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1.
Nat Immunol ; 22(12): 1490-1502, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34616036

RESUMEN

Despite extensive studies into severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the effect of maternal infection on the neonate is unclear. To investigate this, we characterized the immunology of neonates born to mothers with confirmed SARS-CoV-2 infection during pregnancy. Here we show that maternal SARS-CoV-2 infection affects the neonatal immune system. Despite similar proportions of B cells, CD4+ T cells and CD8+ T cells, increased percentages of natural killer cells, Vδ2+ γδ T cells and regulatory T cells were detected in neonates born to mothers with recent or ongoing infection compared with those born to recovered or uninfected mothers. Increased plasma cytokine levels were also evident in neonates and mothers within the recent or ongoing infection group. Cytokine functionality was enhanced in neonates born to SARS-CoV-2-exposed mothers, compared to those born to uninfected mothers. In most neonates, this immune imprinting was nonspecific, suggesting vertical transmission of SARS-CoV-2 is limited, a finding supported by a lack of SARS-CoV-2-specific IgM in neonates despite maternal IgG transfer.


Asunto(s)
COVID-19/inmunología , Enfermedades del Recién Nacido/inmunología , Transmisión Vertical de Enfermedad Infecciosa , Complicaciones Infecciosas del Embarazo/inmunología , SARS-CoV-2/inmunología , Adulto , Anticuerpos Antivirales/inmunología , COVID-19/diagnóstico , COVID-19/virología , Citocinas/sangre , Citocinas/inmunología , Citocinas/metabolismo , Femenino , Humanos , Inmunidad Innata/inmunología , Inmunoglobulina G/inmunología , Recién Nacido , Enfermedades del Recién Nacido/diagnóstico , Enfermedades del Recién Nacido/virología , Células Asesinas Naturales/inmunología , Embarazo , Complicaciones Infecciosas del Embarazo/virología , Receptores de Antígenos de Linfocitos T gamma-delta/inmunología , Receptores de Antígenos de Linfocitos T gamma-delta/metabolismo , SARS-CoV-2/fisiología , Linfocitos T/inmunología , Linfocitos T/metabolismo , Linfocitos T Reguladores/inmunología
2.
Immunity ; 54(6): 1276-1289.e6, 2021 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-33836142

RESUMEN

Interaction of the SARS-CoV-2 Spike receptor binding domain (RBD) with the receptor ACE2 on host cells is essential for viral entry. RBD is the dominant target for neutralizing antibodies, and several neutralizing epitopes on RBD have been molecularly characterized. Analysis of circulating SARS-CoV-2 variants has revealed mutations arising in the RBD, N-terminal domain (NTD) and S2 subunits of Spike. To understand how these mutations affect Spike antigenicity, we isolated and characterized >100 monoclonal antibodies targeting epitopes on RBD, NTD, and S2 from SARS-CoV-2-infected individuals. Approximately 45% showed neutralizing activity, of which ∼20% were NTD specific. NTD-specific antibodies formed two distinct groups: the first was highly potent against infectious virus, whereas the second was less potent and displayed glycan-dependant neutralization activity. Mutations present in B.1.1.7 Spike frequently conferred neutralization resistance to NTD-specific antibodies. This work demonstrates that neutralizing antibodies targeting subdominant epitopes should be considered when investigating antigenic drift in emerging variants.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Anticuerpos Antivirales/inmunología , COVID-19/inmunología , COVID-19/virología , Epítopos/inmunología , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Enzima Convertidora de Angiotensina 2/química , Enzima Convertidora de Angiotensina 2/metabolismo , Anticuerpos Monoclonales/química , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/química , COVID-19/diagnóstico , Reacciones Cruzadas/inmunología , Epítopos/química , Epítopos/genética , Humanos , Modelos Moleculares , Mutación , Pruebas de Neutralización , Unión Proteica/inmunología , Conformación Proteica , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Relación Estructura-Actividad
3.
J Virol ; 98(10): e0063824, 2024 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-39240113

RESUMEN

Nipah virus (NiV) is a highly pathogenic paramyxovirus capable of causing severe respiratory and neurologic disease in humans. Currently, there are no licensed vaccines or therapeutics against NiV, underscoring the urgent need for the development of countermeasures. The NiV surface-displayed glycoproteins, NiV-G and NiV-F, mediate host cell attachment and fusion, respectively, and are heavily targeted by host antibodies. Here, we describe a vaccination-derived neutralizing monoclonal antibody, mAb92, that targets NiV-F. Structural characterization of the Fab region bound to NiV-F (NiV-F-Fab92) by cryo-electron microscopy analysis reveals an epitope in the DIII domain at the membrane distal apex of NiV-F, an established site of vulnerability on the NiV surface. Further, prophylactic treatment of hamsters with mAb92 offered complete protection from NiV disease, demonstrating beneficial activity of mAb92 in vivo. This work provides support for targeting NiV-F in the development of vaccines and therapeutics against NiV.IMPORTANCENipah virus (NiV) is a highly lethal henipavirus (HNV) that causes severe respiratory and neurologic disease in humans. Currently, there are no licensed vaccines or therapeutics against NiV, highlighting a need to develop countermeasures. The NiV surface displays the receptor binding protein (NiV-G, or RBP) and the fusion protein (NiV-F), which allow the virus to attach and enter cells. These proteins can be targeted by vaccines and antibodies to prevent disease. This work describes a neutralizing antibody (mAb92) that targets NiV-F. Structural characterization by cryo-electron microscopy analysis reveals where the antibody binds to NiV-F to neutralize the virus. This study also shows that prophylactic treatment of hamsters with mAb92 completely protected against developing NiV disease. This work shows how targeting NiV-F can be useful to preventing NiV disease, supporting future studies in the development of vaccines and therapeutics.


Asunto(s)
Anticuerpos Monoclonales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Infecciones por Henipavirus , Virus Nipah , Proteínas Virales de Fusión , Virus Nipah/inmunología , Animales , Infecciones por Henipavirus/prevención & control , Infecciones por Henipavirus/inmunología , Anticuerpos Monoclonales/inmunología , Proteínas Virales de Fusión/inmunología , Proteínas Virales de Fusión/química , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Cricetinae , Humanos , Microscopía por Crioelectrón , Epítopos/inmunología , Mesocricetus
4.
Proc Natl Acad Sci U S A ; 119(34): e2201541119, 2022 08 23.
Artículo en Inglés | MEDLINE | ID: mdl-35943978

RESUMEN

Whereas pathogen-specific T and B cells are a primary focus of interest during infectious disease, we have used COVID-19 to ask whether their emergence comes at a cost of broader B cell and T cell repertoire disruption. We applied a genomic DNA-based approach to concurrently study the immunoglobulin-heavy (IGH) and T cell receptor (TCR) ß and δ chain loci of 95 individuals. Our approach detected anticipated repertoire focusing for the IGH repertoire, including expansions of clusters of related sequences temporally aligned with SARS-CoV-2-specific seroconversion, and enrichment of some shared SARS-CoV-2-associated sequences. No significant age-related or disease severity-related deficiencies were noted for the IGH repertoire. By contrast, whereas focusing occurred at the TCRß and TCRδ loci, including some TCRß sequence-sharing, disruptive repertoire narrowing was almost entirely limited to many patients aged older than 50 y. By temporarily reducing T cell diversity and by risking expansions of nonbeneficial T cells, these traits may constitute an age-related risk factor for COVID-19, including a vulnerability to new variants for which T cells may provide key protection.


Asunto(s)
Inmunidad Adaptativa , COVID-19 , Cadenas Pesadas de Inmunoglobulina , Receptores de Antígenos de Linfocitos T alfa-beta , Receptores de Antígenos de Linfocitos T , SARS-CoV-2 , Inmunidad Adaptativa/genética , Anciano , Linfocitos B/inmunología , COVID-19/genética , COVID-19/inmunología , Sitios Genéticos , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T alfa-beta/genética , SARS-CoV-2/inmunología , Seroconversión , Linfocitos T/inmunología
5.
PLoS Pathog ; 18(10): e1010882, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36191037

RESUMEN

COVID-19 vaccines are playing a vital role in controlling the COVID-19 pandemic. As SARS-CoV-2 variants encoding mutations in the surface glycoprotein, Spike, continue to emerge, there is increased need to identify immunogens and vaccination regimens that provide the broadest and most durable immune responses. We compared the magnitude and breadth of the neutralizing antibody response, as well as levels of Spike-reactive memory B cells, in individuals receiving a second dose of BNT162b2 at a short (3-4 week) or extended interval (8-12 weeks) and following a third vaccination approximately 6-8 months later. We show that whilst an extended interval between the first two vaccinations can greatly increase the breadth of the immune response and generate a higher proportion of Spike reactive memory B cells, a third vaccination leads to similar levels between the two groups. Furthermore, we show that the third vaccine dose enhances neutralization activity against omicron lineage members BA.1, BA.2 and BA.4/BA.5 and this is further increased following breakthrough infection during the UK omicron wave. These findings are relevant for vaccination strategies in populations where COVID-19 vaccine coverage remains low.


Asunto(s)
COVID-19 , Vacunas Virales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Vacuna BNT162 , COVID-19/prevención & control , Vacunas contra la COVID-19 , Humanos , Glicoproteínas de Membrana/genética , Pandemias , SARS-CoV-2/genética , Vacunación
6.
EMBO Rep ; 23(10): e54322, 2022 10 06.
Artículo en Inglés | MEDLINE | ID: mdl-35999696

RESUMEN

The emergence of SARS-CoV-2 variants has exacerbated the COVID-19 global health crisis. Thus far, all variants carry mutations in the spike glycoprotein, which is a critical determinant of viral transmission being responsible for attachment, receptor engagement and membrane fusion, and an important target of immunity. Variants frequently bear truncations of flexible loops in the N-terminal domain (NTD) of spike; the functional importance of these modifications has remained poorly characterised. We demonstrate that NTD deletions are important for efficient entry by the Alpha and Omicron variants and that this correlates with spike stability. Phylogenetic analysis reveals extensive NTD loop length polymorphisms across the sarbecoviruses, setting an evolutionary precedent for loop remodelling. Guided by these analyses, we demonstrate that variations in NTD loop length, alone, are sufficient to modulate virus entry. We propose that variations in NTD loop length act to fine-tune spike; this may provide a mechanism for SARS-CoV-2 to navigate a complex selection landscape encompassing optimisation of essential functionality, immune-driven antigenic variation and ongoing adaptation to a new host.


Asunto(s)
COVID-19 , SARS-CoV-2 , COVID-19/genética , Humanos , Filogenia , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/genética
7.
PLoS Pathog ; 17(11): e1009820, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34807954

RESUMEN

Interferons play a critical role in regulating host immune responses to SARS-CoV-2, but the interferon (IFN)-stimulated gene (ISG) effectors that inhibit SARS-CoV-2 are not well characterized. The IFN-inducible short isoform of human nuclear receptor coactivator 7 (NCOA7) inhibits endocytic virus entry, interacts with the vacuolar ATPase, and promotes endo-lysosomal vesicle acidification and lysosomal protease activity. Here, we used ectopic expression and gene knockout to demonstrate that NCOA7 inhibits infection by SARS-CoV-2 as well as by lentivirus particles pseudotyped with SARS-CoV-2 Spike in lung epithelial cells. Infection with the highly pathogenic, SARS-CoV-1 and MERS-CoV, or seasonal, HCoV-229E and HCoV-NL63, coronavirus Spike-pseudotyped viruses was also inhibited by NCOA7. Importantly, either overexpression of TMPRSS2, which promotes plasma membrane fusion versus endosomal fusion of SARS-CoV-2, or removal of Spike's polybasic furin cleavage site rendered SARS-CoV-2 less sensitive to NCOA7 restriction. Collectively, our data indicate that furin cleavage sensitizes SARS-CoV-2 Spike to the antiviral consequences of endosomal acidification by NCOA7, and suggest that the acquisition of furin cleavage may have favoured the co-option of cell surface TMPRSS proteases as a strategy to evade the suppressive effects of IFN-induced endo-lysosomal dysregulation on virus infection.


Asunto(s)
COVID-19/virología , Furina/metabolismo , Coactivadores de Receptor Nuclear/metabolismo , SARS-CoV-2/fisiología , Serina Endopeptidasas/metabolismo , Línea Celular , Endosomas/metabolismo , Furina/genética , Expresión Génica , Humanos , Evasión Inmune , Interferones/metabolismo , Lisosomas/enzimología , Coactivadores de Receptor Nuclear/genética , Isoformas de Proteínas , Proteolisis , Serina Endopeptidasas/genética , Glicoproteína de la Espiga del Coronavirus/metabolismo , Pseudotipado Viral , Internalización del Virus
8.
Immunity ; 40(5): 657-68, 2014 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-24768347

RESUMEN

Broadly neutralizing HIV antibodies are much sought after (a) to guide vaccine design, both as templates and as indicators of the authenticity of vaccine candidates, (b) to assist in structural studies, and (c) to serve as potential therapeutics. However, the number of targets on the viral envelope spike for such antibodies has been limited. Here, we describe a set of human monoclonal antibodies that define what is, to the best of our knowledge, a previously undefined target on HIV Env. The antibodies recognize a glycan-dependent epitope on the prefusion conformation of gp41 and unambiguously distinguish cleaved from uncleaved Env trimers, an important property given increasing evidence that cleavage is required for vaccine candidates that seek to mimic the functional HIV envelope spike. The availability of this set of antibodies expands the number of vaccine targets on HIV and provides reagents to characterize the native envelope spike.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Anti-VIH/inmunología , Proteína gp41 de Envoltorio del VIH/inmunología , Línea Celular , Epítopos/inmunología , Células HEK293 , Proteína gp120 de Envoltorio del VIH/inmunología , Proteína gp41 de Envoltorio del VIH/metabolismo , Infecciones por VIH/inmunología , Infecciones por VIH/prevención & control , VIH-1/inmunología , Humanos , Datos de Secuencia Molecular , Polisacáridos/inmunología
9.
BJOG ; 130(9): 1135-1144, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37113111

RESUMEN

OBJECTIVE: To determine severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence in pregnancy in an inner-city setting and assess associations with demographic factors and vaccination timing. DESIGN: Repeated cross-sectional surveillance study. SETTING: London maternity centre. SAMPLE: A total of 906 pregnant women attending nuchal scans, July 2020-January 2022. METHODS: Blood samples were tested for IgG antibodies against SARS-CoV-2 nucleocapsid (N) and spike (S) proteins. Self-reported vaccination status and coronavirus disease 2019 (COVID-19) infection were recorded. Multivariable regression models determined demographic factors associated with seroprevalence and antibody titres. MAIN OUTCOME MEASURES: Immunoglobulin G N- and S-protein antibody titres. RESULTS: Of the 960 women, 196 (20.4%) were SARS-CoV-2 seropositive from previous infection. Of these, 70 (35.7%) self-reported previous infection. Among unvaccinated women, women of black ethnic backgrounds were most likely to be SARS-CoV-2 seropositive (versus white adjusted risk ratio [aRR] 1.88, 95% CI 1.35-2.61, p < 0.001). Women from black and mixed ethnic backgrounds were least likely to have a history of vaccination with seropositivity to S-protein (versus white aRR 0.58, 95% CI 0.40-0.84, p = 0.004; aRR 0.56, 95% CI 0.34-0.92, p = 0.021, respectively). Double vaccinated, previously infected women had higher IgG S-protein antibody titres than unvaccinated, previously infected women (mean difference 4.76 fold-change, 95% CI 2.65-6.86, p < 0.001). Vaccination timing before versus during pregnancy did not affect IgG S-antibody titres (mean difference -0.28 fold-change, 95% CI -2.61 to 2.04, p = 0.785). CONCLUSIONS: This cross-sectional study demonstrates high rates of asymptomatic SARS-CoV-2 infection with women of black ethnic backgrounds having higher infection risk and lower vaccine uptake. SARS-CoV-2 antibody titres were highest among double-vaccinated, infected women.


Asunto(s)
COVID-19 , SARS-CoV-2 , Embarazo , Femenino , Humanos , Estudios Transversales , Prevalencia , Estudios Seroepidemiológicos , COVID-19/epidemiología , COVID-19/prevención & control , Anticuerpos Antivirales , Inmunoglobulina G
10.
Mol Ther ; 30(12): 3639-3657, 2022 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-35949171

RESUMEN

Adenovirus vector vaccines have been widely and successfully deployed in response to coronavirus disease 2019 (COVID-19). However, despite inducing potent T cell immunity, improvement of vaccine-specific antibody responses upon homologous boosting is modest compared with other technologies. Here, we describe a system enabling modular decoration of adenovirus capsid surfaces with antigens and demonstrate potent induction of humoral immunity against these displayed antigens. Ligand attachment via a covalent bond was achieved using a protein superglue, DogTag/DogCatcher (similar to SpyTag/SpyCatcher), in a rapid and spontaneous reaction requiring only co-incubation of ligand and vector components. DogTag was inserted into surface-exposed loops in the adenovirus hexon protein to allow attachment of DogCatcher-fused ligands on virus particles. Efficient coverage of the capsid surface was achieved using various ligands, with vector infectivity retained in each case. Capsid decoration shielded particles from vector neutralizing antibodies. In prime-boost regimens, adenovirus vectors decorated with the receptor-binding domain of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) spike induced >10-fold higher SARS-CoV-2 neutralization titers compared with an undecorated vector encoding spike. Importantly, decorated vectors achieved equivalent or superior T cell immunogenicity against encoded antigens compared with undecorated vectors. We propose capsid decoration using protein superglues as a novel strategy to improve efficacy and boostability of adenovirus-based vaccines and therapeutics.


Asunto(s)
Vacunas contra el Adenovirus , COVID-19 , Humanos , SARS-CoV-2 , Inmunidad Humoral , Ligandos , COVID-19/prevención & control
11.
Int J Obes (Lond) ; 46(8): 1478-1486, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35589964

RESUMEN

BACKGROUND: COVID-19 severity varies widely. Although some demographic and cardio-metabolic factors, including age and obesity, are associated with increasing risk of severe illness, the underlying mechanism(s) are uncertain. SUBJECTS/METHODS: In a meta-analysis of three independent studies of 1471 participants in total, we investigated phenotypic and genetic factors associated with subcutaneous adipose tissue expression of Angiotensin I Converting Enzyme 2 (ACE2), measured by RNA-Seq, which acts as a receptor for SARS-CoV-2 cellular entry. RESULTS: Lower adipose tissue ACE2 expression was associated with multiple adverse cardio-metabolic health indices, including type 2 diabetes (T2D) (P = 9.14 × 10-6), obesity status (P = 4.81 × 10-5), higher serum fasting insulin (P = 5.32 × 10-4), BMI (P = 3.94 × 10-4), and lower serum HDL levels (P = 1.92 × 10-7). ACE2 expression was also associated with estimated proportions of cell types in adipose tissue: lower expression was associated with a lower proportion of microvascular endothelial cells (P = 4.25 × 10-4) and higher proportion of macrophages (P = 2.74 × 10-5). Despite an estimated heritability of 32%, we did not identify any proximal or distal expression quantitative trait loci (eQTLs) associated with adipose tissue ACE2 expression. CONCLUSIONS: Our results demonstrate that individuals with cardio-metabolic features known to increase risk of severe COVID-19 have lower background ACE2 levels in this highly relevant tissue. Reduced adipose tissue ACE2 expression may contribute to the pathophysiology of cardio-metabolic diseases, as well as the associated increased risk of severe COVID-19.


Asunto(s)
Tejido Adiposo , Enzima Convertidora de Angiotensina 2 , COVID-19 , Tejido Adiposo/metabolismo , Enzima Convertidora de Angiotensina 2/genética , Enzima Convertidora de Angiotensina 2/metabolismo , COVID-19/complicaciones , COVID-19/genética , Factores de Riesgo Cardiometabólico , Diabetes Mellitus Tipo 2/genética , Células Endoteliales/metabolismo , Humanos , Obesidad , SARS-CoV-2
12.
J Virol ; 95(9)2021 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-33563656

RESUMEN

The cellular entry of severe acute respiratory syndrome-associated coronaviruses types 1 and 2 (SARS-CoV-1 and -2) requires sequential protease processing of the viral spike glycoprotein. The presence of a polybasic cleavage site in SARS-CoV-2 spike at the S1/S2 boundary has been suggested to be a factor in the increased transmissibility of SARS-CoV-2 compared to SARS-CoV-1 by facilitating maturation of the spike precursor by furin-like proteases in the producer cells rather than endosomal cathepsins in the target. We investigate the relevance of the polybasic cleavage site in the route of entry of SARS-CoV-2 and the consequences this has for sensitivity to interferons (IFNs) and, more specifically, the IFN-induced transmembrane (IFITM) protein family that inhibit entry of diverse enveloped viruses. We found that SARS-CoV-2 is restricted predominantly by IFITM2, rather than IFITM3, and the degree of this restriction is governed by route of viral entry. Importantly, removal of the cleavage site in the spike protein renders SARS-CoV-2 entry highly pH and cathepsin dependent in late endosomes, where, like SARS-CoV-1 spike, it is more sensitive to IFITM2 restriction. Furthermore, we found that potent inhibition of SARS-CoV-2 replication by type I but not type II IFNs is alleviated by targeted depletion of IFITM2 expression. We propose that the polybasic cleavage site allows SARS-CoV-2 to mediate viral entry in a pH-independent manner, in part to mitigate against IFITM-mediated restriction and promote replication and transmission. This suggests that therapeutic strategies that target furin-mediated cleavage of SARS-CoV-2 spike may reduce viral replication through the activity of type I IFNs.IMPORTANCE The furin cleavage site in the spike protein is a distinguishing feature of SARS-CoV-2 and has been proposed to be a determinant for the higher transmissibility between individuals, compared to SARS-CoV-1. One explanation for this is that it permits more efficient activation of fusion at or near the cell surface rather than requiring processing in the endosome of the target cell. Here, we show that SARS-CoV-2 is inhibited by antiviral membrane protein IFITM2 and that the sensitivity is exacerbated by deletion of the furin cleavage site, which restricts viral entry to low pH compartments. Furthermore, we find that IFITM2 is a significant effector of the antiviral activity of type I interferons against SARS-CoV-2 replication. We suggest that one role of the furin cleavage site is to reduce SARS-CoV-2 sensitivity to innate immune restriction, and thus, it may represent a potential therapeutic target for COVID-19 treatment development.


Asunto(s)
Interferón Tipo I/metabolismo , Proteínas de la Membrana/metabolismo , Proteolisis , SARS-CoV-2/fisiología , Glicoproteína de la Espiga del Coronavirus/metabolismo , Internalización del Virus , Replicación Viral , Células A549 , Humanos , Interferón Tipo I/genética , Proteínas de la Membrana/genética , Glicoproteína de la Espiga del Coronavirus/genética
13.
PLoS Pathog ; 16(9): e1008817, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32970782

RESUMEN

There is a clear requirement for an accurate SARS-CoV-2 antibody test, both as a complement to existing diagnostic capabilities and for determining community seroprevalence. We therefore evaluated the performance of a variety of antibody testing technologies and their potential use as diagnostic tools. Highly specific in-house ELISAs were developed for the detection of anti-spike (S), -receptor binding domain (RBD) and -nucleocapsid (N) antibodies and used for the cross-comparison of ten commercial serological assays-a chemiluminescence-based platform, two ELISAs and seven colloidal gold lateral flow immunoassays (LFIAs)-on an identical panel of 110 SARS-CoV-2-positive samples and 50 pre-pandemic negatives. There was a wide variation in the performance of the different platforms, with specificity ranging from 82% to 100%, and overall sensitivity from 60.9% to 87.3%. However, the head-to-head comparison of multiple sero-diagnostic assays on identical sample sets revealed that performance is highly dependent on the time of sampling, with sensitivities of over 95% seen in several tests when assessing samples from more than 20 days post onset of symptoms. Furthermore, these analyses identified clear outlying samples that were negative in all tests, but were later shown to be from individuals with mildest disease presentation. Rigorous comparison of antibody testing platforms will inform the deployment of point-of-care technologies in healthcare settings and their use in the monitoring of SARS-CoV-2 infections.


Asunto(s)
Anticuerpos Antivirales/análisis , Infecciones por Coronavirus/diagnóstico , Neumonía Viral/diagnóstico , Sistemas de Atención de Punto , Pruebas Serológicas/métodos , Adulto , Anciano , Betacoronavirus , COVID-19 , Prueba de COVID-19 , Técnicas de Laboratorio Clínico , Servicios de Salud Comunitaria , Proteínas de la Nucleocápside de Coronavirus , Ensayo de Inmunoadsorción Enzimática , Femenino , Hospitales , Humanos , Inmunoensayo , Mediciones Luminiscentes , Masculino , Persona de Mediana Edad , Proteínas de la Nucleocápside/inmunología , Pandemias , Fosfoproteínas , SARS-CoV-2 , Sensibilidad y Especificidad , Glicoproteína de la Espiga del Coronavirus/inmunología
14.
J Med Virol ; 94(11): 5217-5224, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35864567

RESUMEN

This study assessed T-cell responses in individuals with and without a positive antibody response to SARS-CoV-2, in symptomatic and asymptomatic individuals during the COVID-19 pandemic. Participants were drawn from the TwinsUK cohort, grouped by (a) presence or absence of COVID-associated symptoms (S+, S-), logged prospectively through the COVID Symptom Study app, and (b) anti-IgG Spike and anti-IgG Nucleocapsid antibodies measured by ELISA (Ab+, Ab-), during the first wave of the UK pandemic. T-cell helper and regulatory responses after stimulation with SARS-CoV-2 peptides were assessed. Thirty-two participants were included in the final analysis. Fourteen of 15 with IgG Spike antibodies had a T-cell response to SARS-CoV-2-specific peptides; none of 17 participants without IgG Spike antibodies had a T-cell response (χ2 : 28.2, p < 0.001). Quantitative T-cell responses correlated strongly with fold-change in IgG Spike antibody titer (ρ = 0.79, p < 0.0001) but not to symptom score (ρ = 0.17, p = 0.35). Humoral and cellular immune responses to SARS-CoV-2 are highly correlated. We found no evidence of cellular immunity suggestive of SARS-CoV2 infection in individuals with a COVID-19-like illness but negative antibodies.


Asunto(s)
Linfocitos B , COVID-19 , Linfocitos T , Anticuerpos Antivirales , COVID-19/diagnóstico , Humanos , Inmunoglobulina G , Pandemias , ARN Viral , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus
15.
Proc Natl Acad Sci U S A ; 116(50): 25057-25067, 2019 12 10.
Artículo en Inglés | MEDLINE | ID: mdl-31767754

RESUMEN

Nipah virus (NiV) is a highly pathogenic paramyxovirus that causes frequent outbreaks of severe neurologic and respiratory disease in humans with high case fatality rates. The 2 glycoproteins displayed on the surface of the virus, NiV-G and NiV-F, mediate host-cell attachment and membrane fusion, respectively, and are targets of the host antibody response. Here, we provide a molecular basis for neutralization of NiV through antibody-mediated targeting of NiV-F. Structural characterization of a neutralizing antibody (nAb) in complex with trimeric prefusion NiV-F reveals an epitope at the membrane-distal domain III (DIII) of the molecule, a region that undergoes substantial refolding during host-cell entry. The epitope of this monoclonal antibody (mAb66) is primarily protein-specific and we observe that glycosylation at the periphery of the interface likely does not inhibit mAb66 binding to NiV-F. Further characterization reveals that a Hendra virus-F-specific nAb (mAb36) and many antibodies in an antihenipavirus-F polyclonal antibody mixture (pAb835) also target this region of the molecule. Integrated with previously reported paramyxovirus F-nAb structures, these data support a model whereby the membrane-distal region of the F protein is targeted by the antibody-mediated immune response across henipaviruses. Notably, our domain-specific sequence analysis reveals no evidence of selective pressure at this region of the molecule, suggestive that functional constraints prevent immune-driven sequence variation. Combined, our data reveal the membrane-distal region of NiV-F as a site of vulnerability on the NiV surface.


Asunto(s)
Anticuerpos Neutralizantes , Virus Hendra , Proteínas Virales de Fusión , Internalización del Virus , Anticuerpos Monoclonales , Anticuerpos Neutralizantes/química , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/metabolismo , Línea Celular Tumoral , Glicosilación , Células HEK293 , Virus Hendra/química , Virus Hendra/inmunología , Virus Hendra/metabolismo , Virus Hendra/fisiología , Humanos , Modelos Moleculares , Unión Proteica , Proteínas Virales de Fusión/química , Proteínas Virales de Fusión/inmunología , Proteínas Virales de Fusión/metabolismo
16.
Lancet Oncol ; 22(6): 765-778, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33930323

RESUMEN

BACKGROUND: The efficacy and safety profiles of vaccines against SARS-CoV-2 in patients with cancer is unknown. We aimed to assess the safety and immunogenicity of the BNT162b2 (Pfizer-BioNTech) vaccine in patients with cancer. METHODS: For this prospective observational study, we recruited patients with cancer and healthy controls (mostly health-care workers) from three London hospitals between Dec 8, 2020, and Feb 18, 2021. Participants who were vaccinated between Dec 8 and Dec 29, 2020, received two 30 µg doses of BNT162b2 administered intramuscularly 21 days apart; patients vaccinated after this date received only one 30 µg dose with a planned follow-up boost at 12 weeks. Blood samples were taken before vaccination and at 3 weeks and 5 weeks after the first vaccination. Where possible, serial nasopharyngeal real-time RT-PCR (rRT-PCR) swab tests were done every 10 days or in cases of symptomatic COVID-19. The coprimary endpoints were seroconversion to SARS-CoV-2 spike (S) protein in patients with cancer following the first vaccination with the BNT162b2 vaccine and the effect of vaccine boosting after 21 days on seroconversion. All participants with available data were included in the safety and immunogenicity analyses. Ongoing follow-up is underway for further blood sampling after the delayed (12-week) vaccine boost. This study is registered with the NHS Health Research Authority and Health and Care Research Wales (REC ID 20/HRA/2031). FINDINGS: 151 patients with cancer (95 patients with solid cancer and 56 patients with haematological cancer) and 54 healthy controls were enrolled. For this interim data analysis of the safety and immunogenicity of vaccinated patients with cancer, samples and data obtained up to March 19, 2021, were analysed. After exclusion of 17 patients who had been exposed to SARS-CoV-2 (detected by either antibody seroconversion or a positive rRT-PCR COVID-19 swab test) from the immunogenicity analysis, the proportion of positive anti-S IgG titres at approximately 21 days following a single vaccine inoculum across the three cohorts were 32 (94%; 95% CI 81-98) of 34 healthy controls; 21 (38%; 26-51) of 56 patients with solid cancer, and eight (18%; 10-32) of 44 patients with haematological cancer. 16 healthy controls, 25 patients with solid cancer, and six patients with haematological cancer received a second dose on day 21. Of the patients with available blood samples 2 weeks following a 21-day vaccine boost, and excluding 17 participants with evidence of previous natural SARS-CoV-2 exposure, 18 (95%; 95% CI 75-99) of 19 patients with solid cancer, 12 (100%; 76-100) of 12 healthy controls, and three (60%; 23-88) of five patients with haematological cancers were seropositive, compared with ten (30%; 17-47) of 33, 18 (86%; 65-95) of 21, and four (11%; 4-25) of 36, respectively, who did not receive a boost. The vaccine was well tolerated; no toxicities were reported in 75 (54%) of 140 patients with cancer following the first dose of BNT162b2, and in 22 (71%) of 31 patients with cancer following the second dose. Similarly, no toxicities were reported in 15 (38%) of 40 healthy controls after the first dose and in five (31%) of 16 after the second dose. Injection-site pain within 7 days following the first dose was the most commonly reported local reaction (23 [35%] of 65 patients with cancer; 12 [48%] of 25 healthy controls). No vaccine-related deaths were reported. INTERPRETATION: In patients with cancer, one dose of the BNT162b2 vaccine yields poor efficacy. Immunogenicity increased significantly in patients with solid cancer within 2 weeks of a vaccine boost at day 21 after the first dose. These data support prioritisation of patients with cancer for an early (day 21) second dose of the BNT162b2 vaccine. FUNDING: King's College London, Cancer Research UK, Wellcome Trust, Rosetrees Trust, and Francis Crick Institute.


Asunto(s)
Vacunas contra la COVID-19/uso terapéutico , COVID-19/inmunología , Neoplasias/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antivirales/sangre , Vacuna BNT162 , COVID-19/sangre , COVID-19/complicaciones , COVID-19/virología , Vacunas contra la COVID-19/inmunología , Relación Dosis-Respuesta Inmunológica , Femenino , Humanos , Inmunogenicidad Vacunal/inmunología , Londres/epidemiología , Masculino , Persona de Mediana Edad , Neoplasias/sangre , Neoplasias/complicaciones , Neoplasias/virología , Estudios Prospectivos , SARS-CoV-2 , Gales
17.
Br J Haematol ; 194(6): 999-1006, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34085278

RESUMEN

Patients receiving targeted cancer treatments such as tyrosine kinase inhibitors (TKIs) have been classified in the clinically extremely vulnerable group to develop severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), including patients with chronic myeloid leukaemia (CML) taking TKIs. In addition, concerns that immunocompromised individuals with solid and haematological malignancies may not mount an adequate immune response to a single dose of SARS-CoV-2 BNT162b2 (Pfizer-BioNTech) vaccine have been raised. In the present study, we evaluated humoral and cellular immune responses after a first injection of BNT162b2 vaccine in 16 patients with CML. Seroconversion and cellular immune response before and after vaccination were assessed. By day 21 after vaccination, anti-Spike immunoglobulin G was detected in 14/16 (87·5%) of the patients with CML and all developed a neutralising antibody response [serum dilution that inhibits 50% infection (ID50 ) >50], including medium (ID50 of 200-500) or high (ID50 of 501-2000) neutralising antibodies titres in nine of the 16 (56·25%) patients. T-cell response was seen in 14/15 (93·3%) evaluable patients, with polyfunctional responses seen in 12/15 (80%) patients (polyfunctional CD4+ response nine of 15, polyfunctional CD8+ T-cell response nine of 15). These data demonstrate the immunogenicity of a single dose of SARS-CoV-2 BNT162b2 vaccine in most patients with CML, with both neutralising antibodies and polyfunctional T-cell responses seen in contrast to patients with solid tumour or lymphoid haematological malignancies.


Asunto(s)
Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Vacunas contra la COVID-19/administración & dosificación , COVID-19 , Neoplasias Hematológicas/inmunología , Inmunidad Celular/efectos de los fármacos , Inmunoglobulina G/inmunología , Leucemia Mielógena Crónica BCR-ABL Positiva/inmunología , SARS-CoV-2/inmunología , Adulto , Anciano , Vacuna BNT162 , COVID-19/inmunología , COVID-19/prevención & control , Vacunas contra la COVID-19/inmunología , Femenino , Neoplasias Hematológicas/tratamiento farmacológico , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Inhibidores de Proteínas Quinasas/administración & dosificación , Glicoproteína de la Espiga del Coronavirus/inmunología
18.
Curr Top Microbiol Immunol ; 428: 129-163, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-30046985

RESUMEN

Glycosylation is an important post-translational modification that is required for structural and stability purposes and functional roles such as signalling, attachment and shielding. Many human pathogens such as bacteria display an array of carbohydrates on their surface that are non-self to the host; others such as viruses highjack the host-cell machinery and present self-carbohydrates sometimes arranged in a non-self more immunogenic manner. In combination with carrier proteins, these glycan structures can be highly immunogenic. During natural infection, glycan-binding antibodies are often elicited that correlate with long-lasting protection. A great amount of research has been invested in carbohydrate vaccine design to elicit such an immune response, which has led to the development of vaccines against the bacterial pathogens Haemophilus influenzae type b, Streptococcus pneumonia and Neisseria meningitidis. Other vaccines, e.g. against HIV-1, are still in development, but promising progress has been made with the isolation of broadly neutralizing glycan-binding antibodies and the engineering of stable trimeric envelope glycoproteins. Carbohydrate vaccines against other pathogens such as viruses (Dengue, Hepatitis C), parasites (Plasmodium) and fungi (Candida) are at different stages of development. This chapter will discuss the challenges in inducing cross-reactive carbohydrate-targeting antibodies and progress towards carbohydrate vaccines.


Asunto(s)
Polisacáridos/inmunología , Vacunas/química , Vacunas/inmunología , Vacunología , Virulencia/inmunología , Vacunas contra el SIDA/química , Vacunas contra el SIDA/inmunología , Anticuerpos/inmunología , Vacunas Bacterianas/química , Vacunas Bacterianas/inmunología , Glicosilación , Humanos
19.
Proc Natl Acad Sci U S A ; 114(27): 7031-7036, 2017 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-28630325

RESUMEN

Transmission of hemorrhagic fever New World arenaviruses from their rodent reservoirs to human populations poses substantial public health and economic dangers. These zoonotic events are enabled by the specific interaction between the New World arenaviral attachment glycoprotein, GP1, and cell surface human transferrin receptor (hTfR1). Here, we present the structural basis for how a mouse-derived neutralizing antibody (nAb), OD01, disrupts this interaction by targeting the receptor-binding surface of the GP1 glycoprotein from Junín virus (JUNV), a hemorrhagic fever arenavirus endemic in central Argentina. Comparison of our structure with that of a previously reported nAb complex (JUNV GP1-GD01) reveals largely overlapping epitopes but highly distinct antibody-binding modes. Despite differences in GP1 recognition, we find that both antibodies present a key tyrosine residue, albeit on different chains, that inserts into a central pocket on JUNV GP1 and effectively mimics the contacts made by the host TfR1. These data provide a molecular-level description of how antibodies derived from different germline origins arrive at equivalent immunological solutions to virus neutralization.


Asunto(s)
Anticuerpos Neutralizantes/inmunología , Fiebre Hemorrágica Americana/inmunología , Pruebas de Neutralización , Anticuerpos Monoclonales/inmunología , Anticuerpos Antivirales/inmunología , Sitios de Unión , Cristalografía por Rayos X , Ensayo de Inmunoadsorción Enzimática , Epítopos/química , Glicoproteínas/química , Células HEK293 , Humanos , Sistema Inmunológico , Virus Junin , Unión Proteica , Proteínas Recombinantes/inmunología , Proteínas del Envoltorio Viral/química
20.
Anal Chem ; 90(12): 7325-7331, 2018 06 19.
Artículo en Inglés | MEDLINE | ID: mdl-29757629

RESUMEN

The development of domain-exchanged antibodies offers a route to high-affinity targeting to clustered multivalent epitopes, such as those associated with viral infections and many cancers. One strategy to generate these antibodies is to introduce mutations into target antibodies to drive domain exchange using the only known naturally occurring domain-exchanged anti-HIV (anti-human immunodeficiency virus) IgG1 antibody, 2G12 , as a template. Here, we show that domain exchange can be sensitively monitored by ion-mobility mass spectrometry and gas-phase collision-induced unfolding. Using native 2G12 and a mutated form that disrupts domain exchange such that it has a canonical IgG1 architecture ( 2G12 I19R ), we show that the two forms can be readily distinguished by their unfolding profiles. Importantly, the same signature of domain exchange is observed for both intact antibody and isolated Fab fragments. The development of a mass spectrometric method to detect antibody domain exchange will enable rapid screening and selection of candidate antibodies engineered to exhibit this and other unusual quaternary antibody architectures.


Asunto(s)
Inmunoglobulina G/química , Espectrometría de Masas/métodos , Anticuerpos Monoclonales , Anticuerpos Neutralizantes , Anticuerpos ampliamente neutralizantes , Anticuerpos Anti-VIH , Humanos , Fragmentos Fab de Inmunoglobulinas , Inmunoglobulina G/genética , Proteínas Mutantes , Ingeniería de Proteínas , Estructura Cuaternaria de Proteína , Desplegamiento Proteico
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