RESUMEN
Increased immune evasion by SARS-CoV-2 variants of concern highlights the need for new therapeutic neutralizing antibodies. Immunization with nanoparticles co-displaying spike receptor-binding domains (RBDs) from eight sarbecoviruses (mosaic-8 RBD-nanoparticles) efficiently elicits cross-reactive polyclonal antibodies against conserved sarbecovirus RBD epitopes. Here, we identified monoclonal antibodies (mAbs) capable of cross-reactive binding and neutralization of animal sarbecoviruses and SARS-CoV-2 variants by screening single mouse B cells secreting IgGs that bind two or more sarbecovirus RBDs. Single-particle cryo-EM structures of antibody-spike complexes, including a Fab-Omicron complex, mapped neutralizing mAbs to conserved class 1/4 RBD epitopes. Structural analyses revealed neutralization mechanisms, potentials for intra-spike trimer cross-linking by IgGs, and induced changes in trimer upon Fab binding. In addition, we identified a mAb-resembling Bebtelovimab, an EUA-approved human class 3 anti-RBD mAb. These results support using mosaic RBD-nanoparticle vaccination to generate and identify therapeutic pan-sarbecovirus and pan-variant mAbs.
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COVID-19 , Nanopartículas , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo , Ratones , Animales , Humanos , SARS-CoV-2 , Epítopos , Glicoproteína de la Espiga del Coronavirus , Anticuerpos Monoclonales , Pruebas de Neutralización , Anticuerpos Antivirales , Anticuerpos NeutralizantesRESUMEN
Dopamine (DA) plays multiple roles in a wide range of physiological and pathological processes via a large network of dopaminergic projections. To dissect the spatiotemporal dynamics of DA release in both dense and sparsely innervated brain regions, we developed a series of green and red fluorescent G-protein-coupled receptor activation-based DA (GRABDA) sensors using a variety of DA receptor subtypes. These sensors have high sensitivity, selectivity and signal-to-noise ratio with subsecond response kinetics and the ability to detect a wide range of DA concentrations. We then used these sensors in mice to measure both optogenetically evoked and behaviorally relevant DA release while measuring neurochemical signaling in the nucleus accumbens, amygdala and cortex. Using these sensors, we also detected spatially resolved heterogeneous cortical DA release in mice performing various behaviors. These next-generation GRABDA sensors provide a robust set of tools for imaging dopaminergic activity under a variety of physiological and pathological conditions.
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Dopamina , Núcleo Accumbens , Ratones , Animales , Núcleo Accumbens/fisiología , Receptores Dopaminérgicos , Encéfalo , Receptores Acoplados a Proteínas GRESUMEN
Norrin/Frizzled4 (Fz4) signaling activates the canonical Wnt pathway to control retinal vascular development. Using genetically engineered mice, we show that precocious Norrin production leads to premature retinal vascular invasion and delayed Norrin production leads to characteristic defects in intraretinal vascular architecture. In genetic mosaics, wild-type endothelial cells (ECs) instruct neighboring Fz4(-/-) ECs to produce an architecturally normal mosaic vasculature, a cell nonautonomous effect. However, over the ensuing weeks, Fz4(-/-) ECs are selectively eliminated from the mosaic vasculature, implying the existence of a quality control program that targets defective ECs. In the adult retina and cerebellum, gain or loss of Norrin/Fz4 signaling results in a cell-autonomous gain or loss, respectively, of blood retina barrier and blood brain barrier function, indicating an ongoing requirement for Frizzled signaling in barrier maintenance and substantial plasticity in mature CNS vascular structure.
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Barrera Hematoencefálica , Barrera Hematorretinal , Células Endoteliales/metabolismo , Proteínas del Ojo/metabolismo , Receptores Frizzled/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Retina/metabolismo , Transducción de Señal , Animales , Movimiento Celular , Proliferación Celular , Células Endoteliales/citología , Proteínas del Ojo/genética , Receptores Frizzled/genética , Humanos , Ratones , Mosaicismo , Proteínas del Tejido Nervioso/genética , Plasticidad Neuronal , Retina/citología , Retina/embriología , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Human metapneumovirus (HMPV) is an important cause of acute lower respiratory infection in children and adults worldwide. There are four genetic subgroups of HMPV and both neutralizing antibodies and T cells contribute to protection. However, little is known about mechanisms of pathogenesis and most published work is based on a few extensively passaged, laboratory-adapted strains of HMPV. In this study, we isolated and characterized a panel of low passage HMPV clinical isolates representing all four genetic subgroups. The clinical isolates exhibited lower levels of in vitro replication compared to a lab-adapted strain. We compared disease phenotypes using a well-established mouse model. Several virulent isolates caused severe weight loss, lung pathology, airway dysfunction, and fatal disease in mice, which was confirmed in three inbred mouse strains. Disease severity did not correlate with lung viral titer, as virulent strains exhibited restricted replication in the lower airway. Virulent HMPV isolates were associated with markedly increased proinflammatory cytokine production and neutrophil influx; however, depletion of neutrophils or genetic ablation of inflammasome components did not reverse disease. Virulent clinical isolates induced markedly increased type I and type III interferon (IFN) secretion in vitro and in vivo. STAT1/2-deficient mice lacking both type I and type III IFN signaling showed reduced disease severity and increased lung viral replication. Inhibition of type I IFN signaling using a blocking antibody or genetic ablation of the type I IFN receptor reduced pathology with minimal effect on viral replication. Conversely, blockade of type III IFN signaling with a neutralizing antibody or genetic ablation of the IFN-lambda receptor had no effect on pathogenesis but restored viral replication. Collectively, these results demonstrate distinct roles for type I and type III IFN in HMPV pathogenesis and immunity.
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Metapneumovirus , Infecciones por Paramyxoviridae , Infecciones del Sistema Respiratorio , Niño , Animales , Ratones , Humanos , Interferón lambda , Pulmón , Infecciones del Sistema Respiratorio/patología , InterferonesRESUMEN
ABSTRACT: Treatment resistance of leukemia stem cells (LSCs) and suppression of the autologous immune system represent major challenges to achieve a cure in acute myeloid leukemia (AML). Although AML blasts generally retain high levels of surface CD38 (CD38pos), LSCs are frequently enriched in the CD34posCD38neg blast fraction. Here, we report that interferon gamma (IFN-γ) reduces LSCs clonogenic activity and induces CD38 upregulation in both CD38pos and CD38neg LSC-enriched blasts. IFN-γ-induced CD38 upregulation depends on interferon regulatory factor 1 transcriptional activation of the CD38 promoter. To leverage this observation, we created a novel compact, single-chain CD38-CD3 T-cell engager (BN-CD38) designed to promote an effective immunological synapse between CD38pos AML cells and both CD8pos and CD4pos T cells. We demonstrate that BN-CD38 engages autologous CD4pos and CD8pos T cells and CD38pos AML blasts, leading to T-cell activation and expansion and to the elimination of leukemia cells in an autologous setting. Importantly, BN-CD38 engagement induces the release of high levels of IFN-γ, driving the expression of CD38 on CD34posCD38neg LSC-enriched blasts and their subsequent elimination. Critically, although BN-CD38 showed significant in vivo efficacy across multiple disseminated AML cell lines and patient-derived xenograft models, it did not affect normal hematopoietic stem cell clonogenicity and the development of multilineage human immune cells in CD34pos humanized mice. Taken together, this study provides important insights to target and eliminate AML LSCs.
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Interferón gamma , Leucemia Mieloide Aguda , Linfocitos T , Animales , Humanos , Ratones , ADP-Ribosil Ciclasa 1/inmunología , ADP-Ribosil Ciclasa 1/metabolismo , Antígenos CD34/metabolismo , Línea Celular Tumoral , Células Madre Hematopoyéticas/metabolismo , Interferón gamma/efectos de los fármacos , Interferón gamma/metabolismo , Leucemia Mieloide Aguda/metabolismo , Células Madre Neoplásicas/metabolismo , Glicoproteínas de Membrana/inmunología , Glicoproteínas de Membrana/metabolismo , Linfocitos T/inmunología , Linfocitos T/metabolismo , Activación de Linfocitos/efectos de los fármacosRESUMEN
Over the past 3 decades, a diverse collection of small protein domains have been used as scaffolds to generate general purpose protein-binding reagents using a variety of protein display and enrichment technologies. To expand the repertoire of scaffolds and protein surfaces that might serve this purpose, we have explored the utility of (i) a pair of anti-parallel alpha-helices in a small highly disulfide-bonded 4-helix bundle, the CC4 domain from reversion-inducing Cysteine-rich Protein with Kazal Motifs and (ii) a concave beta-sheet surface and two adjacent loops in the human FN3 domain, the scaffold for the widely used monobody platform. Using M13 phage display and next generation sequencing, we observe that, in both systems, libraries of â¼30 million variants contain binding proteins with affinities in the low µM range for baits corresponding to the extracellular domains of multiple mammalian proteins. CC4- and FN3-based binding proteins were fused to the N- and/or C-termini of Fc domains and used for immunostaining of transfected cells. Additionally, FN3-based binding proteins were inserted into VP1 of AAV to direct AAV infection to cells expressing a defined surface receptor. Finally, FN3-based binding proteins were inserted into the Pvc13 tail fiber protein of an extracellular contractile injection system particle to direct protein cargo delivery to cells expressing a defined surface receptor. These experiments support the utility of CC4 helices B and C and of FN3 beta-strands C, D, and F together with adjacent loops CD and FG as surfaces for engineering general purpose protein-binding reagents.
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Biblioteca de Péptidos , Conformación Proteica en Hélice alfa , Conformación Proteica en Lámina beta , Animales , Humanos , Bacteriófago M13 , Técnicas de Visualización de Superficie Celular , Células HEK293 , Unión ProteicaRESUMEN
In central nervous system vascular endothelial cells, signaling via the partially redundant ligands WNT7A and WNT7B requires two co-activator proteins, GPR124 and RECK. WNT7A and RECK have been shown previously to play a role in limb development, but the mechanism of RECK action in this context is unknown. The roles of WNT7B and GPR124 in limb development have not been investigated. Using combinations of conventional and/or conditional loss-of-function alleles for mouse Wnt7a, Wnt7b, Gpr124 and Reck, including a Reck allele that codes for a protein that is specifically defective in WNT7A/WNT7B signaling, we show that reductions in ligand and/or co-activator function synergize to cause reduced and dysmorphic limb bone growth. Two additional limb phenotypes - loss of distal Lmx1b expression and ectopic growth of nail-like structures - occur with reduced Wnt7a/Wnt7b gene copy number and, respectively, with Reck mutations and with combined Reck and Gpr124 mutations. A third limb phenotype - bleeding into a digit - occurs with the most severe combinations of Wnt7a/Wnt7b, Reck and Gpr124 mutations. These data imply that the WNT7A/WNT7B-FRIZZLED-LRP5/LRP6-GPR124-RECK signaling system functions as an integral unit in limb development.
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Embrión de Mamíferos/metabolismo , Extremidades/embriología , Proteínas Ligadas a GPI/metabolismo , Receptores Acoplados a Proteínas G , Proteínas Wnt , Animales , Sistema Nervioso Central/metabolismo , Células Endoteliales/metabolismo , Ligandos , Ratones , Proteínas Proto-Oncogénicas/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Transducción de Señal , Proteínas Wnt/genética , Proteínas Wnt/metabolismoRESUMEN
Small hydrophobic (SH) proteins are a class of viral accessory proteins expressed by many members of the negative-stranded RNA viral families Paramyxoviridae and Pneumoviridae. Identified SH proteins are type I or II transmembrane (TM) proteins with a single-pass TM domain. Little is known about the functions of SH proteins; however, several possess viroporin activity, enhancing membrane permeability of infected cells or those expressing SH protein. Moreover, several SH proteins inhibit apoptosis and immune signaling pathways within infected cells, including TNF and interferon signaling, or activate inflammasomes. SH proteins are generally nonessential for viral replication in vitro, but loss of SH is often associated with reduced replication in vivo, suggesting a role in enhancing viral replication or evading host immunity. Analogous proteins are expressed by a variety of pathogens of public health importance; thus, understanding the functional importance and mechanisms of SH proteins provides insight into the pathogenesis and replication of negative-sense RNA viruses.
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Paramyxoviridae , Proteínas Virales , Replicación Viral , Humanos , Paramyxoviridae/metabolismo , Paramyxoviridae/fisiología , Proteínas Virales/metabolismo , Proteínas Virales/genética , Animales , Apoptosis , Pneumovirus/metabolismo , Pneumovirus/fisiología , Transducción de Señal , Proteínas Oncogénicas de RetroviridaeRESUMEN
Human metapneumovirus (HMPV) is a leading cause of respiratory infections in children, older adults, and those with underlying conditions (K. M. Edwards et al., N Engl J Med 368:633-643, 2013, https://doi.org/10.1056/NEJMoa1204630; A. R. Falsey et al., J Infect Dis 187:785-790, 2003, https://doi.org/10.1086/367901; J. S. Kahn, Clin Microbiol Rev 19:546-557, 2006, https://doi.org/10.1128/CMR.00014-06; N. Shafagati and J. Williams, F1000Res 7:135, 2018, https://doi.org/10.12688/f1000research.12625.1). HMPV must evade immune defenses to replicate successfully; however, the viral proteins used to accomplish this are poorly characterized. The HMPV small hydrophobic (SH) protein has been reported to inhibit signaling through type I and type II interferon (IFN) receptors in vitro in part by preventing STAT1 phosphorylation (A. K. Hastings et al., Virology (Auckl) 494:248-256, 2016, https://doi.org/10.1016/j.virol.2016.04.022). HMPV infection also inhibits IL-6 signaling. However, the mechanisms by which SH inhibits signaling and its involvement in IL-6 signaling inhibition are unknown. Here, we used transfection of SH expression plasmids and SH-deleted virus (ΔSH) to show that SH is the viral factor responsible for the inhibition of IL-6 signaling during HMPV infection. Transfection of SH-expression vectors or infection with wild-type, but not ΔSH virus, blocked IL-6-mediated STAT3 activation. Furthermore, JAK1 protein (but not RNA) was significantly reduced in cells infected with wild-type, but not ΔSH virus. The SH-mediated reduction of JAK1 was partially restored by the addition of proteasome inhibitors, suggesting proteasomal degradation of JAK1. Confocal microscopy indicated that infection relocalized JAK1 to viral replication factories. Co-immunoprecipitation showed that SH interacts with JAK1 and ubiquitin, further linking SH to proteasomal degradation machinery. These data indicate that SH inhibits IL-6 and IFN signaling in infected cells in part by promoting proteasomal degradation of JAK1 and that SH is necessary for IL-6 and IFN signaling inhibition in infection. These findings enhance our understanding of the immune evasion mechanisms of an important respiratory pathogen.IMPORTANCEHuman metapneumovirus (HMPV) is a common cause of severe respiratory illness, especially in children and older adults, in whom it is a leading cause of hospitalization. Prior research suggests that severe HMPV infection is driven by a strong immune response to the virus, especially by inflammatory immune signals like interferons (IFN). HMPV produces a small hydrophobic (SH) protein that is known to block IFN signaling, but the mechanism by which it functions and its ability to inhibit other important immune signals remains unexplored. This paper demonstrates that SH can inhibit another related immune signal, IL-6, and that SH depletes JAKs, which are critical proteins involved in both IL-6 and IFN signaling. A robust understanding of how HMPV and related viruses interfere with immune signals important for disease could pave the way for future treatments aimed at mitigating severe infections.
RESUMEN
A key mediator of T cell impairment during respiratory virus infection is the inhibitory receptor PD-1. PD-1 is induced on T cells following antigen exposure, whereas proinflammatory cytokines upregulate the ligands PD-L1 and PD-L2. Respiratory virus infection leads to upregulation of PD-L1 on airway epithelial cells, dendritic cells, and alveolar macrophages. However, the role of PD-L1 on different cell types in acute respiratory virus infections is not known. We sought to determine the role of PD-L1 on different cell types in CD8+ T cell impairment. We found that PD-L1-/- mice challenged with human metapneumovirus or influenza showed a similar level of CD8+ T cell impairment compared to wild-type (WT) mice. Moreover, virus clearance was delayed in PD-L1-/- mice compared to WT. CD8+ T cells from PD-L1-deficient mice expressed higher levels of inhibitory receptors both at baseline and after respiratory virus infection. The antibody blockade of PD-L2 failed to restore function to the impaired cells. While reciprocal bone marrow chimeras between WT and PD-L1-/- mice did not restore CD8+ T cell function after the respiratory virus challenge, mice that received the PD-L1-/- bone marrow had higher inhibitory receptor expression on CD8+ cells. This discrepancy in the inhibitory receptor expression suggests that cells of the hematopoietic compartment contribute to T cell impairment on CD8+ T cells.IMPORTANCEThe phenomenon of pulmonary CD8+ T cell impairment with diminished antiviral function occurs during acute respiratory virus infection mediated by Programmed Cell Death-1 (PD-1) signaling. Moreover, PD-1 blockade enhances T cell function to hasten viral clearance. The ligand PD-L1 is expressed in many cell types, but which cells drive lung T cell impairment is not known. We used genetic approaches to determine the contribution of PD-L1 on lung T cell impairment. We found that PD-L2 cannot compensate for the loss of PD-L1, and PD-L1-deficient mice exhibit increased expression of other inhibitory receptors. Bone marrow chimeras between PD-L1-deficient and wild-type mice indicated that hematopoietic PD-L1 expression is associated with inhibitory receptor upregulation and impairment.
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Antígeno B7-H1 , Linfocitos T CD8-positivos , Proteína 2 Ligando de Muerte Celular Programada 1 , Animales , Humanos , Ratones , Antígeno B7-H1/metabolismo , Antígeno B7-H1/genética , Antígeno B7-H1/inmunología , Linfocitos T CD8-positivos/inmunología , Células Dendríticas/inmunología , Metapneumovirus/inmunología , Ratones Endogámicos C57BL , Ratones Noqueados , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/virología , Infecciones por Paramyxoviridae/inmunología , Infecciones por Paramyxoviridae/virología , Infecciones por Paramyxoviridae/genética , Proteína 2 Ligando de Muerte Celular Programada 1/genética , Proteína 2 Ligando de Muerte Celular Programada 1/metabolismo , Receptor de Muerte Celular Programada 1/metabolismo , Receptor de Muerte Celular Programada 1/genética , Receptor de Muerte Celular Programada 1/inmunología , Infecciones del Sistema Respiratorio/inmunología , Infecciones del Sistema Respiratorio/virologíaRESUMEN
Ocean warming and acidification driven by anthropogenic carbon emissions pose an existential threat to marine calcifying communities. A similar perturbation to global carbon cycling and ocean chemistry occurred â¼56 Ma during the Paleocene-Eocene thermal maximum (PETM), but microfossil records of the marine biotic response are distorted by sediment mixing. Here, we use the carbon isotope excursion marking the PETM to distinguish planktic foraminifer shells calcified during the PETM from those calcified prior to the event and then isotopically filter anachronous specimens from the PETM microfossil assemblages. We find that nearly one-half of foraminifer shells in a deep-sea PETM record from the central Pacific (Ocean Drilling Program Site 865) are reworked contaminants. Contrary to previous interpretations, corrected assemblages reveal a transient but significant decrease in tropical planktic foraminifer diversity at this open-ocean site during the PETM. The decrease in local diversity was caused by extirpation of shallow- and deep-dwelling taxa as they underwent extratropical migrations in response to heat stress, with one prominent lineage showing signs of impaired calcification possibly due to ocean acidification. An absence of subbotinids in the corrected assemblages suggests that ocean deoxygenation may have rendered thermocline depths uninhabitable for some deeper-dwelling taxa. Latitudinal range shifts provided a rapid-response survival mechanism for tropical planktic foraminifers during the PETM, but the rapidity of ocean warming and acidification projected for the coming centuries will likely strain the adaptability of these resilient calcifiers.
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Ácidos/química , Calentamiento Global , Plancton , Planeta Tierra , Fósiles , IsótoposRESUMEN
Respiratory viral infections remain a leading cause of morbidity and mortality. Using a murine model of human metapneumovirus, we identified recruitment of a C1q-expressing inflammatory monocyte population concomitant with viral clearance by adaptive immune cells. Genetic ablation of C1q led to reduced CD8+ T-cell function. Production of C1q by a myeloid lineage was necessary to enhance CD8+ T-cell function. Activated and dividing CD8+ T cells expressed a C1q receptor, gC1qR. Perturbation of gC1qR signaling led to altered CD8+ T-cell IFN-γ production, metabolic capacity, and cell proliferation. Autopsy specimens from fatal respiratory viral infections in children exhibited diffuse production of C1q by an interstitial population. Humans with severe coronavirus disease (COVID-19) infection also exhibited upregulation of gC1qR on activated and rapidly dividing CD8+ T cells. Collectively, these studies implicate C1q production from monocytes as a critical regulator of CD8+ T-cell function following respiratory viral infection.
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Linfocitos T CD8-positivos , Monocitos , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Animales , Monocitos/inmunología , Monocitos/metabolismo , Humanos , Ratones , Metapneumovirus/inmunología , COVID-19/inmunología , COVID-19/virología , COVID-19/patología , COVID-19/metabolismo , Complemento C1q/metabolismo , Complemento C1q/genética , SARS-CoV-2/inmunología , Ratones Endogámicos C57BL , Interferón gamma/metabolismo , Activación de Linfocitos/inmunología , Infecciones del Sistema Respiratorio/inmunología , Infecciones del Sistema Respiratorio/virología , Infecciones del Sistema Respiratorio/patología , Infecciones del Sistema Respiratorio/metabolismo , Infecciones por Paramyxoviridae/inmunología , Infecciones por Paramyxoviridae/virología , Infecciones por Paramyxoviridae/metabolismoRESUMEN
BACKGROUND: Respiratory syncytial virus (RSV) is a leading cause of acute respiratory illnesses in children. RSV can be broadly categorized into 2 major subtypes: A and B. RSV subtypes have been known to cocirculate with variability in different regions of the world. Clinical associations with viral subtype have been studied among children with conflicting findings such that no conclusive relationships between RSV subtype and severity have been established. METHODS: During 2016-2020, children aged <5 years were enrolled in prospective surveillance in the emergency department or inpatient settings at 7 US pediatric medical centers. Surveillance data collection included parent/guardian interviews, chart reviews, and collection of midturbinate nasal plus/minus throat swabs for RSV (RSV-A, RSV-B, and untyped) using reverse transcription polymerase chain reaction. RESULTS: Among 6398 RSV-positive children aged <5 years, 3424 (54%) had subtype RSV-A infections, 2602 (41%) had subtype RSV-B infections, and 272 (5%) were not typed, inconclusive, or mixed infections. In both adjusted and unadjusted analyses, RSV-A-positive children were more likely to be hospitalized, as well as when restricted to <1 year. By season, RSV-A and RSV-B cocirculated in varying levels, with 1 subtype dominating proportionally. CONCLUSIONS: Findings indicate that RSV-A and RSV-B may only be marginally clinically distinguishable, but both subtypes are associated with medically attended illness in children aged <5 years. Furthermore, circulation of RSV subtypes varies substantially each year, seasonally and geographically. With introduction of new RSV prevention products, this highlights the importance of continued monitoring of RSV-A and RSV-B subtypes.
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Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Estaciones del Año , Humanos , Infecciones por Virus Sincitial Respiratorio/epidemiología , Infecciones por Virus Sincitial Respiratorio/virología , Infecciones por Virus Sincitial Respiratorio/prevención & control , Lactante , Preescolar , Estados Unidos/epidemiología , Virus Sincitial Respiratorio Humano/genética , Virus Sincitial Respiratorio Humano/clasificación , Virus Sincitial Respiratorio Humano/aislamiento & purificación , Masculino , Femenino , Estudios Prospectivos , Hospitalización/estadística & datos numéricos , Recién Nacido , Vacunas contra Virus Sincitial Respiratorio/administración & dosificaciónRESUMEN
Underprioritization of mental health is a global problem and threatens the decades-long progress of the US President's Emergency Plan for AIDS Relief (PEPFAR) program. In recent years, mental health has become globally recognized as a part of universal healthcare, making this an opportune moment for the global community to integrate mental health services into routine programming. PEPFAR is well positioned to lead by example. We conceptualized 5 key strategies that might help serve as a framework to support mental health programming as part of PEPFAR's current 5-year strategic plan. PEPFAR and the global community have an opportunity to identify mental health service gaps and interweave global mental health priorities with actions to end the HIV and TB epidemics by 2030.
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Epidemias , Infecciones por VIH , Servicios de Salud Mental , Tuberculosis , Humanos , Salud Mental , Tuberculosis/epidemiología , Tuberculosis/prevención & control , Infecciones por VIH/epidemiologíaRESUMEN
The influence of transporters on the pharmacokinetics of drugs is being increasingly recognized, and drug-drug interactions (DDIs) via modulation of transporters could lead to clinical adverse events. Organic anion-transporting polypeptide 1B (OATP1B) is a liver-specific uptake transporter in humans that can transport a broad range of substrates, including statins. It is a challenge to predict OATP1B-mediated DDIs using preclinical animal models because of species differences in substrate specificity and abundance levels of transporters. PXB-mice are chimeric mice with humanized livers that are highly repopulated with human hepatocytes and have been widely used for drug metabolism and pharmacokinetics studies in drug discovery. In the present study, we measured the exposure increases [blood AUC (area under the blood/plasma concentration-time curve) and Cmax] of 10 OATP1B substrates in PXB-mice upon coadministration with rifampin, a potent OATP1B specific inhibitor. These data in PXB-mice were then compared with the observed DDIs between OATP1B substrates and single-dose rifampin in humans. Our findings suggest that the DDIs between OATP1B substrates and rifampin in PXB-mouse are comparable with the observed DDIs in the clinic. Since most OATP1B substrates are metabolized by cytochromes P450 (CYPs) and/or are substrates of P-glycoprotein (P-gp), we further validated the utility of PXB-mice to predict complex DDIs involving inhibition of OATP1B, CYPs, and P-gp using cyclosporin A (CsA) and gemfibrozil as perpetrators. Overall, the data support that the chimeric mice with humanized livers could be a useful tool for the prediction of hepatic OATP1B-mediated DDIs in humans. SIGNIFICANCE STATEMENT: The ability of PXB-mouse with humanized liver to predict organic anion-transporting polypeptide 1B (OATP1B)-mediated drug-drug interactions (DDIs) in humans was evaluated. The blood exposure increases of 10 OATP1B substrates with rifampin, an OATP1B inhibitor, in PXB-mice have a good correlation with those observed in humans. More importantly, PXB-mice can predict complex DDIs, including inhibition of OATP1B, cytochromes P450 (CYPs), and P-glycoprotein (P-gp) in humans. PXB-mice are a promising useful tool to assess OATP1B-mediated clinical DDIs.
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Interacciones Farmacológicas , Hepatocitos , Transportador 1 de Anión Orgánico Específico del Hígado , Hígado , Rifampin , Animales , Humanos , Ratones , Transportador 1 de Anión Orgánico Específico del Hígado/metabolismo , Transportador 1 de Anión Orgánico Específico del Hígado/antagonistas & inhibidores , Hígado/metabolismo , Hígado/efectos de los fármacos , Rifampin/farmacología , Hepatocitos/metabolismo , Hepatocitos/efectos de los fármacos , Masculino , Quimera , Área Bajo la CurvaRESUMEN
Respiratory syncytial virus (RSV) is the leading cause of hospitalization among infants in the United States. In August 2023, CDC's Advisory Committee on Immunization Practices recommended nirsevimab, a long-acting monoclonal antibody, for infants aged <8 months to protect against RSV-associated lower respiratory tract infection during their first RSV season and for children aged 8-19 months at increased risk for severe RSV disease. In phase 3 clinical trials, nirsevimab efficacy against RSV-associated lower respiratory tract infection with hospitalization was 81% (95% CI = 62%-90%) through 150 days after receipt; post-introduction effectiveness has not been assessed in the United States. In this analysis, the New Vaccine Surveillance Network evaluated nirsevimab effectiveness against RSV-associated hospitalization among infants in their first RSV season during October 1, 2023-February 29, 2024. Among 699 infants hospitalized with acute respiratory illness, 59 (8%) received nirsevimab ≥7 days before symptom onset. Nirsevimab effectiveness was 90% (95% CI = 75%-96%) against RSV-associated hospitalization with a median time from receipt to symptom onset of 45 days (IQR = 19-76 days). The number of infants who received nirsevimab was too low to stratify by duration from receipt; however, nirsevimab effectiveness is expected to decrease with increasing time after receipt because of antibody decay. Although nirsevimab uptake and the interval from receipt of nirsevimab were limited in this analysis, this early estimate supports the current nirsevimab recommendation for the prevention of severe RSV disease in infants. Infants should be protected by maternal RSV vaccination or infant receipt of nirsevimab.
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Anticuerpos Monoclonales Humanizados , Infecciones por Virus Sincitial Respiratorio , Vacunas contra Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Infecciones del Sistema Respiratorio , Lactante , Niño , Humanos , Estados Unidos/epidemiología , Estaciones del Año , Infecciones por Virus Sincitial Respiratorio/epidemiología , Infecciones por Virus Sincitial Respiratorio/prevención & control , Hospitalización , Infecciones del Sistema Respiratorio/epidemiologíaRESUMEN
BACKGROUND: Malaria remains a major public health problem, especially among children in sub-Saharan Africa. Knowledge of malaria parasite prevalence informs targeted interventions and helps to monitor the effectiveness of those interventions. This study aimed to determine prevalence and factors associated with malaria in children aged 6 months to 10 years in the Greater Accra Region of Ghana. METHODS: A community-based cross-sectional study was conducted among 8,741 children aged 6-59 months and 8,292 children aged 5-10 years in all 29 districts of the Greater Accra Region of Ghana in October 2020. Systematic random sampling was used to select communities, households and study participants. A structured questionnaire was used to collect data from caregivers. Rapid diagnostic test kits were used to determine the presence of malaria parasites in blood samples collected by fingerprick. Factors associated with malaria RDT-positivity were determined using multivariate logistic regression analysis. RESULTS: Of 8727 children aged 6-59 months and 8279 aged 5-10 years from whom blood samples were obtained, positive results were obtained for 289 (3.3%; 95% CI 3.0-3.7) and 406 (4.9%; 95% CI 4.5-5.4) respectively. Malaria parasite prevalence in the districts ranged from 0.9 to 10.7% and 1.4-15.0% in children aged 6-59 months and 5-10 years respectively. Factors associated with increased odds of malaria included higher age (AOR = 1.43; 95% CI 1.14-1.71), and living in households without nets on the windows (AOR 1.64; 95% CI 1.10-2.45). On the other hand, living in households located in urban communities was associated with a lower risk of malaria (AOR 0.56; 95% CI 0.40-0.78). CONCLUSION: The average prevalence of malaria in the Greater Accra Region is low compared with other regions. However, there are potential hotspots that need to be targeted with appropriate interventions to accelerate the drive towards malaria elimination.
Asunto(s)
Malaria , Ghana/epidemiología , Humanos , Estudios Transversales , Preescolar , Prevalencia , Lactante , Malaria/epidemiología , Masculino , Femenino , Niño , Factores de RiesgoRESUMEN
OBJECTIVES: Behavioral and psychological symptoms of dementia (BPSD) are common and impart a significant burden to patients, caregivers, and the health system. However, there are few pharmacological options for treating BPSD. We conducted a systematic review of clinical trials examining the efficacy of anticonvulsants in BPSD. METHODS: We searched five electronic databases through January 2023, for randomized controlled trials and systematic reviews evaluating the efficacy of non-benzodiazepine anticonvulsants for the treatment of BPSD. We used the Cochrane risk of bias tool to ascertain the risk of bias in included trials. Because statistical pooling of results using meta-analysis was not feasible, we synthesized findings using the Cochrane Synthesis Without Meta-analysis reporting guidelines. RESULTS: We identified 12 studies, including randomized controlled trials (RCTs) and 1 systematic review. Five RCTs evaluating valproic acid were synthesized by a recent Cochrane review which concluded that this drug is likely ineffective for BPSD. We extracted data from 6 trials involving 248 individuals comparing non-benzodiazepine anticonvulsants to either placebo or risperidone. Four trials (n = 97 participants) evaluated carbamazepine, only one of which demonstrated an improvement in the Brief Psychiatric Rating Scale measuring agitation, hostility, psychosis, and withdrawal/depression (effect size: 1.13; 95% confidence interval [CI]: 0.54-1.73) relative to placebo. Adverse effects were more common in patients receiving carbamazepine (20/27; 74%) relative to placebo (5/24; 21%). There is low quality evidence that oxcarbazepine is likely ineffective and that topiramate may be comparable to risperidone. CONCLUSION: Anticonvulsants are unlikely to be effective in BPSD, although the quality of existing evidence is low.
Asunto(s)
Anticonvulsivantes , Demencia , Humanos , Demencia/tratamiento farmacológico , Anticonvulsivantes/uso terapéutico , Síntomas Conductuales/tratamiento farmacológico , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
AIMS: Dried blood volumetric absorptive microsamples (VAMS) may facilitate home-based sampling to enhance therapeutic drug monitoring after transplantation. This study aimed to clinically validate a liquid chromatography-tandem mass spectrometry assay using 2 VAMS devices with different sampling locations (Tasso-M20 for the upper arm and Mitra for the finger). Patient preferences were also evaluated. METHODS: Clinical validation was performed for tacrolimus and mycophenolic acid by comparison of paired VAMS and venipuncture samples using Passing-Bablok regression and Bland-Altman analysis. Conversion of mycophenolic acid VAMS to serum concentrations was evaluated using haematocrit-dependent formulas and fixed correction factors defined a priori. Patients' perspectives, including useability, acceptability and feasibility, were also investigated using established questionnaires. RESULTS: Paired samples (n = 50) were collected from 25 kidney transplant recipients. Differences for tacrolimus whole-blood concentration were within ±20% for 86 and 88% of samples from the upper arm and fingerstick, respectively. Using correction factors of 1.3 for the upper-arm and 1.47 for finger-prick samples, 84 and 76% of the paired samples, respectively, were within ±20% for mycophenolic acid serum concentration. Patient experience surveys demonstrated limited pain and acceptable useability of the upper-arm device. CONCLUSIONS: Tacrolimus and mycophenolic acid can be measured using 2 common VAMS devices with similar analytical performance. Patients are supportive of home-based monitoring with a preference for the Tasso-M20 device.
RESUMEN
JRK is a DNA-binding protein of the pogo superfamily of transposons, which includes the well-known centromere binding protein B (CENP-B). Jrk null mice exhibit epilepsy, and growth and reproductive disorders, consistent with its relatively high expression in the brain and reproductive tissues. Human JRK DNA variants and gene expression levels are implicated in cancers and neuropsychiatric disorders. JRK protein modulates ß-catenin-TCF activity but little is known of its cellular functions. Based on its homology to CENP-B, we determined whether JRK binds centromeric or other satellite DNAs. We show that human JRK binds satellite III DNA, which is abundant at the chromosome 9q12 juxtacentromeric region and on Yq12, both sites of nuclear stress body assembly. Human JRK-GFP overexpressed in HeLa cells strongly localises to 9q12. Using an anti-JRK antiserum we show that endogenous JRK co-localises with a subset of centromeres in non-stressed cells, and with heat shock factor 1 following heat shock. Knockdown of JRK in HeLa cells proportionately reduces heat shock protein gene expression in heat-shocked cells. A role for JRK in regulating the heat shock response is consistent with the mouse Jrk null phenotype and suggests that human JRK may act as a modifier of diseases with a cellular stress component.