered licensed therapies.
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Abatacept/farmacología , Diseño de Fármacos , Inmunosupresores/farmacología , Abatacept/química , Animales , Antígeno B7-1/inmunología , Antígeno B7-2 , Estabilidad de Medicamentos , Humanos , Inmunosupresores/química , Unión Proteica/inmunologíaRESUMEN
Interleukin (IL)-33 is a broad-acting alarmin cytokine that can drive inflammatory responses following tissue damage or infection and is a promising target for treatment of inflammatory disease. Here, we describe the identification of tozorakimab (MEDI3506), a potent, human anti-IL-33 monoclonal antibody, which can inhibit reduced IL-33 (IL-33red) and oxidized IL-33 (IL-33ox) activities through distinct serum-stimulated 2 (ST2) and receptor for advanced glycation end products/epidermal growth factor receptor (RAGE/EGFR complex) signalling pathways. We hypothesized that a therapeutic antibody would require an affinity higher than that of ST2 for IL-33, with an association rate greater than 107 M-1 s-1, to effectively neutralize IL-33 following rapid release from damaged tissue. An innovative antibody generation campaign identified tozorakimab, an antibody with a femtomolar affinity for IL-33red and a fast association rate (8.5 × 107 M-1 s-1), which was comparable to soluble ST2. Tozorakimab potently inhibited ST2-dependent inflammatory responses driven by IL-33 in primary human cells and in a murine model of lung epithelial injury. Additionally, tozorakimab prevented the oxidation of IL-33 and its activity via the RAGE/EGFR signalling pathway, thus increasing in vitro epithelial cell migration and repair. Tozorakimab is a novel therapeutic agent with a dual mechanism of action that blocks IL-33red and IL-33ox signalling, offering potential to reduce inflammation and epithelial dysfunction in human disease.
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Inflamación , Proteína 1 Similar al Receptor de Interleucina-1 , Ratones , Humanos , Animales , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Inflamación/metabolismo , Interleucina-33/metabolismo , Citocinas/metabolismo , Receptores ErbB/metabolismo , Transducción de SeñalRESUMEN
Catastrophic bleeding is a feared complication of robotic abdominal procedures that involve dissection in close proximity to major vessels. In the event of uncontrollable hemorrhage, standard practice involves emergency undocking with conversion to laparotomy. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a rapid and life-saving technique gaining acceptance in the trauma setting for the management of catastrophic hemorrhage. The purpose of this study was to evaluate feasibility of REBOA for emergency hemostasis during robotic surgery. The surgical robot was docked to a REBOA mannequin to simulate an upper abdominal surgery. A femoral arterial line was placed in the mannequin. Supplies needed for REBOA insertion were opened and arranged on the surgical back table. The surgeon was seated at the console with an assistant scrubbed. A catastrophic vascular injury was announced. The time it took the surgeon to achieve aortic occlusion by the REBOA was recorded. Four surgeons participated and performed three timed trials each. Each surgeon, irrespective of experience with REBOA or years in surgical practice, was able to obtain aortic occlusion in less than 2 min. The mean time to aortic occlusion for all surgeons was 111 s. No manipulation of the robotic arms was required to perform the procedure. Aortic occlusion was achieved rapidly with REBOA. Ability to achieve prompt aortic control was not associated with surgical experience or prior familiarity with the REBOA device. Prophylactic femoral access and preparation of supplies facilitates prompt placement of the occlusion balloon. REBOA should be considered as a viable alternative to open laparotomy for temporary hemorrhage control during robotic surgery.
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Abdomen/cirugía , Aorta , Oclusión con Balón/métodos , Hemorragia/etiología , Hemorragia/terapia , Complicaciones Intraoperatorias/etiología , Complicaciones Intraoperatorias/terapia , Procedimientos Quirúrgicos Robotizados/efectos adversos , Entrenamiento Simulado/métodos , Oclusión con Balón/instrumentación , Urgencias Médicas , Estudios de Factibilidad , Humanos , Maniquíes , Índice de Severidad de la EnfermedadRESUMEN
Protein biopharmaceuticals are highly successful, but their utility is compromised by their propensity to aggregate during manufacture and storage. As aggregation can be triggered by non-native states, whose population is not necessarily related to thermodynamic stability, prediction of poorly-behaving biologics is difficult, and searching for sequences with desired properties is labour-intensive and time-consuming. Here we show that an assay in the periplasm of E. coli linking aggregation directly to antibiotic resistance acts as a sensor for the innate (un-accelerated) aggregation of antibody fragments. Using this assay as a directed evolution screen, we demonstrate the generation of aggregation resistant scFv sequences when reformatted as IgGs. This powerful tool can thus screen and evolve 'manufacturable' biopharmaceuticals early in industrial development. By comparing the mutational profiles of three different immunoglobulin scaffolds, we show the applicability of this method to investigate protein aggregation mechanisms important to both industrial manufacture and amyloid disease.
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Agregado de Proteínas , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Regiones Determinantes de Complementariedad/química , Escherichia coli/metabolismo , Humanos , Inmunoglobulina G/química , Viabilidad Microbiana , Mutación/genética , Anticuerpos de Cadena Única/química , beta-Lactamasas/químicaRESUMEN
BACKGROUND: The development of early intervention services for young people with first-episode psychosis is a priority internationally. AIMS: To evaluate the development, implementation and impact of existing and newly formed early intervention services in England. METHOD: Multiple-case study involving staff, users, carers and commissioners of 14 early intervention services. RESULTS: Service numbers increased in response to national policy directives. They were still actively working with 90.6% of service users 12 months after inception. They were highly valued by users and carers as providing a personal service that contrasted with previous experiences of care. Tensions between providing a quality service and meeting case-load targets linked to future funding led teams to adopt a series of survival strategies with some unintended consequences. CONCLUSIONS: Early intervention services are highly valued by consumers and engage users effectively after 12 months. Implementation of these services is threatened unless sufficient consistent funding is made available.
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Servicios de Salud del Adolescente/organización & administración , Atención a la Salud/organización & administración , Servicios de Salud Mental/organización & administración , Trastornos Psicóticos/terapia , Adolescente , Adulto , Anciano , Actitud del Personal de Salud , Femenino , Humanos , Entrevistas como Asunto , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Aceptación de la Atención de Salud , Reino Unido , Adulto JovenRESUMEN
BACKGROUND: Colon cancer is the third most frequent cancer diagnosis, and primary payer status has been shown to be associated with treatment modalities and survival in cancer patients. The goal of our study was to determine the between-insurance differences in survival in patients with clinical stage III colon cancer using data from the National Cancer Database (NCDB). MATERIALS AND METHODS: We identified 130,998 patients with clinical stage III colon cancer in the NCDB diagnosed from 2004 to 2012. Kaplan-Meier curves and multivariable Cox regression models were used to determine the association between insurance status and survival. RESULTS: Patients with private insurance plans were 28%, 30%, and 16% less likely to die than were uninsured patients, Medicaid recipients, and Medicare beneficiaries, respectively. Medicare patients were 14% were less likely to die compared with uninsured patients. Patients receiving chemotherapy were, on average, 65% less likely to die compared with the patients not receiving chemotherapy. CONCLUSION: Private insurance and a greater socioeconomic status were associated with increased patient survival compared with other insurance plans or the lack of insurance. Future research should continue to unravel how socioeconomic status and insurance status contribute to the quality of care and survival of oncologic patients.
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Neoplasias del Colon/economía , Neoplasias del Colon/mortalidad , Bases de Datos Factuales , Cobertura del Seguro/economía , Seguro de Salud/economía , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias del Colon/patología , Neoplasias del Colon/terapia , Femenino , Estudios de Seguimiento , Humanos , Masculino , Medicaid , Pacientes no Asegurados , Medicare , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Retrospectivos , Tasa de Supervivencia , Estados UnidosRESUMEN
Ion channels play crucial roles in physiology by modulation of cellular functions that include electrical excitability, secretion, cell migration, and gene transcription. They are an important target class for drug discovery and have historically been targeted using small molecule approaches. A significant opportunity exists to target these channels with antibodies and alternative forms of biologics. Antibodies display high specificity, selectivity, and affinity for their target antigen, thus having the potential to target ion channels very precisely. Nonetheless, isolating antibodies to ion channels is challenging due to the difficulties in expression and purification of ion channels in a format suitable for antibody drug discovery and due to the complexities of screening for function. In this overview, we focus on an array of screening methods, ranging from direct antibody binding screens to complex electrophysiological assays, and describe how these assays can be used to identify functional monoclonal antibodies. We also provide some insights into specific considerations which are required to enable these screens to be used for antibody drug discovery. © 2018 by John Wiley & Sons, Inc.
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Anticuerpos Monoclonales/fisiología , Canales Iónicos/fisiología , Animales , Antígenos/fisiología , Bioensayo , Descubrimiento de Drogas , HumanosRESUMEN
C5a is a potent anaphylatoxin that modulates inflammation through the C5aR1 and C5aR2 receptors. The molecular interactions between C5a-C5aR1 receptor are well defined, whereas C5a-C5aR2 receptor interactions are poorly understood. Here, we describe the generation of a human antibody, MEDI7814, that neutralizes C5a and C5adesArg binding to the C5aR1 and C5aR2 receptors, without affecting complement-mediated bacterial cell killing. Unlike other anti-C5a mAbs described, this antibody has been shown to inhibit the effects of C5a by blocking C5a binding to both C5aR1 and C5aR2 receptors. The crystal structure of the antibody in complex with human C5a reveals a discontinuous epitope of 22 amino acids. This is the first time the epitope for an antibody that blocks C5aR1 and C5aR2 receptors has been described, and this work provides a basis for molecular studies aimed at further understanding the C5a-C5aR2 receptor interaction. MEDI7814 has therapeutic potential for the treatment of acute inflammatory conditions in which both C5a receptors may mediate inflammation, such as sepsis or renal ischemia-reperfusion injury.
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Anticuerpos Monoclonales/farmacología , Afinidad de Anticuerpos , Complemento C5a/antagonistas & inhibidores , Receptor de Anafilatoxina C5a/antagonistas & inhibidores , Receptores de Quimiocina/antagonistas & inhibidores , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/genética , Anticuerpos Monoclonales/inmunología , Especificidad de Anticuerpos , Sitios de Unión de Anticuerpos , Complemento C5a/química , Complemento C5a/inmunología , Complemento C5a/metabolismo , Mapeo Epitopo/métodos , Epítopos , Células HEK293 , Humanos , Unión Proteica , Conformación Proteica , Ingeniería de Proteínas , Receptor de Anafilatoxina C5a/química , Receptor de Anafilatoxina C5a/inmunología , Receptor de Anafilatoxina C5a/metabolismo , Receptores de Quimiocina/química , Receptores de Quimiocina/inmunología , Receptores de Quimiocina/metabolismo , Relación Estructura-ActividadRESUMEN
BACKGROUND: Primary care mental health workers are a new role recently introduced into primary care in England to help manage patients with common mental health problems. AIM: To explore the views of GPs, primary care teams and patients on the value and development of the new role of primary care mental health workers in practice. DESIGN OF STUDY: Qualitative study. SETTING: The Heart of Birmingham Primary Care Teaching Trust in the West Midlands, UK. METHOD: Thirty-seven semi-structured interviews involving seven primary care mental health workers, 21 patients and 11 focus groups involving 38 members of primary care teams were held with six teams with a worker. Two teams asked for the worker to be removed. Six practice managers also took part in the study. RESULTS: A number of different approaches were used to implement this new role. Strategies that incorporated the views of primary care trust senior management, primary care teams and workers' views appeared most successful. Rapid access to a healthcare professional at times of stress and the befriending role of the worker were also highly valued. Workers felt that their role left them professionally isolated at times. A number of workers described tension around ownership of the role. CONCLUSION: Primary care mental health workers appear to provide a range of skills valued by patients and the primary care teams and can increase patient access and choice in this area of health care. Successful implementation strategies highlighted in this study may be generalisable to other new roles in primary care.
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Actitud del Personal de Salud , Servicios Comunitarios de Salud Mental/organización & administración , Medicina Familiar y Comunitaria/organización & administración , Trastornos Mentales/terapia , Rol Profesional , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Investigación CualitativaRESUMEN
BACKGROUND: Mental health issues are a core part of the work of primary care and are the second most common reason for consultations. There is some evidence that the quality of primary care mental health provision is variable. AIM: To evaluate the effectiveness of primary care mental health workers with regards to satisfaction with care, mental health symptoms, use of the voluntary sector, and cost effectiveness of care. DESIGN OF STUDY: Cluster randomised controlled trial. SETTING: Practices in the Heart of Birmingham Primary Care Trust, Birmingham, England. METHOD: Nineteen practices and 368 patients (18 to 65 years of age) with a diagnosis of a new or ongoing common mental health problem were recruited. Sixteen practices and 284 patients completed the trial. RESULTS: Patients in intervention practices had a higher mean level of general satisfaction than those in control practices (difference between group scores of 8.3, 95% confidence interval = 1.3 to 15.3, P = 0.023). The two groups did not differ in mental health symptom scores or use of the voluntary sector. CONCLUSION: For patients with common mental health problems, primary care mental health workers may be effective at increasing satisfaction with an episode of care.
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Servicios Comunitarios de Salud Mental/normas , Trastornos Mentales/terapia , Satisfacción del Paciente , Calidad de la Atención de Salud/normas , Adolescente , Adulto , Anciano , Análisis por Conglomerados , Servicios Comunitarios de Salud Mental/economía , Análisis Costo-Beneficio , Femenino , Humanos , Masculino , Trastornos Mentales/economía , Trastornos Mentales/psicología , Persona de Mediana Edad , Calidad de la Atención de Salud/economía , Resultado del TratamientoRESUMEN
BACKGROUND: Patient involvement in health care is a strong political driver in the NHS. However in spite of policy prominence, there has been only limited previous work exploring patient involvement for people with serious mental illness. AIM: To describe the views on, potential for, and types of patient involvement in primary care from the perspectives of primary care health professionals and patients with serious mental illness. DESIGN OF STUDY: Qualitative study consisting of six patient, six health professional and six combined focus groups between May 2002 and January 2003. SETTING: Six primary care trusts in the West Midlands, England. METHOD: Forty-five patients with serious mental illness, 39 GPs, and eight practice nurses participated in a series of 18 focus groups. All focus groups were audiotaped and fully transcribed. Nvivo was used to manage data more effectively. RESULTS: Most patients felt that only other people with lived experience of mental illness could understand what they were going through. This experience could be used to help others navigate the health- and social-care systems, give advice about medication, and offer support at times of crisis. Many patients also saw paid employment within primary care as a way of addressing issues of poverty and social exclusion. Health professionals were, however, more reluctant to see patients as partners, be it in the consultation or in service delivery. CONCLUSIONS: Meaningful change in patient involvement requires commitment and belief from primary care practitioners that the views and experiences of people with serious mental illness are valid and valuable.
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Trastornos Mentales/psicología , Participación del Paciente/psicología , Adolescente , Adulto , Anciano , Actitud del Personal de Salud , Actitud Frente a la Salud , Toma de Decisiones , Medicina Familiar y Comunitaria , Femenino , Grupos Focales , Humanos , Masculino , Trastornos Mentales/terapia , Persona de Mediana EdadRESUMEN
Injectable biomaterials are defined as implantable materials that can be introduced into the body as a liquid and solidify in situ. Such materials offer the clinical advantages of being implanted minimally invasively and easily forming space-filling solids in irregularly shaped defects. Injectable biomaterials have been widely investigated as scaffolds for tissue engineering. However, for the repair of certain load-bearing areas in the body, such as the intervertebral disc, scaffolds should possess adhesive properties. This will minimize the risk of dislocation during motion and ensure intimate contact with the surrounding tissue, providing adequate transmission of forces. Here, we describe the preparation and characterization of a scaffold composed of thermally sensitive poly(N-isopropylacrylamide)-graft-chondroitin sulfate (PNIPAAM-g-CS) and alginate microparticles. The PNIPAAm-g-CS copolymer forms a viscous solution in water at RT, into which alginate particles are suspended to enhance adhesion. Above the lower critical solution temperature (LCST), around 30 °C, the copolymer forms a solid gel around the microparticles. We have adapted standard biomaterials characterization procedures to take into account the reversible phase transition of PNIPAAm-g-CS. Results indicate that the incorporation of 50 or 75 mg/ml alginate particles into 5% (w/v) PNIPAAm-g-CS solutions quadruple the adhesive tensile strength of PNIPAAm-gCS alone (p<0.05). The incorporation of alginate microparticles also significantly increases swelling capacity of PNIPAAm-g-CS (p<0.05), helping to maintain a space-filling gel within tissue defects. Finally, results of the in vitro toxicology assay kit, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) and Live/Dead viability assay indicate that the adhesive is capable of supporting the survival and proliferation of encapsulated Human Embryonic Kidney (HEK) 293 cells over 5 days.
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Resinas Acrílicas , Materiales Biocompatibles , Sulfatos de Condroitina , Ingeniería de Tejidos , Alginatos , Ácido Glucurónico , Células HEK293 , Ácidos Hexurónicos , Humanos , Polímeros , TemperaturaRESUMEN
Highly sensitive, high-throughput assay technologies are required for the identification of antibody therapeutics. Multiplexed assay systems are particularly advantageous because they allow evaluation of several parameters within 1 well, increasing throughput and reducing hands-on laboratory time. The mirrorball (TTP Labtech), using high-throughput fluorometric microvolume assay technology, offers simultaneous scanning with up to 3 lasers as well as laser scatter detection. This makes the mirrorball especially suitable for the development of highly sensitive and multiplexed assays. We have developed bead- and cell-based binding assays that demonstrate how the multilaser capability of the mirrorball can be exploited to enhance assay sensitivity. In addition, using the multilaser simultaneous scanning capability, we have established multiplexed cytokine quantitation assays and antibody-cell binding assays. Our results demonstrate the potential utility of this technology to improve the sensitivity and efficiency of biologics screening, resulting in streamlining of the lead antibody selection process.
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Anticuerpos/inmunología , Descubrimiento de Drogas , Células HEK293 , HumanosRESUMEN
BACKGROUND: In the general population the prevalence of bipolar and schizophrenia is 0.24% and 1.4% respectively. People with schizophrenia and bipolar disorder have a significantly reduced life expectancy, increased rates of unemployment and a fear of stigma leading to reduced self-confidence. A core outcome set is a standardised collection of items that should be reported in all controlled trials within a research area. There are currently no core outcome sets available for use in effectiveness trials involving bipolar or schizophrenia service users managed in a community setting. METHODS: A three-step approach is to be used to concurrently develop two core outcome sets, one for bipolar and one for schizophrenia. First, a comprehensive list of outcomes will be compiled through qualitative research and systematic searching of trial databases. Focus groups and one-to-one interviews will be completed with service users, carers and healthcare professionals. Second, a Delphi study will be used to reduce the lists to a core set. The three-round Delphi study will ask service users to score the outcome list for relevance. In round two stakeholders will only see the results of their group, while in round three stakeholders will see the results of all stakeholder group by stakeholder group. Third, a consensus meeting with stakeholders will be used to confirm outcomes to be included in the core set. Following the development of the core set a systematic literature review of existing measures will allow recommendations for how the core outcomes should be measured and a stated preference survey will explore the strength of people's preferences and estimate weights for the outcomes that comprise the core set. DISCUSSION: A core outcome set represents the minimum measurement requirement for a research area. We aim to develop core outcome sets for use in research involving service users with schizophrenia or bipolar managed in a community setting. This will inform the wider PARTNERS2 study aims and objectives of developing an innovative primary care-based model of collaborative care for people with a diagnosis of bipolar or schizophrenia.
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Trastorno Bipolar/terapia , Protocolos Clínicos , Evaluación de Resultado en la Atención de Salud , Esquizofrenia/terapia , Técnica Delphi , Grupos Focales , Humanos , Investigación CualitativaRESUMEN
Immunization of mice or rats with a "non-self" protein is a commonly used method to obtain monoclonal antibodies, and relies on the immune system's ability to recognize the immunogen as foreign. Immunization of an antigen with 100% identity to the endogenous protein, however, will not elicit a robust immune response. To develop antibodies to mouse proteins, we focused on the potential for breaking such immune tolerance by genetically fusing two independent T-cell epitope-containing sequences (from tetanus toxin (TT) and diphtheria toxin fragment A (DTA)) to a mouse protein, mouse ST2 (mST2). Wild-type CD1 mice were immunized with three mST2 tagged proteins (Fc, TT and DTA) and the specific serum response was determined. Only in mice immunized with the T-cell epitope-containing antigens were specific mST2 serum responses detected; hybridomas generated from these mice secreted highly sequence-diverse IgGs that were capable of binding mST2 and inhibiting the interaction of mST2 with its ligand, mouse interleukin (IL)-33 (mIL-33). Of the hundreds of antibodies profiled, we identified five potent antibodies that were able to inhibit IL-33 induced IL-6 release in a mast cell assay; notably one such antibody was sufficiently potent to suppress IL-5 release and eosinophilia infiltration in an Alternaria alternata challenge mouse model of asthma. This study demonstrated, for the first time, that T-cell epitope-containing tags have the ability to break tolerance in wild-type mice to 100% conserved proteins, and it provides a compelling argument for the broader use of this approach to generate antibodies against any mouse protein or conserved ortholog.
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Anticuerpos Monoclonales de Origen Murino/inmunología , Especificidad de Anticuerpos , Epítopos de Linfocito T/inmunología , Receptores de Interleucina/inmunología , Animales , Anticuerpos Monoclonales de Origen Murino/farmacología , Asma/tratamiento farmacológico , Asma/inmunología , Asma/patología , Línea Celular Transformada , Toxina Diftérica/química , Toxina Diftérica/inmunología , Epítopos de Linfocito T/química , Femenino , Humanos , Proteína 1 Similar al Receptor de Interleucina-1 , Ratones , Ratones Endogámicos BALB C , Ratas , Receptores de Interleucina/química , Toxina Tetánica/química , Toxina Tetánica/inmunologíaRESUMEN
In response to infections and irritants, the respiratory epithelium releases the alarmin interleukin (IL)-33 to elicit a rapid immune response. However, little is known about the regulation of IL-33 following its release. Here we report that the biological activity of IL-33 at its receptor ST2 is rapidly terminated in the extracellular environment by the formation of two disulphide bridges, resulting in an extensive conformational change that disrupts the ST2 binding site. Both reduced (active) and disulphide bonded (inactive) forms of IL-33 can be detected in lung lavage samples from mice challenged with Alternaria extract and in sputum from patients with moderate-severe asthma. We propose that this mechanism for the rapid inactivation of secreted IL-33 constitutes a 'molecular clock' that limits the range and duration of ST2-dependent immunological responses to airway stimuli. Other IL-1 family members are also susceptible to cysteine oxidation changes that could regulate their activity and systemic exposure through a similar mechanism.
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Asma/inmunología , Interleucina-33/metabolismo , Receptores de Superficie Celular/inmunología , Receptores de Interleucina/inmunología , Animales , Asma/genética , Asma/metabolismo , Humanos , Proteína 1 Similar al Receptor de Interleucina-1 , Interleucina-33/genética , Interleucina-33/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Oxidación-Reducción , Receptores de Superficie Celular/genética , Receptores de Interleucina/genéticaAsunto(s)
Accesibilidad a los Servicios de Salud/normas , Trastornos Mentales , Servicios de Salud Mental , Salud Mental , Planificación de Atención al Paciente/organización & administración , Mejoramiento de la Calidad/organización & administración , Adolescente , Niño , Análisis Costo-Beneficio , Política de Salud , Humanos , Trastornos Mentales/economía , Trastornos Mentales/terapia , Salud Mental/economía , Salud Mental/normas , Servicios de Salud Mental/economía , Servicios de Salud Mental/organización & administración , Servicios de Salud Mental/normas , Reino Unido , Listas de EsperaRESUMEN
The critical role played by IgE in allergic asthma is well-documented and clinically precedented, but some patients in whom IgE neutralization may still offer clinical benefit are excluded from treatment with the existing anti-IgE therapy, omalizumab, due to high total IgE levels or body mass. In this study, we sought to generate a novel high affinity anti-IgE antibody (MEDI4212) with potential to treat a broad severe asthma patient population. Analysis of body mass, total and allergen-specific IgE levels in a cohort of severe asthmatics was used to support the rationale for development of a high affinity IgE-targeted antibody therapeutic. Phage display technology was used to generate a human IgG1 lead antibody, MEDI4212, which was characterized in vitro using binding, signaling and functional assay systems. Protein crystallography was used to determine the details of the interaction between MEDI4212 and IgE. MEDI4212 bound human IgE with an affinity of 1.95 pM and was shown to target critical residues in the IgE Cε3 domain critical for interaction with FcεRI. MEDI4212 potently inhibited responses through FcεRI and also prevented the binding of IgE to CD23. When used ex vivo at identical concentration, MEDI4212 depleted free-IgE from human sera to levels ~1 log lower than omalizumab. Our results thus indicate that MEDI4212 is a novel, high affinity antibody that binds specifically to IgE and prevents IgE binding to its receptors. MEDI4212 effectively depleted free-IgE from human sera ex vivo to a level (1 IU/mL) anticipated to provide optimal IgE suppression in severe asthma patients.