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Most studies of adaptive immunity to SARS-CoV-2 infection focus on peripheral blood, which may not fully reflect immune responses at the site of infection. Using samples from 110 children undergoing tonsillectomy and adenoidectomy during the COVID-19 pandemic, we identified 24 samples with evidence of previous SARS-CoV-2 infection, including neutralizing antibodies in serum and SARS-CoV-2-specific germinal center and memory B cells in the tonsils and adenoids. Single-cell B cell receptor (BCR) sequencing indicated virus-specific BCRs were class-switched and somatically hypermutated, with overlapping clones in the two tissues. Expanded T cell clonotypes were found in tonsils, adenoids and blood post-COVID-19, some with CDR3 sequences identical to previously reported SARS-CoV-2-reactive T cell receptors (TCRs). Pharyngeal tissues from COVID-19-convalescent children showed persistent expansion of germinal center and antiviral lymphocyte populations associated with interferon (IFN)-γ-type responses, particularly in the adenoids, and viral RNA in both tissues. Our results provide evidence for persistent tissue-specific immunity to SARS-CoV-2 in the upper respiratory tract of children after infection.
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COVID-19 , SARS-CoV-2 , Humanos , Niño , Pandemias , Inmunidad Adaptativa , Tonsila Palatina , Anticuerpos AntiviralesRESUMEN
There is limited understanding of the viral antibody fingerprint following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children. Herein, SARS-CoV-2 proteome-wide immunoprofiling of children with mild/moderate or severe coronavirus disease 2019 (COVID-19) versus multisystem inflammatory syndrome in children versus hospitalized control patients revealed differential cytokine responses, IgM/IgG/IgA epitope diversity, antibody binding and avidity. Apart from spike and nucleocapsid, IgG/IgA recognized epitopes in nonstructural protein (NSP) 2, NSP3, NSP12-NSP14 and open reading frame (ORF) 3a-ORF9. Peptides representing epitopes in NSP12, ORF3a and ORF8 demonstrated SARS-CoV-2 serodiagnosis. Antibody-binding kinetics with 24 SARS-CoV-2 proteins revealed antibody parameters that distinguish children with mild/moderate versus severe COVID-19 or multisystem inflammatory syndrome in children. Antibody avidity to prefusion spike correlated with decreased illness severity and served as a clinical disease indicator. The fusion peptide and heptad repeat 2 region induced SARS-CoV-2-neutralizing antibodies in rabbits. Thus, we identified SARS-CoV-2 antibody signatures in children associated with disease severity and delineate promising serodiagnostic and virus neutralization targets. These findings might guide the design of serodiagnostic assays, prognostic algorithms, therapeutics and vaccines in this important but understudied population.
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Prueba Serológica para COVID-19/métodos , COVID-19/complicaciones , COVID-19/inmunología , SARS-CoV-2/inmunología , Síndrome de Respuesta Inflamatoria Sistémica/inmunología , Adolescente , Anticuerpos Neutralizantes/metabolismo , Anticuerpos Antivirales/metabolismo , COVID-19/diagnóstico , Niño , Preescolar , Progresión de la Enfermedad , Epítopos/metabolismo , Femenino , Hospitalización , Humanos , Inmunidad Humoral , Inmunoglobulina A/metabolismo , Inmunoglobulina G/metabolismo , Inmunoglobulina M/metabolismo , Masculino , Pronóstico , Proteoma , Índice de Severidad de la Enfermedad , Síndrome de Respuesta Inflamatoria Sistémica/diagnósticoRESUMEN
Acute viral infections can have durable functional impacts on the immune system long after recovery, but how they affect homeostatic immune states and responses to future perturbations remain poorly understood1-4. Here we use systems immunology approaches, including longitudinal multimodal single-cell analysis (surface proteins, transcriptome and V(D)J sequences) to comparatively assess baseline immune statuses and responses to influenza vaccination in 33 healthy individuals after recovery from mild, non-hospitalized COVID-19 (mean, 151 days after diagnosis) and 40 age- and sex-matched control individuals who had never had COVID-19. At the baseline and independent of time after COVID-19, recoverees had elevated T cell activation signatures and lower expression of innate immune genes including Toll-like receptors in monocytes. Male individuals who had recovered from COVID-19 had coordinately higher innate, influenza-specific plasmablast, and antibody responses after vaccination compared with healthy male individuals and female individuals who had recovered from COVID-19, in part because male recoverees had monocytes with higher IL-15 responses early after vaccination coupled with elevated prevaccination frequencies of 'virtual memory'-like CD8+ T cells poised to produce more IFNγ after IL-15 stimulation. Moreover, the expression of the repressed innate immune genes in monocytes increased by day 1 to day 28 after vaccination in recoverees, therefore moving towards the prevaccination baseline of the healthy control individuals. By contrast, these genes decreased on day 1 and returned to the baseline by day 28 in the control individuals. Our study reveals sex-dimorphic effects of previous mild COVID-19 and suggests that viral infections in humans can establish new immunological set-points that affect future immune responses in an antigen-agnostic manner.
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COVID-19 , Inmunidad Innata , Memoria Inmunológica , Vacunas contra la Influenza , Caracteres Sexuales , Linfocitos T , Vacunación , Femenino , Humanos , Masculino , Linfocitos T CD8-positivos/inmunología , COVID-19/inmunología , Vacunas contra la Influenza/inmunología , Gripe Humana/inmunología , Gripe Humana/prevención & control , Interleucina-15/inmunología , Receptores Toll-Like/inmunología , Linfocitos T/citología , Linfocitos T/inmunología , Monocitos , Inmunidad Innata/genética , Inmunidad Innata/inmunología , Análisis de la Célula Individual , Voluntarios SanosRESUMEN
Betacoronaviruses caused the outbreaks of severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome, as well as the current pandemic of SARS coronavirus 2 (SARS-CoV-2)1-4. Vaccines that elicit protective immunity against SARS-CoV-2 and betacoronaviruses that circulate in animals have the potential to prevent future pandemics. Here we show that the immunization of macaques with nanoparticles conjugated with the receptor-binding domain of SARS-CoV-2, and adjuvanted with 3M-052 and alum, elicits cross-neutralizing antibody responses against bat coronaviruses, SARS-CoV and SARS-CoV-2 (including the B.1.1.7, P.1 and B.1.351 variants). Vaccination of macaques with these nanoparticles resulted in a 50% inhibitory reciprocal serum dilution (ID50) neutralization titre of 47,216 (geometric mean) for SARS-CoV-2, as well as in protection against SARS-CoV-2 in the upper and lower respiratory tracts. Nucleoside-modified mRNAs that encode a stabilized transmembrane spike or monomeric receptor-binding domain also induced cross-neutralizing antibody responses against SARS-CoV and bat coronaviruses, albeit at lower titres than achieved with the nanoparticles. These results demonstrate that current mRNA-based vaccines may provide some protection from future outbreaks of zoonotic betacoronaviruses, and provide a multimeric protein platform for the further development of vaccines against multiple (or all) betacoronaviruses.
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Anticuerpos Neutralizantes/inmunología , Betacoronavirus/inmunología , COVID-19/inmunología , COVID-19/prevención & control , Resfriado Común/prevención & control , Reacciones Cruzadas/inmunología , Pandemias , Vacunas Virales/inmunología , Adyuvantes Inmunológicos , Administración Intranasal , Animales , COVID-19/epidemiología , Vacunas contra la COVID-19/inmunología , Resfriado Común/inmunología , Resfriado Común/virología , Modelos Animales de Enfermedad , Femenino , Humanos , Macaca/inmunología , Masculino , Modelos Moleculares , Nanopartículas/química , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/inmunología , Tráquea , VacunaciónRESUMEN
An overreactive inflammatory response and coagulopathy are observed in patients with severe form of COVID-19. Since increased levels of D-dimer (DD) are associated with coagulopathy in COVID-19, we explored whether DD contributes to the aberrant cytokine responses. Here we show that treatment of healthy human monocytes with DD induced a dose dependent increase in production of pyrogenic mediator, Prostaglandin E2 (PGE2) and inflammatory cytokines, IL-6 and IL-8. The DD-induced PGE2 and inflammatory cytokines were enhanced significantly by co-treatment with immune complexes (IC) of SARS CoV-2 recombinant S protein or of pseudovirus containing SARS CoV-2 S protein (PVCoV-2) coated with spike-specific chimeric monoclonal antibody (MAb) containing mouse variable and human Fc regions. The production of PGE2 and cytokines in monocytes activated with DD and ICs was sensitive to the inhibitors of ß2 integrin and FcγRIIa, and to the inhibitors of calcium signaling, Mitogen-Activated Protein Kinase (MAPK) pathway, and tyrosine-protein kinase. Importantly, strong increase in PGE2 and in IL-6/IL-8/IL-1ß cytokines was observed in monocytes activated with DD in the presence of IC of PVCoV-2 coated with plasma from hospitalized COVID-19 patients but not from healthy donors. The IC of PVCoV-2 with convalescent plasma induced much lower levels of PGE2 and cytokines compared with plasma from hospitalized COVID-19 patients. PGE2 and IL-6/IL-8 cytokines produced in monocytes activated with plasma-containing IC, correlated well with the levels of spike binding antibodies and not with neutralizing antibody titers. Our study suggests that a combination of high levels of DD and high titers of spike-binding antibodies that can form IC with SARS CoV-2 viral particles might accelerate the inflammatory status of lung infiltrating monocytes leading to increased lung pathology in patients with severe form of COVID-19.
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COVID-19 , Monocitos , Animales , Complejo Antígeno-Anticuerpo , COVID-19/terapia , Citocinas/metabolismo , Dinoprostona/metabolismo , Productos de Degradación de Fibrina-Fibrinógeno , Humanos , Inmunización Pasiva , Factores Inmunológicos/metabolismo , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Ratones , Glicoproteína de la Espiga del Coronavirus/metabolismo , Sueroterapia para COVID-19RESUMEN
Passive antibody immunotherapeutics directed against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are promising countermeasures for protection and treatment of coronavirus disease 2019 (COVID-19). SARS-CoV-2 variants of concern (VOCs) and variants of interest (VOIs) can impact the clinical efficacy of immunotherapeutics. A fully human polyclonal antibody immunotherapeutic purified from plasma of transchromosomic (Tc) bovines hyperimmunized with SARS-CoV-2 WA-1 spike (SAB-185) is being assessed for efficacy in a phase 2/3 clinical trial when different circulating SARS-CoV-2 variants predominated. We evaluated antibody binding, avidity maturation, and SARS-CoV-2 VOCs/VOIs virus-neutralizing capacity of convalescent plasma compared with different lots of SAB-185 and individual Tc bovine sera sequentially obtained after each vaccination against Alpha, Epsilon, Iota, Gamma, Beta, Kappa, and Delta variants. In contrast to convalescent plasma, sera and SAB-185 derived from hyperimmunized Tc bovines demonstrated higher antibody avidity and more potent cross-neutralizing activity of VOCs/VOIs. Thus, SAB-185 is a potential promising therapeutic candidate for the treatment of patients infected with SARS-CoV-2 variants.
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COVID-19 , SARS-CoV-2 , Animales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Afinidad de Anticuerpos , COVID-19/terapia , Bovinos , Humanos , Inmunización Pasiva , Inmunoglobulina G , Pruebas de Neutralización , Glicoproteína de la Espiga del Coronavirus , Sueroterapia para COVID-19RESUMEN
Convalescent plasma (CP) have been used for treatment of coronavirus disease 2019 (COVID-19), but their effectiveness varies significantly. Moreover, the impact of CP treatment on the composition of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in COVID-19 patients and antibody markers that differentiate between those who survive and those who succumb to the COVID-19 disease are not well understood. Herein, we performed longitudinal analysis of antibody profile on 115 sequential plasma samples from 16 hospitalized COVID-19 patients treated with either CP or standard of care, only half of them survived. Differential antibody kinetics was observed for antibody binding, immunoglobulin M/immunoglobulin G/immunoglobulin A (IgM/IgG/IgA) distribution, and affinity maturation in "survived" versus "fatal" COVID-19 patients. Surprisingly, CP treatment did not predict survival. Strikingly, marked decline in neutralization titers was observed in the fatal patients prior to death, and convalescent plasma treatment did not reverse this trend. Furthermore, irrespective of CP treatment, higher antibody affinity to the SARS-CoV-2 prefusion spike was associated with survival outcome. Additionally, sustained elevated IgA response was associated with fatal outcome in these COVID-19 patients. These findings propose that treatment of COVID-19 patients with convalescent plasma should be carefully targeted, and effectiveness of treatment may depend on the clinical and immunological status of COVID-19 patients, as well as the quality of the antibodies in the convalescent plasma.
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COVID-19 , SARS-CoV-2 , Anticuerpos Neutralizantes , Anticuerpos Antivirales , COVID-19/terapia , Humanos , Inmunización Pasiva , Sueroterapia para COVID-19RESUMEN
Several next-generation (universal) influenza vaccines and broadly neutralizing antibodies (bNAbs) are in clinical development. Some of these mediate inhibitions of virus replication at the postentry stage or use Fc-dependent mechanisms. Nonneutralizing antibodies have the potential to mediate enhancement of viral infection or disease. In the current study, two monoclonal antibodies (MAbs) 72/8 and 69/1, enhanced respiratory disease (ERD) in mice following H3N2 virus challenge by demonstrating increased lung pathology and changes in lung cytokine/chemokine levels. MAb 78/2 caused changes in the lung viral loads in a dose-dependent manner. Both MAbs increased HA sensitivity to trypsin cleavage at a higher pH range, suggesting MAb-induced conformational changes. pHrodo-labeled virus particles' entry and residence time in the endocytic compartment were tracked during infection of Madin-Darby canine kidney (MDCK) cells. Both MAbs reduced H3N2 virus residence time in the endocytic pathway, suggesting faster virus fusion kinetics. Structurally, 78/2 and 69/1 Fabs bound the globular head or base of the head domain of influenza hemagglutinin (HA), respectively, and induced destabilization of the HA stem domain. Together, this study describes Mab-induced destabilization of the influenza HA stem domain, faster kinetics of influenza virus fusion, and ERD in vivo. The in vivo animal model and in vitro assays described could augment preclinical safety evaluation of antibodies and next-generation influenza vaccines that generate antibodies which do not block influenza virus-receptor interaction.
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Anticuerpos Monoclonales/efectos adversos , Anticuerpos Antivirales/efectos adversos , Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Pulmón/virología , Infecciones por Orthomyxoviridae/virología , Internalización del Virus/efectos de los fármacos , Animales , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/metabolismo , Anticuerpos Antivirales/química , Anticuerpos Antivirales/metabolismo , Sitios de Unión , Perros , Endocitosis/efectos de los fármacos , Endocitosis/inmunología , Femenino , Glicoproteínas Hemaglutininas del Virus de la Influenza/química , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Subtipo H3N2 del Virus de la Influenza A/efectos de los fármacos , Subtipo H3N2 del Virus de la Influenza A/inmunología , Subtipo H3N2 del Virus de la Influenza A/patogenicidad , Pulmón/inmunología , Pulmón/patología , Células de Riñón Canino Madin Darby , Ratones , Ratones Endogámicos BALB C , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/patología , Unión Proteica , Proteolisis , Carga Viral/efectos de los fármacos , Virión/efectos de los fármacos , Virión/inmunología , Virión/patogenicidad , Replicación Viral/efectos de los fármacosRESUMEN
Immunization with mRNA or viral vectors encoding spike with diproline substitutions (S-2P) has provided protective immunity against severe COVID-19 disease. How immunization with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) spike elicits neutralizing antibodies (nAbs) against difficult-to-neutralize variants of concern (VOCs) remains an area of great interest. Here, we compare immunization of macaques with mRNA vaccines expressing ancestral spike either including or lacking diproline substitutions, and show the diproline substitutions were not required for protection against SARS-CoV-2 challenge or induction of broadly neutralizing B cell lineages. One group of nAbs elicited by the ancestral spike lacking diproline substitutions targeted the outer face of the receptor binding domain (RBD), neutralized all tested SARS-CoV-2 VOCs including Omicron XBB.1.5, but lacked cross-Sarbecovirus neutralization. Structural analysis showed that the macaque broad SARS-CoV-2 VOC nAbs bound to the same epitope as a human broad SARS-CoV-2 VOC nAb, DH1193. Vaccine-induced antibodies that targeted the RBD inner face neutralized multiple Sarbecoviruses, protected mice from bat CoV RsSHC014 challenge, but lacked Omicron variant neutralization. Thus, ancestral SARS-CoV-2 spike lacking proline substitutions encoded by nucleoside-modified mRNA can induce B cell lineages binding to distinct RBD sites that either broadly neutralize animal and human Sarbecoviruses or recent Omicron VOCs.
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Respiratory syncytial virus (RSV) vaccines primarily focused on surface fusion (F) protein are under development. Therefore, to identify RSV-F protective epitopes, we evaluated 14 antigenic sites recognized following primary human RSV infection. BALB/c mice were vaccinated with F peptides, F proteins, or RSV-A2, followed by rA2-Line19F challenge. F peptides generated binding antibodies with minimal in vitro neutralization titers. However, several F peptides (including Site II) reduced lung viral loads and lung pathology scores in animals, suggesting partial protection from RSV disease. Interestingly, animals vaccinated with peptides (aa 101-121 and 110-136) spanning the F-p27 sequence, which is only present in unprocessed F0 protein, showed control of viral loads with significantly reduced pathology compared with mock-vaccinated controls. Furthermore, we observed F-p27 expression on the surface of RSV-infected cells as well as lungs from RSV-infected mice. The anti-p27 antibodies demonstrated antibody-dependent cellular cytotoxicity (ADCC) of RSV-infected A549 cells. These findings suggest that p27-mediated immune response may play a role in control of RSV disease in vivo, and F-p27 should be considered for inclusion in an effective RSV vaccine.
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Infecciones por Virus Sincitial Respiratorio , Vacunas contra Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Animales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Ratones , Ratones Endogámicos BALB C , Infecciones por Virus Sincitial Respiratorio/prevención & control , Vacunas contra Virus Sincitial Respiratorio/química , Vacunas contra Virus Sincitial Respiratorio/genética , Virus Sincitial Respiratorio Humano/genética , Proteínas Virales de Fusión/genéticaRESUMEN
Mitochondrial DNA (mtDNA) replication and transcription are of paramount importance to cellular energy metabolism. Mitochondrial RNA polymerase is thought to be the primase for mtDNA replication. However, it is unclear how this enzyme, which normally transcribes long polycistronic RNAs, can produce short RNA oligonucleotides to initiate mtDNA replication. We show that the PPR domain of Drosophila mitochondrial RNA polymerase (PolrMT) has 3'-to-5' exoribonuclease activity, which is indispensable for PolrMT to synthesize short RNA oligonucleotides and prime DNA replication in vitro. An exoribonuclease-deficient mutant, PolrMTE423P, partially restores mitochondrial transcription but fails to support mtDNA replication when expressed in PolrMT-mutant flies, indicating that the exoribonuclease activity is necessary for mtDNA replication. In addition, overexpression of PolrMTE423P in adult flies leads to severe neuromuscular defects and a marked increase in mtDNA transcript errors, suggesting that exoribonuclease activity may contribute to the proofreading of mtDNA transcription.
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Drosophila melanogaster , Exorribonucleasas , Animales , Replicación del ADN/genética , ADN Mitocondrial/genética , ADN Mitocondrial/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Exorribonucleasas/genética , Proteínas Mitocondriales/metabolismo , Oligonucleótidos , ARN/genética , ARN Mitocondrial/genéticaRESUMEN
Mucosal immunity plays an important role in the control of viral respiratory infections like SARS-CoV-2. While systemic immune responses against the SARS-2-CoV-2 have been studied in children, there is no information on mucosal antibody response, especially in the lower respiratory tract of children coronavirus disease 2019 (COVID-19) and post-infectious multisystem inflammatory syndrome in children (MIS-C) against emerging SARS-CoV-2 variants. Therefore, we evaluated neutralizing antibody responses in paired plasma and endotracheal aspirates of pediatric severe, acute COVID-19 or MIS-C patients against SARS-CoV-2 WA1/2020, as well as against variants of concern (VOCs). Neutralizing antibody responses against the SARS-CoV-2 WA1/2020 strain in pediatric plasma were 2-fold or 35-fold higher compared with the matched endotracheal aspirate in COVID-19 or MIS-C patients, respectively. In contrast to plasma, neutralizing antibody responses against the VOCs and variants of interest (VOIs) in endotracheal aspirates were lower, with only one endotracheal aspirate demonstrating neutralizing titers against the Iota, Kappa, Beta, Gamma, and Omicron variants. In conclusion, our findings suggest that children and adolescents with severe COVID-19 or MIS-C have weak mucosal neutralizing antibodies in the trachea against circulating SARS-CoV-2 Omicron and other VOCs, which may have implications for recovery and for re-infection with emerging SARS-CoV-2 variants.
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BACKGROUND: Limited knowledge exists in post-partum women regarding durability of SARS-CoV-2 vaccine-induced antibody responses and their neutralising ability against SARS-CoV-2 variants of concern (VOC). METHODS: We elucidated longitudinal mRNA vaccination-induced antibody profiles of 13 post-partum and 13 non-post-partum women (control). FINDINGS: The antibody neutralisation titres against SARS-CoV-2 WA-1 strain were comparable between post-partum and non-post-partum women and these levels were sustained up to four months post-second vaccination in both groups. However, neutralisation titers declined against several VOCs, including Beta and Delta. Higher antibody binding was observed against SARS-CoV-2 receptor-binding domain (RBD) mutants with key VOC amino acids when tested with post-second vaccination plasma from post-partum women compared with controls. Importantly, post-vaccination plasma antibody affinity against VOCs RBDs was significantly higher in post-partum women compared with controls. INTERPRETATION: This study demonstrates that there is a differential vaccination-induced immune responses in post-partum women compared with non-post-partum women, which could help inform future vaccination strategies for these groups. FUNDING: The antibody characterisation work described in this manuscript was supported by FDA's Medical Countermeasures Initiative (MCMi) grant #OCET 2021-1565 to S.K and intramural FDA-CBER COVID-19 supplemental funds.
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Vacunas contra la COVID-19 , COVID-19 , Anticuerpos Antivirales , Afinidad de Anticuerpos , COVID-19/prevención & control , Femenino , Humanos , Inmunoglobulina G , Periodo Posparto , SARS-CoV-2/genética , Vacunas Sintéticas , Vacunas de ARNmRESUMEN
Viral infections can have profound and durable functional impacts on the immune system. There is an urgent need to characterize the long-term immune effects of SARS-CoV-2 infection given the persistence of symptoms in some individuals and the continued threat of novel variants. Here we use systems immunology, including longitudinal multimodal single cell analysis (surface proteins, transcriptome, and V(D)J sequences) from 33 previously healthy individuals after recovery from mild, non-hospitalized COVID-19 and 40 age- and sex-matched healthy controls with no history of COVID-19 to comparatively assess the post-infection immune status (mean: 151 days after diagnosis) and subsequent innate and adaptive responses to seasonal influenza vaccination. Identification of both sex-specific and -independent temporally stable changes, including signatures of T-cell activation and repression of innate defense/immune receptor genes (e.g., Toll-like receptors) in monocytes, suggest that mild COVID-19 can establish new post-recovery immunological set-points. COVID-19-recovered males had higher innate, influenza-specific plasmablast, and antibody responses after vaccination compared to healthy males and COVID-19-recovered females, partly attributable to elevated pre-vaccination frequencies of a GPR56 expressing CD8+ T-cell subset in male recoverees that are "poised" to produce higher levels of IFNγ upon inflammatory stimulation. Intriguingly, by day 1 post-vaccination in COVID-19-recovered subjects, the expression of the repressed genes in monocytes increased and moved towards the pre-vaccination baseline of healthy controls, suggesting that the acute inflammation induced by vaccination could partly reset the immune states established by mild COVID-19. Our study reveals sex-dimorphic immune imprints and in vivo functional impacts of mild COVID-19 in humans, suggesting that prior COVID-19, and possibly respiratory viral infections in general, could change future responses to vaccination and in turn, vaccines could help reset the immune system after COVID-19, both in an antigen-agnostic manner.
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SARS-CoV-2 infection triggers adaptive immune responses from both T and B cells. However, most studies focus on peripheral blood, which may not fully reflect immune responses in lymphoid tissues at the site of infection. To evaluate both local and systemic adaptive immune responses to SARS-CoV-2, we collected peripheral blood, tonsils, and adenoids from 110 children undergoing tonsillectomy/adenoidectomy during the COVID-19 pandemic and found 24 with evidence of prior SARS-CoV-2 infection, including detectable neutralizing antibodies against multiple viral variants. We identified SARS-CoV-2-specific germinal center (GC) and memory B cells; single cell BCR sequencing showed that these virus-specific B cells were class-switched and somatically hypermutated, with overlapping clones in the adenoids and tonsils. Oropharyngeal tissues from COVID-19-convalescent children showed persistent expansion of GC and anti-viral lymphocyte populations associated with an IFN-γ-type response, with particularly prominent changes in the adenoids, as well as evidence of persistent viral RNA in both tonsil and adenoid tissues of many participants. Our results show robust, tissue-specific adaptive immune responses to SARS-CoV-2 in the upper respiratory tract of children weeks to months after acute infection, providing evidence of persistent localized immunity to this respiratory virus.
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Severe acute respiratory syndrome coronaviruses 1 (SARS-CoV) and 2 (SARS-CoV-2), including SARS-CoV-2 variants of concern, can cause deadly infections. The mortality associated with sarbecovirus infection underscores the importance of developing broadly effective countermeasures against them, which could be key in the prevention and mitigation of current and future zoonotic events. Here, we demonstrate the neutralization of SARS-CoV; bat coronaviruses WIV-1 and RsSHC014; and SARS-CoV-2 variants D614G, B.1.1.7, B.1.351, P.1, B.1.429, B.1.526, B.1.617.1, and B.1.617.2 by a receptor binding domain (RBD)specific human antibody, DH1047. Prophylactic and therapeutic treatment with DH1047 was protective against SARS-CoV, WIV-1, RsSHC014, and SARS-CoV-2 B.1.351 infection in mice. Binding and structural analysis showed high affinity binding of DH1047 to an epitope that is highly conserved among sarbecoviruses. Thus, DH1047 is a broadly protective antibody that can prevent infection and mitigate outbreaks caused by SARS-related strains and SARS-CoV-2 variants. Our results also suggest that the conserved RBD epitope bound by DH1047 is a rational target for a universal sarbecovirus vaccine.
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COVID-19 , SARS-CoV-2 , Animales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Humanos , Ratones , Glicoproteína de la Espiga del CoronavirusRESUMEN
Coronavirus vaccines that are highly effective against current and anticipated SARS-CoV-2 variants are needed to control COVID-19. We previously reported a receptor-binding domain (RBD)-sortase A-conjugated ferritin nanoparticle (scNP) vaccine that induced neutralizing antibodies against SARS-CoV-2 and pre-emergent sarbecoviruses and protected non-human primates (NHPs) from SARS-CoV-2 WA-1 infection. Here, we find the RBD-scNP induced neutralizing antibodies in NHPs against pseudoviruses of SARS-CoV and SARS-CoV-2 variants including 614G, Beta, Delta, Omicron BA.1, BA.2, BA.2.12.1, and BA.4/BA.5, and a designed variant with escape mutations, PMS20. Adjuvant studies demonstrate variant neutralization titers are highest with 3M-052-aqueous formulation (AF). Immunization twice with RBD-scNPs protect NHPs from SARS-CoV-2 WA-1, Beta, and Delta variant challenge, and protect mice from challenges of SARS-CoV-2 Beta variant and two other heterologous sarbecoviruses. These results demonstrate the ability of RBD-scNPs to induce broad neutralization of SARS-CoV-2 variants and to protect animals from multiple different SARS-related viruses. Such a vaccine could provide broad immunity to SARS-CoV-2 variants.
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COVID-19 , Nanopartículas , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo , Vacunas Virales , Ratones , Animales , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus , Anticuerpos Antivirales , Ratones Endogámicos BALB C , COVID-19/prevención & control , Anticuerpos Neutralizantes/química , FerritinasRESUMEN
Neutralization capacity of antibodies against Omicron after a prior SARS-CoV-2 infection in children and adolescents is not well studied. Therefore, we evaluated virus-neutralizing capacity against SARS-CoV-2 Alpha, Beta, Gamma, Delta and Omicron variants by age-stratified analyses (<5, 5-11, 12-21 years) in 177 pediatric patients hospitalized with severe acute COVID-19, acute MIS-C, and in convalescent samples of outpatients with mild COVID-19 during 2020 and early 2021. Across all patients, less than 10% show neutralizing antibody titers against Omicron. Children <5 years of age hospitalized with severe acute COVID-19 have lower neutralizing antibodies to SARS-CoV-2 variants compared with patients >5 years of age. As expected, convalescent pediatric COVID-19 and MIS-C cohorts demonstrate higher neutralization titers than hospitalized acute COVID-19 patients. Overall, children and adolescents show some loss of cross-neutralization against all variants, with the most pronounced loss against Omicron. In contrast to SARS-CoV-2 infection, children vaccinated twice demonstrated higher titers against Alpha, Beta, Gamma, Delta and Omicron. These findings can influence transmission, re-infection and the clinical disease outcome from emerging SARS-CoV-2 variants and supports the need for vaccination in children.
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COVID-19 , SARS-CoV-2 , Adolescente , Anticuerpos Antivirales , COVID-19/complicaciones , Niño , Preescolar , Humanos , Glicoproteínas de Membrana , Pruebas de Neutralización , Glicoproteína de la Espiga del Coronavirus , Síndrome de Respuesta Inflamatoria Sistémica , Proteínas del Envoltorio ViralRESUMEN
Coronavirus vaccines that are highly effective against SARS-CoV-2 variants are needed to control the current pandemic. We previously reported a receptor-binding domain (RBD) sortase A-conjugated ferritin nanoparticle (RBD-scNP) vaccine that induced neutralizing antibodies against SARS-CoV-2 and pre-emergent sarbecoviruses and protected monkeys from SARS-CoV-2 WA-1 infection. Here, we demonstrate SARS-CoV-2 RBD-scNP immunization induces potent neutralizing antibodies in non-human primates (NHPs) against all eight SARS-CoV-2 variants tested including the Beta, Delta, and Omicron variants. The Omicron variant was neutralized by RBD-scNP-induced serum antibodies with a mean of 10.6-fold reduction of ID50 titers compared to SARS-CoV-2 D614G. Immunization with RBD-scNPs protected NHPs from SARS-CoV-2 WA-1, Beta, and Delta variant challenge, and protected mice from challenges of SARS-CoV-2 Beta variant and two other heterologous sarbecoviruses. These results demonstrate the ability of RBD-scNPs to induce broad neutralization of SARS-CoV-2 variants and to protect NHPs and mice from multiple different SARS-related viruses. Such a vaccine could provide the needed immunity to slow the spread of and reduce disease caused by SARS-CoV-2 variants such as Delta and Omicron.
RESUMEN
Mucosal immunity plays a key role in prevention of SARS-CoV-2 virus spread to the lungs. In this study, we evaluated systemic and mucosal immune signatures in asymptomatic SARS-CoV-2infected versus symptomatic COVID-19 adults compared with RSV-infected adults. Matched serum and nasal wash pairs were subjected to cytokine/chemokine analyses and comprehensive antibody profiling including epitope repertoire analyses, antibody kinetics to SARS-CoV-2 prefusion spike and spike RBD mutants, and neutralization of SARS-CoV-2 variants of concern. The data suggest independent evolution of antibody responses in the mucosal sites as reflected in differential IgM/IgG/IgA epitope repertoire compared with serum. Antibody affinity against SARS-CoV-2 prefusion spike for both serum and nasal washes was significantly higher in asymptomatic adults compared with symptomatic COVID-19 patients. Last, the cytokine/chemokine responses in the nasal washes were more robust than in serum. These data underscore the importance of evaluating mucosal immune responses for better therapeutics and vaccines against SARS-CoV-2.