RESUMEN
B.1.351 is the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant most resistant to antibody neutralization. We demonstrate how the dose and number of immunizations influence protection. Nonhuman primates received two doses of 30 or 100 µg of Moderna's mRNA-1273 vaccine, a single immunization of 30 µg, or no vaccine. Two doses of 100 µg of mRNA-1273 induced 50% inhibitory reciprocal serum dilution neutralizing antibody titers against live SARS-CoV-2 p.Asp614Gly and B.1.351 of 3,300 and 240, respectively. Higher neutralizing responses against B.1.617.2 were also observed after two doses compared to a single dose. After challenge with B.1.351, there was ~4- to 5-log10 reduction of viral subgenomic RNA and low to undetectable replication in bronchoalveolar lavages in the two-dose vaccine groups, with a 1-log10 reduction in nasal swabs in the 100-µg group. These data establish that a two-dose regimen of mRNA-1273 will be critical for providing upper and lower airway protection against major variants of concern.
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Vacunas contra la COVID-19/inmunología , COVID-19/inmunología , Primates/inmunología , SARS-CoV-2/inmunología , Vacuna nCoV-2019 mRNA-1273 , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , COVID-19/virología , Línea Celular , Chlorocebus aethiops , Femenino , Humanos , Macaca mulatta , Masculino , Mesocricetus , Primates/virología , ARN Viral/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Vacunación/métodos , Células Vero , Carga Viral/métodosRESUMEN
Vaccine-associated enhanced respiratory disease (VAERD) was previously observed in some preclinical models of severe acute respiratory syndrome (SARS) and MERS coronavirus vaccines. We used the SARS coronavirus 2 (SARS-CoV-2) mouse-adapted, passage 10, lethal challenge virus (MA10) mouse model of acute lung injury to evaluate the immune response and potential for immunopathology in animals vaccinated with research-grade mRNA-1273. Whole-inactivated virus or heat-denatured spike protein subunit vaccines with alum designed to elicit low-potency antibodies and Th2-skewed CD4+ T cells resulted in reduced viral titers and weight loss post challenge but more severe pathological changes in the lung compared to saline-immunized animals. In contrast, a protective dose of mRNA-1273 induced favorable humoral and cellular immune responses that protected from viral replication in the upper and lower respiratory tract upon challenge. A subprotective dose of mRNA-1273 reduced viral replication and limited histopathological manifestations compared to animals given saline. Overall, our findings demonstrate an immunological signature associated with antiviral protection without disease enhancement following vaccination with mRNA-1273.
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Vacunas contra la COVID-19/inmunología , COVID-19/inmunología , COVID-19/prevención & control , Interacciones Huésped-Patógeno/inmunología , SARS-CoV-2/inmunología , Vacunas Sintéticas/inmunología , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Biopsia , Vacunas contra la COVID-19/administración & dosificación , Modelos Animales de Enfermedad , Humanos , Inmunoglobulina G , Inmunohistoquímica , Ratones , Evaluación de Resultado en la Atención de Salud , ARN Mensajero , Glicoproteína de la Espiga del Coronavirus/inmunología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Vacunas Sintéticas/administración & dosificación , Vacunas de ARNmRESUMEN
Microglia is considered the central nervous system (CNS) resident macrophages that establish an innate immune response against pathogens and toxins. However, the recent studies have shown that microglial gene and protein expression follows a circadian pattern; several immune activation markers and clock genes are expressed rhythmically without the need for an immune stimulus. Furthermore, microglia responds to an immune challenge with different magnitudes depending on the time of the day. This review examines the circadian control of microglia function and the possible physiological implications. For example, we discuss that synaptic prune is performed in the cortex at a certain moment of the day. We also consider the implications of daily microglial function for maintaining biological rhythms like general activity, body temperature, and food intake. We conclude that the developmental stage, brain region, and pathological state are not the only factors to consider for the evaluation of microglial functions; instead, emerging evidence indicates that circadian time as an essential aspect for a better understanding of the role of microglia in CNS physiology.
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Microglía , Fenómenos Fisiológicos , Microglía/fisiología , Macrófagos , Sistema Nervioso Central , Encéfalo , Inmunidad InnataRESUMEN
BACKGROUND: Vaccines to prevent coronavirus disease 2019 (Covid-19) are urgently needed. The effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines on viral replication in both upper and lower airways is important to evaluate in nonhuman primates. METHODS: Nonhuman primates received 10 or 100 µg of mRNA-1273, a vaccine encoding the prefusion-stabilized spike protein of SARS-CoV-2, or no vaccine. Antibody and T-cell responses were assessed before upper- and lower-airway challenge with SARS-CoV-2. Active viral replication and viral genomes in bronchoalveolar-lavage (BAL) fluid and nasal swab specimens were assessed by polymerase chain reaction, and histopathological analysis and viral quantification were performed on lung-tissue specimens. RESULTS: The mRNA-1273 vaccine candidate induced antibody levels exceeding those in human convalescent-phase serum, with live-virus reciprocal 50% inhibitory dilution (ID50) geometric mean titers of 501 in the 10-µg dose group and 3481 in the 100-µg dose group. Vaccination induced type 1 helper T-cell (Th1)-biased CD4 T-cell responses and low or undetectable Th2 or CD8 T-cell responses. Viral replication was not detectable in BAL fluid by day 2 after challenge in seven of eight animals in both vaccinated groups. No viral replication was detectable in the nose of any of the eight animals in the 100-µg dose group by day 2 after challenge, and limited inflammation or detectable viral genome or antigen was noted in lungs of animals in either vaccine group. CONCLUSIONS: Vaccination of nonhuman primates with mRNA-1273 induced robust SARS-CoV-2 neutralizing activity, rapid protection in the upper and lower airways, and no pathologic changes in the lung. (Funded by the National Institutes of Health and others.).
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Betacoronavirus/inmunología , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/prevención & control , Pandemias/prevención & control , Neumonía Viral/inmunología , Neumonía Viral/prevención & control , Vacunas Virales/inmunología , Vacuna nCoV-2019 mRNA-1273 , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Betacoronavirus/fisiología , Antígenos CD4 , COVID-19 , Vacunas contra la COVID-19 , Infecciones por Coronavirus/patología , Infecciones por Coronavirus/terapia , Modelos Animales de Enfermedad , Relación Dosis-Respuesta Inmunológica , Inmunización Pasiva , Pulmón/patología , Pulmón/virología , Macaca mulatta , Neumonía Viral/patología , Neumonía Viral/terapia , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Linfocitos T/inmunología , Carga Viral , Vacunas Virales/administración & dosificación , Replicación Viral , Sueroterapia para COVID-19RESUMEN
Microvessels in the central nervous system (CNS) have one of the highest populations of pericytes, indicating their crucial role in maintaining homeostasis. Pericytes are heterogeneous cells located around brain microvessels; they present three different morphologies along the CNS vascular tree: ensheathing, mesh, and thin-strand pericytes. At the arteriole-capillary transition ensheathing pericytes are found, while mesh and thin-strand pericytes are located at capillary beds. Brain pericytes are essential for the establishment and maintenance of the blood-brain barrier, which restricts the passage of soluble and potentially toxic molecules from the circulatory system to the brain parenchyma. Pericytes play a key role in regulating local inflammation at the CNS. Pericytes can respond differentially, depending on the degree of inflammation, by secreting a set of neurotrophic factors to promote cell survival and regeneration, or by potentiating inflammation through the release of inflammatory mediators (e.g., cytokines and chemokines), and the overexpression of cell adhesion molecules. Under inflammatory conditions, pericytes may regulate immune cell trafficking to the CNS and play a role in perpetuating local inflammation. In this review, we describe pericyte responses during acute and chronic neuroinflammation.
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Enfermedades Neuroinflamatorias , Pericitos , Adulto , Humanos , Encéfalo/irrigación sanguínea , Barrera Hematoencefálica , Sistema Nervioso CentralRESUMEN
PURPOSE: To understand clinician and clinical staff perspectives on the implementation of routine Adverse Childhood Experience (ACE) screening in pediatric primary care. METHODS: We conducted a qualitative evaluation in 5 clinics in Los Angeles County, California, using 2 rounds of focus group discussions: during an early phase of the initiative, and 7 months later. In the first round, we conducted 14 focus group discussions with 67 participants. In the second round, we conducted 12 focus group discussions with 58 participants. Participants comprised clinic staff involved in ACE screening, including frontline staff that administer the screening, medical clinicians that use screening to counsel patients and make referrals, and psychosocial support staff who may receive referrals. RESULTS: Themes were grouped into 3 categories: (1) screening acceptability and perceived utility, (2) implementation and quality improvement, and (3) effects of screening on patients and clinicians. Regarding screening acceptability and perceived utility, clinicians generally considered ACE screening to be acceptable and useful. In terms of implementation and quality improvement, significant barriers included: insufficient time for screening and response, insufficient training, and lack of clarity about referral networks and resources that could be offered to patients. Lastly, regarding effects of screening, clinicians expressed that ACE screening helped elicit important patient information and build trust with patients. Further, no adverse events were reported from screening. CONCLUSIONS: Clinic staff felt ACE screening was feasible, acceptable, and beneficial within pediatric care settings to improve trauma-informed care and that ACE screening could be strengthened by addressing time constraints and limited referral resources.
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Experiencias Adversas de la Infancia , Humanos , Niño , Los Angeles , Instituciones de Atención Ambulatoria , Grupos Focales , Derivación y ConsultaRESUMEN
BACKGROUND: While breastfeeding rates have increased in the United States in recent years, racial and ethnic disparities persist. Telelactation may help reduce disparities by increasing access to lactation consultants, but there is limited research on acceptability among minoritized individuals. OBJECTIVE: We aimed to explore experiences with telelactation among Black parents and identify strategies to make services more culturally appropriate. METHODS: We selected 20 Black parents who were given access to telelactation services from an ongoing National Institutes of Health-funded randomized controlled trial (the Tele-MILC trial) to participate in semistructured interviews. Interviews addressed birth experiences, use and opinions about telelactation, comparison of telelactation to in-person lactation support, and recommendations to improve telelactation services. The thematic analysis was informed by a previously reported theoretical framework of acceptability and RAND Corporation's equity-centered model. RESULTS: Users appreciated the convenience of telelactation and reported that lactation consultants were knowledgeable and helpful. Participants wanted more options to engage with lactation consultants outside of video visits (eg, SMS text messaging and asynchronous resources). Users who had a lactation consultant of color mentioned that racial concordance improved the experience; however, few felt that racial concordance was needed for high-quality telelactation support. CONCLUSIONS: While Black parents in our sample found telelactation services to be acceptable, telelactation could not, in isolation, address the myriad barriers to long-duration breastfeeding. Several changes could be made to telelactation services to increase their use by minoritized populations.
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Negro o Afroamericano , Lactancia Materna , Aceptación de la Atención de Salud , Telemedicina , Femenino , Humanos , Consultores , Atención Posnatal , Investigación Cualitativa , Estados Unidos , Negro o Afroamericano/psicología , Ensayos Clínicos Controlados Aleatorios como Asunto , Aceptación de la Atención de Salud/etnologíaRESUMEN
Background: We conducted a national, cross-sectional survey among new parents to explore use and acceptability of telelactation. Methods: Recruitment occurred between October 2021 and January 2022 on Ovia's parenting mobile phone application. Poststratification survey weights were used, and logistic and linear regression models estimated associations between demographics and telelactation use. Results: Among 1,617 respondents, 33.8% had at least one telelactation visit. Odds of any telelactation visit(s) were greater for parents who gave birth in 2021 versus 2019 (odds ratio [OR]: 1.69, 95% confidence interval [CI]: 1.26-2.25), insured by Medicaid (OR: 1.43, 95% CI: 1.02-2.02), and younger parents (OR: 2.07, 95% CI: 1.32-3.34). In total, 56.0% agreed that they would be comfortable breastfeeding over video to get help, and 27.6% agreed that lactation support over video is as good as in-person support. Conclusions: Telelactation is increasingly common and acceptable to many parents.
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Lactancia Materna , Telemedicina , Femenino , Humanos , Estudios Transversales , Padres , ActitudRESUMEN
Respiratory syncytial virus (RSV) is a major human pathogen that infects the majority of children by two years of age. The RSV fusion (F) protein is a primary target of human antibodies, and it has several antigenic regions capable of inducing neutralizing antibodies. Antigenic site IV is preserved in both the pre-fusion and post-fusion conformations of RSV F. Antibodies to antigenic site IV have been described that bind and neutralize both RSV and human metapneumovirus (hMPV). To explore the diversity of binding modes at antigenic site IV, we generated a panel of four new human monoclonal antibodies (mAbs) and competition-binding suggested the mAbs bind at antigenic site IV. Mutagenesis experiments revealed that binding and neutralization of two mAbs (3M3 and 6F18) depended on arginine (R) residue R429. We discovered two R429-independent mAbs (17E10 and 2N6) at this site that neutralized an RSV R429A mutant strain, and one of these mAbs (17E10) neutralized both RSV and hMPV. To determine the mechanism of cross-reactivity, we performed competition-binding, recombinant protein mutagenesis, peptide binding, and electron microscopy experiments. It was determined that the human cross-reactive mAb 17E10 binds to RSV F with a binding pose similar to 101F, which may be indicative of cross-reactivity with hMPV F. The data presented provide new concepts in RSV immune recognition and vaccine design, as we describe the novel idea that binding pose may influence mAb cross-reactivity between RSV and hMPV. Characterization of the site IV epitope bound by human antibodies may inform the design of a pan-Pneumovirus vaccine.
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Anticuerpos Monoclonales/metabolismo , Anticuerpos Neutralizantes/metabolismo , Anticuerpos Antivirales/metabolismo , Epítopos/metabolismo , Virus Sincitial Respiratorio Humano/metabolismo , Proteínas Virales de Fusión/metabolismo , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Anticuerpos Monoclonales/química , Anticuerpos Neutralizantes/química , Anticuerpos Antivirales/química , Especificidad de Anticuerpos , Sitios de Unión de Anticuerpos , Unión Competitiva , Reacciones Cruzadas , Mapeo Epitopo , Humanos , Cinética , Metapneumovirus/inmunología , Metapneumovirus/metabolismo , Microscopía Electrónica , Mutación , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Virus Sincitial Respiratorio Humano/inmunología , Proteínas Virales de Fusión/antagonistas & inhibidores , Proteínas Virales de Fusión/genéticaRESUMEN
Sleep loss in the rat increases blood-brain barrier permeability to circulating molecules by disrupting interendothelial tight junctions. Despite the description of the ultrastructure of cerebral microvessels and the evidence of an apparent pericyte detachment from capillary wall in sleep restricted rats the effect of sleep loss on pericytes is unknown. Here we characterized the interactions between pericytes and brain endothelial cells after sleep loss using male Wistar rats. Animals were sleep-restricted 20 h daily with 4 h sleep recovery for 10 days. At the end of the sleep restriction, brain microvessels (MVs) were isolated from cerebral cortex and hippocampus and processed for Western blot and immunocytochemistry to evaluate markers of pericyte-endothelial cell interaction (connexin 43, PDGFR-ß), tight junction proteins, and proinflammatory mediator proteins (MMP9, A2A adenosine receptor, CD73, NFκB). Sleep restriction reduced PDGFR-ß and connexin 43 expression in MVs; in addition, scanning electron microscopy micrographs showed that pericytes were detached from capillary walls, but did not undergo apoptosis (as depicted by a reduced active caspase-3 expression). Sleep restriction also decreased tight junction protein expression in MVs and increased BBB permeability to low- and high-molecular weight tracers in in vivo permeability assays. Those alterations seemed to depend on a low-grade inflammatory status as reflected by the increased expression of phosphorylated NFκB and A2A adenosine receptor in brain endothelial cells from the sleep-restricted rats. Our data show that pericyte-brain endothelial cell interaction is altered by sleep restriction; this evidence is essential to understand the role of sleep in regulating blood-brain barrier function.
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Barrera Hematoencefálica , Pericitos , Animales , Encéfalo , Comunicación Celular , Células Endoteliales , Masculino , Ratas , Ratas Wistar , Sueño , Uniones EstrechasRESUMEN
Sleep loss increases blood-brain barrier permeability. As the blood-brain barrier and the blood-tissue barriers in the reproductive tract (blood-testis and blood-epididymis barriers) share common characteristics, we hypothesized that sleep restriction may also modify their barrier function. Previous reports showed that sleep loss decreased sperm viability and progressive fast mobility, which may be a consequence of altered blood-testis and blood-epididymis barrier. Therefore, we quantified changes in blood-testis and blood-epididymis barrier after sleep loss and related them to male fertility. Adult male Wistar rats were sleep restricted using the multiple-platform technique in a protocol of 20 hr daily sleep deprivation plus 4 hr of sleep recovery in the home-cage. At the 10th day, barrier permeability assays were performed with Na-fluorescein, 10 kDa Cascade blue-dextrans and Evans blue, and the expression of tight junction proteins, actin and androgen receptor was quantified. At the 10th day of sleep restriction and after sleep recovery days 1-7, males were placed with sexually receptive females, sexual behaviour was tested, and the percentage of pregnancies was calculated. Sleep restriction increased the barrier permeability to low- and high-molecular-weight tracers, and decreased the expression of tight junction proteins, actin and androgen receptor. Concomitantly, sleep restriction reduced the percentage of ejaculating males and the number of pregnancies. Sleep recovery for 2-3 days progressively re-established fertility, as indicated by a higher percentage of ejaculating males and impregnated females. In conclusion, chronic sleep loss alters fertility concomitantly with the disruption of the blood-tissue barriers at the reproductive tract, the mechanism involves androgen signalling.
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Barrera Hematoencefálica/fisiopatología , Epidídimo/fisiopatología , Fertilidad/fisiología , Microscopía Confocal/métodos , Trastornos del Inicio y del Mantenimiento del Sueño/complicaciones , Animales , Enfermedad Crónica , Humanos , Masculino , Ratas , Ratas Wistar , Privación de Sueño/fisiopatología , Testículo/fisiopatologíaRESUMEN
BACKGROUND & AIMS: Human noroviruses are responsible for approximately 200,000 deaths worldwide each year. In 2012, the GII.4 Sydney strain emerged and became the major circulating norovirus strain associated with human disease. Our understanding of the human norovirus-specific antibody response is limited because few human monoclonal antibodies (mAbs) to noroviruses have been described, and there are no functional assays to measure virus neutralization. We studied the antibody-mediated response to the genogroup (G) II.4 strain by isolating mAbs to GII.4 from infected patients and developing virus neutralization assays. METHODS: We used a robust human hybridoma technique to isolate mAbs from patients previously infected with norovirus and identified mAbs that blocked virus binding to cell receptors, using virus-like particles to test blockade ability. We tested the ability of select mAbs to neutralize live human noroviruses using stem cell-derived human enteroids. RESULTS: We isolated a panel of 25 IgG or IgA human mAbs that recognized norovirus GII.4 Sydney 2012 and determined their potential to block virus binding to cell receptors. In competition binding studies, most antibodies recognized 3 major antigenic sites on the GII.4 Sydney 2012 protruding (P) domain. CONCLUSIONS: We isolated and characterized human mAbs that neutralize live human norovirus GII.4 Sydney 2012-the predominant strain responsible for recent outbreaks. Analyses of these antibodies identified neutralizing epitopes; further studies will provide insight into the human immune response to this deadly virus.
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Anticuerpos Monoclonales/inmunología , Anticuerpos Antivirales/inmunología , Infecciones por Caliciviridae/virología , Norovirus/inmunología , Anticuerpos Monoclonales/aislamiento & purificación , Anticuerpos Antivirales/aislamiento & purificación , Humanos , Acoplamiento ViralRESUMEN
Human noroviruses (HuNoVs) cause sporadic and epidemic gastroenteritis worldwide. They are classified into two major genogroups (GI and GII), with each genogroup further divided into multiple genotypes. Susceptibility to these viruses is influenced by genetically determined histo-blood group antigen (HBGA) expression. HBGAs function as cell attachment factors by binding to a surface-exposed region in the protruding (P) domain of the capsid protein. Sequence variations in this region that result in differential HBGA binding patterns and antigenicity are suggested to form a basis for strain diversification. Recent studies show that serum antibodies that block HBGA binding correlate with protection against illness. Although genogroup-dependent variation in HBGA binding specificity is structurally well characterized, an understanding of how antibodies block HBGA binding and how genotypic variations affect such blockade is lacking. Our crystallographic studies of the GI.1 P domain in complex with the Fab fragment of a human IgA monoclonal antibody (IgA 5I2) with HBGA blocking activity show that the antibody recognizes a conformational epitope formed by two surface-exposed loop clusters in the P domain. The antibody engulfs the HBGA binding site but does not affect its structural integrity. An unusual feature of the antigen recognition by IgA 5I2 is the predominant involvement of the CDR light chain 1 in contrast to the commonly observed CDR heavy chain 3, providing a unique perspective into antibody diversity in antigen recognition. Identification of the antigenic site in the P domain shows how genotypic variations might allow escape from antibody neutralization and exemplifies the interplay between antigenicity and HBGA specificity in HuNoV evolution.
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Anticuerpos Bloqueadores/farmacología , Antígenos de Grupos Sanguíneos/inmunología , Inmunoglobulina A/metabolismo , Pruebas de Neutralización , Norovirus/inmunología , Secuencia de Aminoácidos , Antígenos/química , Cristalografía por Rayos X , Epítopos/química , Genotipo , Humanos , Fragmentos Fab de Inmunoglobulinas/metabolismo , Modelos Moleculares , Norovirus/efectos de los fármacos , Norovirus/genética , Dominios Proteicos , Proteínas Virales/química , Proteínas Virales/metabolismoRESUMEN
Palivizumab was the first antiviral monoclonal antibody (mAb) approved for therapeutic use in humans, and remains a prophylactic treatment for infants at risk for severe disease because of respiratory syncytial virus (RSV). Palivizumab is an engineered humanized version of a murine mAb targeting antigenic site II of the RSV fusion (F) protein, a key target in vaccine development. There are limited reported naturally occurring human mAbs to site II; therefore, the structural basis for human antibody recognition of this major antigenic site is poorly understood. Here, we describe a nonneutralizing class of site II-specific mAbs that competed for binding with palivizumab to postfusion RSV F protein. We also describe two classes of site II-specific neutralizing mAbs, one of which escaped competition with nonneutralizing mAbs. An X-ray crystal structure of the neutralizing mAb 14N4 in complex with F protein showed that the binding angle at which human neutralizing mAbs interact with antigenic site II determines whether or not nonneutralizing antibodies compete with their binding. Fine-mapping studies determined that nonneutralizing mAbs that interfere with binding of neutralizing mAbs recognize site II with a pose that facilitates binding to an epitope containing F surface residues on a neighboring protomer. Neutralizing antibodies, like motavizumab and a new mAb designated 3J20 that escape interference by the inhibiting mAbs, avoid such contact by binding at an angle that is shifted away from the nonneutralizing site. Furthermore, binding to rationally and computationally designed site II helix-loop-helix epitope-scaffold vaccines distinguished neutralizing from nonneutralizing site II antibodies.
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Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Virus Sincitial Respiratorio Humano/inmunología , Proteínas Virales de Fusión/inmunología , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales Humanizados/inmunología , Anticuerpos Neutralizantes/química , Antivirales/farmacología , Línea Celular , Cristalografía por Rayos X , Mapeo Epitopo , Epítopos/inmunología , Humanos , Ratones , Mutagénesis , Palivizumab/farmacología , Vacunas contra Virus Sincitial Respiratorio/química , Vacunas contra Virus Sincitial Respiratorio/inmunología , Virus Sincitial Respiratorio Humano/efectos de los fármacosRESUMEN
Noroviruses (NoV) are the most common cause of non-bacterial acute gastroenteritis and cause local outbreaks of illness, especially in confined situations. Despite being identified four decades ago, the correlates of protection against norovirus gastroenteritis are still being elucidated. Recent studies have shown an association of protection with NoV-specific serum histo-blood group antigen-blocking antibody and with serum IgA in patients vaccinated with NoV VLPs. Here, we describe the isolation and characterization of human monoclonal IgG and IgA antibodies against a GI.I NoV, Norwalk virus (NV). A higher proportion of the IgA antibodies blocked NV VLP binding to glycans than did IgG antibodies. We generated isotype-switched variants of IgG and IgA antibodies to study the effects of the constant domain on blocking and binding activities. The IgA form of antibodies appears to be more potent than the IgG form in blocking norovirus binding to histo-blood group antigens. These studies suggest a unique role for IgA antibodies in protection from NoV infections by blocking attachment to cell receptors.
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Anticuerpos Monoclonales/inmunología , Linfocitos B/inmunología , Antígenos de Grupos Sanguíneos/inmunología , Infecciones por Caliciviridae/inmunología , Western Blotting , Línea Celular , Ensayo de Inmunoadsorción Enzimática , Gastroenteritis/inmunología , Humanos , Hibridomas , Inmunoglobulina A/inmunología , Inmunoglobulina G/inmunología , Virus Norwalk/inmunología , Reacción en Cadena de la PolimerasaRESUMEN
Rab11a is a key component of the apical recycling endosome that aids in the trafficking of proteins to the luminal surface in polarized epithelial cells. Utilizing conditional Rab11a-knockout specific to intestinal epithelial cells, and human colonic epithelial CaCo2-BBE cells with stable Rab11a knockdown, we examined the molecular and pathological impact of Rab11a deficiency on the establishment of apical cell polarity and microvillus morphogenesis. We demonstrate that loss of Rab11a induced alterations in enterocyte polarity, shortened microvillar length and affected the formation of microvilli along the lateral membranes. Rab11a deficiency in enterocytes altered the apical localization of syntaxin 3. These data affirm the role of Rab11a in apical membrane trafficking and the maintenance of apical microvilli in enterocytes.
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Enterocitos/ultraestructura , Microvellosidades/metabolismo , Proteínas Qa-SNARE/metabolismo , Proteínas de Unión al GTP rab/metabolismo , Animales , Células CACO-2 , Polaridad Celular , Endosomas/metabolismo , Células HEK293 , Humanos , Ratones , Ratones Noqueados , Transporte de ProteínasRESUMEN
Phagocytosis is critical to tissue homeostasis, as highlighted by phagocytosis defect of retinal pigment epithelial (RPE) cells with debris accumulation, photoreceptor degeneration and blindness. Phagocytosis ligands are the key to delineating molecular mechanisms and functional roles of phagocytes, but are traditionally identified in individual cases with technical challenges. We recently developed open reading frame phage display (OPD) for phagocytosis-based functional cloning (PFC) to identify unknown ligands. One of the identified ligands was Ly-1 antibody reactive clone (Lyar) with functions poorly defined. Herein, we characterized Lyar as a new ligand to stimulate RPE phagocytosis. In contrast to its reported nucleolar expression, immunohistochemistry showed that Lyar was highly expressed in photoreceptor outer segments (POSs) of the retina. Cytoplasmic Lyar was released from apoptotic cells, and selectively bound to shed POSs and apoptotic cells, but not healthy cells. POS vesicles engulfed through Lyar-dependent pathway were targeted to phagosomes and colocalized with phagosome marker Rab7. These results suggest that Lyar is a genuine RPE phagocytosis ligand, which in turn supports the validity of OPD/PFC as the only available approach for unbiased identification of phagocytosis ligands with broad applicability to various phagocytes.
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Proteínas de Unión al ADN/genética , Proteínas Nucleares/genética , Retina/metabolismo , Segmento Externo de las Células Fotorreceptoras Retinianas/metabolismo , Proteínas de Unión al GTP rab/metabolismo , Animales , Apoptosis/genética , Proteínas de Unión al ADN/metabolismo , Ligandos , Ratones , Proteínas Nucleares/metabolismo , Fagocitos/metabolismo , Fagocitosis/genética , Retina/crecimiento & desarrollo , Epitelio Pigmentado de la Retina/metabolismo , Pigmentos Retinianos/genética , Pigmentos Retinianos/metabolismo , Proteínas de Unión al GTP rab/genética , Proteínas de Unión a GTP rab7RESUMEN
Messenger RNA encoded signals that are involved in programmed -1 ribosomal frameshifting (-1 PRF) are typically two-stemmed hairpin (H)-type pseudoknots (pks). We previously described an unusual three-stemmed pseudoknot from the severe acute respiratory syndrome (SARS) coronavirus (CoV) that stimulated -1 PRF. The conserved existence of a third stem-loop suggested an important hitherto unknown function. Here we present new information describing structure and function of the third stem of the SARS pseudoknot. We uncovered RNA dimerization through a palindromic sequence embedded in the SARS-CoV Stem 3. Further in vitro analysis revealed that SARS-CoV RNA dimers assemble through 'kissing' loop-loop interactions. We also show that loop-loop kissing complex formation becomes more efficient at physiological temperature and in the presence of magnesium. When the palindromic sequence was mutated, in vitro RNA dimerization was abolished, and frameshifting was reduced from 15 to 5.7%. Furthermore, the inability to dimerize caused by the silent codon change in Stem 3 of SARS-CoV changed the viral growth kinetics and affected the levels of genomic and subgenomic RNA in infected cells. These results suggest that the homodimeric RNA complex formed by the SARS pseudoknot occurs in the cellular environment and that loop-loop kissing interactions involving Stem 3 modulate -1 PRF and play a role in subgenomic and full-length RNA synthesis.
Asunto(s)
Sistema de Lectura Ribosómico , ARN Viral/química , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/genética , Secuencia de Bases , Codón , Secuencia Conservada , Dimerización , Secuencias Invertidas Repetidas , Cinética , Magnesio/química , Viabilidad Microbiana , Datos de Secuencia Molecular , Mutación , Resonancia Magnética Nuclear Biomolecular , Conformación de Ácido Nucleico , TemperaturaRESUMEN
BACKGROUND: The field of maternal health has advanced significantly over the past decades. However, the United States continues to have poor outcomes in comparison with other industrialized nations. With emerging evidence on the promise of doula care, states are including doula care under their Medicaid programs. METHODS: We conducted a scoping review across four academic databases and gray literature published between January 1, 2012, and March 10, 2022, to describe the landscape of literature on U.S. doula programs and their outcomes in order to inform state policy makers considering laws or programs related to doula care. FINDINGS: Of 740 records identified, 100 met inclusion criteria. Outcomes fell into four areas: birthing people's outcomes, infant outcomes, systems of care and implementation, and cross-cutting issues. Data on outcomes related to doula care in the literature were predominantly clinical, even though doulas are not clinical providers. Although some studies have found associations between doula care and improved clinical outcomes for birthing people and infants, the evidence is limited due to small sample sizes, study methodology, or conflicting conclusions. Doula outcomes are underexplored in the literature, with mainly qualitative data describing low levels of diversity and equity within the doula workforce and ineffective payment models. When cost-effectiveness estimates have been calculated, they largely rely on savings realized from averted cesarean births, preterm births, and neonatal intensive care unit admissions. CONCLUSIONS: As state Medicaid programs expand to include doula care, policymakers should be aware of the limitations in the evidence as they plan for successful implementation, such as the narrow focus on certain clinical outcomes to quantify cost savings and conflicting conclusions on the impact of doula care. An important consideration is the impact of the reimbursement rate on the adoption of doula care, which is why it is important to engage doulas in compensation determinations, as well as the development of improved metrics to untangle the components that contribute to maternal health outcomes in the United States.
Asunto(s)
Doulas , Política de Salud , Medicaid , Humanos , Estados Unidos , Embarazo , Femenino , Parto Obstétrico , Servicios de Salud Materna , Salud Materna , Resultado del Embarazo , Gobierno Estatal , Recién NacidoRESUMEN
Brucellosis is an infection widely distributed around the world, and in some countries it is considered a public health problem. Brucellosis causes insidious symptoms that make it difficult to diagnose. Infection can also trigger chronic pain and neuropsychiatric complications. Antibiotics are not always effective to eradicate infection, contributing to chronicity. We aimed to investigate the effects of antibiotic treatment on proinflammatory cytokines, neurotransmitters, corticosterone, and behavior in a murine model of infecrion of B. abortus strain 2308. Four study groups were created: (a) control; (b) antibiotic control; (c) infected with B. abortus 2308; and (d) infected and treated with rifampicin and doxycycline. We determined B. abortus 2308 colony-forming units (CFUs), the count of dendritic cells, and macrophages in the spleen; serum levels of cytokines and corticosterone; levels of serotonin, dopamine, epinephrine, and norepinephrine in the brain; and equilibrium, physical strength, anxiety, and hopelessness tests. The infected and treated mice group was compared with the control and infected mice to assess whether treatment is sufficient to recover neuroimmunoendocrine parameters. Our results showed that despite the treatment of brucellosis with rifampicin and doxycycline, antibiotic-treated mice showed a persistence of B. abortus 2308 CFUs, an increased count in macrophage number, and higher circulating levels of corticosterone. Furthermore, the levels of IL-12, IL-6, and TNF-α remained higher. We found a decrease in muscular strength and equilibrium concomitant to changes in neurotransmitters in the hippocampus, cerebellum, and frontal cortex. Our data suggest that the remaining bacterial load after antibiotic administration favors inflammatory, neurochemical, and behavioral alterations, partly explaining the widespread and paradoxical symptomatology experienced by patients with chronic brucellosis.