RESUMEN
COVID survivors frequently experience lingering neurological symptoms that resemble cancer-therapy-related cognitive impairment, a syndrome for which white matter microglial reactivity and consequent neural dysregulation is central. Here, we explored the neurobiological effects of respiratory SARS-CoV-2 infection and found white-matter-selective microglial reactivity in mice and humans. Following mild respiratory COVID in mice, persistently impaired hippocampal neurogenesis, decreased oligodendrocytes, and myelin loss were evident together with elevated CSF cytokines/chemokines including CCL11. Systemic CCL11 administration specifically caused hippocampal microglial reactivity and impaired neurogenesis. Concordantly, humans with lasting cognitive symptoms post-COVID exhibit elevated CCL11 levels. Compared with SARS-CoV-2, mild respiratory influenza in mice caused similar patterns of white-matter-selective microglial reactivity, oligodendrocyte loss, impaired neurogenesis, and elevated CCL11 at early time points, but after influenza, only elevated CCL11 and hippocampal pathology persisted. These findings illustrate similar neuropathophysiology after cancer therapy and respiratory SARS-CoV-2 infection which may contribute to cognitive impairment following even mild COVID.
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COVID-19 , Gripe Humana , Neoplasias , Animales , Humanos , Gripe Humana/patología , Ratones , Microglía/patología , Vaina de Mielina , Neoplasias/patología , SARS-CoV-2RESUMEN
Severe COVID-19 is characterized by persistent lung inflammation, inflammatory cytokine production, viral RNA and a sustained interferon (IFN) response, all of which are recapitulated and required for pathology in the SARS-CoV-2-infected MISTRG6-hACE2 humanized mouse model of COVID-19, which has a human immune system1-20. Blocking either viral replication with remdesivir21-23 or the downstream IFN-stimulated cascade with anti-IFNAR2 antibodies in vivo in the chronic stages of disease attenuates the overactive immune inflammatory response, especially inflammatory macrophages. Here we show that SARS-CoV-2 infection and replication in lung-resident human macrophages is a critical driver of disease. In response to infection mediated by CD16 and ACE2 receptors, human macrophages activate inflammasomes, release interleukin 1 (IL-1) and IL-18, and undergo pyroptosis, thereby contributing to the hyperinflammatory state of the lungs. Inflammasome activation and the accompanying inflammatory response are necessary for lung inflammation, as inhibition of the NLRP3 inflammasome pathway reverses chronic lung pathology. Notably, this blockade of inflammasome activation leads to the release of infectious virus by the infected macrophages. Thus, inflammasomes oppose host infection by SARS-CoV-2 through the production of inflammatory cytokines and suicide by pyroptosis to prevent a productive viral cycle.
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COVID-19 , Inflamasomas , Macrófagos , SARS-CoV-2 , Enzima Convertidora de Angiotensina 2 , Animales , COVID-19/patología , COVID-19/fisiopatología , COVID-19/virología , Humanos , Inflamasomas/metabolismo , Interleucina-1 , Interleucina-18 , Pulmón/patología , Pulmón/virología , Macrófagos/metabolismo , Macrófagos/patología , Macrófagos/virología , Ratones , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Neumonía/metabolismo , Neumonía/virología , Piroptosis , Receptores de IgG , SARS-CoV-2/metabolismo , SARS-CoV-2/patogenicidadRESUMEN
COVID-19 manifests with a wide spectrum of clinical phenotypes that are characterized by exaggerated and misdirected host immune responses1-6. Although pathological innate immune activation is well-documented in severe disease1, the effect of autoantibodies on disease progression is less well-defined. Here we use a high-throughput autoantibody discovery technique known as rapid extracellular antigen profiling7 to screen a cohort of 194 individuals infected with SARS-CoV-2, comprising 172 patients with COVID-19 and 22 healthcare workers with mild disease or asymptomatic infection, for autoantibodies against 2,770 extracellular and secreted proteins (members of the exoproteome). We found that patients with COVID-19 exhibit marked increases in autoantibody reactivities as compared to uninfected individuals, and show a high prevalence of autoantibodies against immunomodulatory proteins (including cytokines, chemokines, complement components and cell-surface proteins). We established that these autoantibodies perturb immune function and impair virological control by inhibiting immunoreceptor signalling and by altering peripheral immune cell composition, and found that mouse surrogates of these autoantibodies increase disease severity in a mouse model of SARS-CoV-2 infection. Our analysis of autoantibodies against tissue-associated antigens revealed associations with specific clinical characteristics. Our findings suggest a pathological role for exoproteome-directed autoantibodies in COVID-19, with diverse effects on immune functionality and associations with clinical outcomes.
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Autoanticuerpos/análisis , Autoanticuerpos/inmunología , COVID-19/inmunología , COVID-19/metabolismo , Proteoma/inmunología , Proteoma/metabolismo , Animales , Antígenos de Superficie/inmunología , COVID-19/patología , COVID-19/fisiopatología , Estudios de Casos y Controles , Proteínas del Sistema Complemento/inmunología , Citocinas/inmunología , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Ratones , Especificidad de Órganos/inmunologíaRESUMEN
Respiratory virus infections in humans cause a broad-spectrum of diseases that result in substantial morbidity and mortality annually worldwide. To reduce the global burden of respiratory viral diseases, preventative and therapeutic interventions that are accessible and effective are urgently needed, especially in countries that are disproportionately affected. Repurposing generic medicine has the potential to bring new treatments for infectious diseases to patients efficiently and equitably. In this study, we found that intranasal delivery of neomycin, a generic aminoglycoside antibiotic, induces the expression of interferon-stimulated genes (ISGs) in the nasal mucosa that is independent of the commensal microbiota. Prophylactic or therapeutic administration of neomycin provided significant protection against upper respiratory infection and lethal disease in a mouse model of COVID-19. Furthermore, neomycin treatment protected Mx1 congenic mice from upper and lower respiratory infections with a highly virulent strain of influenza A virus. In Syrian hamsters, neomycin treatment potently mitigated contact transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In healthy humans, intranasal application of neomycin-containing Neosporin ointment was well tolerated and effective at inducing ISG expression in the nose in a subset of participants. These findings suggest that neomycin has the potential to be harnessed as a host-directed antiviral strategy for the prevention and treatment of respiratory viral infections.
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Administración Intranasal , Antivirales , Neomicina , SARS-CoV-2 , Animales , Neomicina/farmacología , Neomicina/administración & dosificación , Ratones , Humanos , Antivirales/farmacología , Antivirales/administración & dosificación , SARS-CoV-2/inmunología , SARS-CoV-2/efectos de los fármacos , COVID-19/inmunología , COVID-19/prevención & control , COVID-19/virología , Infecciones del Sistema Respiratorio/inmunología , Infecciones del Sistema Respiratorio/tratamiento farmacológico , Infecciones del Sistema Respiratorio/virología , Infecciones del Sistema Respiratorio/prevención & control , Mucosa Nasal/inmunología , Mucosa Nasal/virología , Mucosa Nasal/efectos de los fármacos , Modelos Animales de Enfermedad , Tratamiento Farmacológico de COVID-19 , Mesocricetus , Femenino , Virus de la Influenza A/efectos de los fármacos , Virus de la Influenza A/inmunologíaRESUMEN
There is increasing evidence that coronavirus disease 2019 (COVID-19) produces more severe symptoms and higher mortality among men than among women1-5. However, whether immune responses against severe acute respiratory syndrome coronavirus (SARS-CoV-2) differ between sexes, and whether such differences correlate with the sex difference in the disease course of COVID-19, is currently unknown. Here we examined sex differences in viral loads, SARS-CoV-2-specific antibody titres, plasma cytokines and blood-cell phenotyping in patients with moderate COVID-19 who had not received immunomodulatory medications. Male patients had higher plasma levels of innate immune cytokines such as IL-8 and IL-18 along with more robust induction of non-classical monocytes. By contrast, female patients had more robust T cell activation than male patients during SARS-CoV-2 infection. Notably, we found that a poor T cell response negatively correlated with patients' age and was associated with worse disease outcome in male patients, but not in female patients. By contrast, higher levels of innate immune cytokines were associated with worse disease progression in female patients, but not in male patients. These findings provide a possible explanation for the observed sex biases in COVID-19, and provide an important basis for the development of a sex-based approach to the treatment and care of male and female patients with COVID-19.
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COVID-19/inmunología , Citocinas/inmunología , Inmunidad Innata/inmunología , SARS-CoV-2/inmunología , Caracteres Sexuales , Linfocitos T/inmunología , COVID-19/sangre , COVID-19/virología , Quimiocinas/sangre , Quimiocinas/inmunología , Estudios de Cohortes , Citocinas/sangre , Progresión de la Enfermedad , Femenino , Humanos , Activación de Linfocitos , Masculino , Monocitos/inmunología , Fenotipo , Pronóstico , ARN Viral/análisis , SARS-CoV-2/patogenicidad , Carga ViralRESUMEN
Recent studies have provided insights into the pathogenesis of coronavirus disease 2019 (COVID-19)1-4. However, the longitudinal immunological correlates of disease outcome remain unclear. Here we serially analysed immune responses in 113 patients with moderate or severe COVID-19. Immune profiling revealed an overall increase in innate cell lineages, with a concomitant reduction in T cell number. An early elevation in cytokine levels was associated with worse disease outcomes. Following an early increase in cytokines, patients with moderate COVID-19 displayed a progressive reduction in type 1 (antiviral) and type 3 (antifungal) responses. By contrast, patients with severe COVID-19 maintained these elevated responses throughout the course of the disease. Moreover, severe COVID-19 was accompanied by an increase in multiple type 2 (anti-helminths) effectors, including interleukin-5 (IL-5), IL-13, immunoglobulin E and eosinophils. Unsupervised clustering analysis identified four immune signatures, representing growth factors (A), type-2/3 cytokines (B), mixed type-1/2/3 cytokines (C), and chemokines (D) that correlated with three distinct disease trajectories. The immune profiles of patients who recovered from moderate COVID-19 were enriched in tissue reparative growth factor signature A, whereas the profiles of those with who developed severe disease had elevated levels of all four signatures. Thus, we have identified a maladapted immune response profile associated with severe COVID-19 and poor clinical outcome, as well as early immune signatures that correlate with divergent disease trajectories.
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Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/fisiopatología , Citocinas/análisis , Neumonía Viral/inmunología , Neumonía Viral/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , COVID-19 , Análisis por Conglomerados , Citocinas/inmunología , Eosinófilos/inmunología , Femenino , Humanos , Inmunoglobulina E/análisis , Inmunoglobulina E/inmunología , Interleucina-13/análisis , Interleucina-13/inmunología , Interleucina-5/análisis , Interleucina-5/inmunología , Masculino , Persona de Mediana Edad , Pandemias , Linfocitos T/citología , Linfocitos T/inmunología , Carga Viral , Adulto JovenRESUMEN
COVID-19 is a global crisis of unimagined dimensions. Currently, Remedesivir is only fully licensed FDA therapeutic. A major target of the vaccine effort is the SARS-CoV-2 spike-hACE2 interaction, and assessment of efficacy relies on time consuming neutralization assay. Here, we developed a cell fusion assay based upon spike-hACE2 interaction. The system was tested by transient co-transfection of 293T cells, which demonstrated good correlation with standard spike pseudotyping for inhibition by sera and biologics. Then established stable cell lines were very well behaved and gave even better correlation with pseudotyping results, after a short, overnight co-incubation. Results with the stable cell fusion assay also correlated well with those of a live virus assay. In summary we have established a rapid, reliable, and reproducible cell fusion assay that will serve to complement the other neutralization assays currently in use, is easy to implement in most laboratories, and may serve as the basis for high throughput screens to identify inhibitors of SARS-CoV-2 virus-cell binding and entry.
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Enzima Convertidora de Angiotensina 2/metabolismo , Bioensayo/métodos , COVID-19/virología , Receptores de Coronavirus/metabolismo , SARS-CoV-2/fisiología , Glicoproteína de la Espiga del Coronavirus/metabolismo , Enzima Convertidora de Angiotensina 2/genética , COVID-19/sangre , Fusión Celular , Células HEK293 , Humanos , Receptores de Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/genética , Transfección , Acoplamiento ViralRESUMEN
The current quantitative reverse transcription PCR (RT-qPCR) assay recommended for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing in the United States requires analysis of 3 genomic targets per sample: 2 viral and 1 host. To simplify testing and reduce the volume of required reagents, we devised a multiplex RT-qPCR assay to detect SARS-CoV-2 in a single reaction. We used existing N1, N2, and RP primer and probe sets by the Centers for Disease Control and Prevention, but substituted fluorophores to allow multiplexing of the assay. The cycle threshold (Ct) values of our multiplex RT-qPCR were comparable to those obtained by the single assay adapted for research purposes. Low copy numbers (≥500 copies/reaction) of SARS-CoV-2 RNA were consistently detected by the multiplex RT-qPCR. Our novel multiplex RT-qPCR improves upon current single diagnostics by saving reagents, costs, time, and labor.
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Betacoronavirus/genética , Técnicas de Laboratorio Clínico/métodos , Infecciones por Coronavirus/diagnóstico , Reacción en Cadena de la Polimerasa Multiplex/normas , Neumonía Viral/diagnóstico , ARN Viral/genética , Juego de Reactivos para Diagnóstico/normas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/normas , Betacoronavirus/patogenicidad , COVID-19 , Prueba de COVID-19 , Estudios de Casos y Controles , Técnicas de Laboratorio Clínico/normas , Infecciones por Coronavirus/virología , Cartilla de ADN/normas , Células HEK293 , Humanos , Límite de Detección , Nasofaringe/virología , Pandemias , Neumonía Viral/virología , SARS-CoV-2 , Estados UnidosRESUMEN
BACKGROUND: The underlying immunologic deficiencies enabling severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection are currently unknown. We describe deep longitudinal immune profiling of a transplant recipient hospitalized twice for coronavirus disease 2019 (COVID-19). METHODS: A 66-year-old male renal transplant recipient was hospitalized with COVID-19 March 2020 then readmitted to the hospital with COVID-19 233 days after initial diagnosis. Virologic and immunologic investigations were performed on samples from the primary and secondary infections. RESULTS: Whole viral genome sequencing and phylogenetic analysis revealed that viruses causing both infections were caused by distinct genetic lineages without evidence of immune escape mutations. Longitudinal comparison of cellular and humoral responses during primary SARS-CoV-2 infection revealed that this patient responded to the primary infection with low neutralization titer anti-SARS-CoV-2 antibodies that were likely present at the time of reinfection. CONCLUSIONS: The development of neutralizing antibodies and humoral memory responses in this patient failed to confer protection against reinfection, suggesting that they were below a neutralizing titer threshold or that additional factors may be required for efficient prevention of SARS-CoV-2 reinfection. Development of poorly neutralizing antibodies may have been due to profound and relatively specific reduction in naive CD4 T-cell pools. Seropositivity alone may not be a perfect correlate of protection in immunocompromised patients.
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COVID-19 , Reinfección , Receptores de Trasplantes , Anciano , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , COVID-19/inmunología , Humanos , Masculino , Trasplante de Órganos , Filogenia , Reinfección/inmunología , Reinfección/virología , SARS-CoV-2/genéticaRESUMEN
We introduce two large-scale resources for functional analysis of microRNA (miRNA): a decoy library for inhibiting miRNA function and a sensor library for monitoring microRNA activity. To take advantage of the sensor library, we developed a high-throughput assay called Sensor-seq to simultaneously quantify the activity of hundreds of miRNAs. Using this approach, we show that only the most abundant miRNAs in a cell mediate target suppression. Over 60% of detected miRNAs had no discernible activity, which indicated that the functional 'miRNome' of a cell is considerably smaller than currently inferred from profiling studies. Moreover, some highly expressed miRNAs exhibited relatively weak activity, which in some cases correlated with a high target-to-miRNA ratio or increased nuclear localization of the miRNA. Finally, we show that the miRNA decoy library can be used for pooled loss-of-function studies. These tools are valuable resources for studying miRNA biology and for miRNA-based therapeutics.
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Técnicas Biosensibles , Biblioteca de Genes , Vectores Genéticos/genética , Ensayos Analíticos de Alto Rendimiento , MicroARNs/genética , MicroARNs/metabolismo , Animales , Humanos , MicroARNs/antagonistas & inhibidoresRESUMEN
Hepatitis C virus (HCV) is a major cause of liver disease worldwide. A better understanding of its life cycle, including the process of host cell entry, is important for the development of HCV therapies and model systems. Based on the requirement for numerous host factors, including the two tight junction proteins claudin-1 (CLDN1) and occludin (OCLN), HCV cell entry has been proposed to be a multi-step process. The lack of OCLN-specific inhibitors has prevented a comprehensive analysis of this process. To study the role of OCLN in HCV cell entry, we created OCLN mutants whose HCV cell entry activities could be inhibited by antibodies. These mutants were expressed in polarized HepG2 cells engineered to support the complete HCV life cycle by CD81 and miR-122 expression and synchronized infection assays were performed to define the kinetics of HCV cell entry. During these studies, OCLN utilization differences between HCV isolates were observed, supporting a model that HCV directly interacts with OCLN. In HepG2 cells, both HCV cell entry and tight junction formation were impaired by OCLN silencing and restored by expression of antibody regulatable OCLN mutant. Synchronized infection assays showed that glycosaminoglycans and SR-BI mediated host cell binding, while CD81, CLDN1 and OCLN all acted sequentially at a post-binding stage prior to endosomal acidification. These results fit a model where the tight junction region is the last to be encountered by the virion prior to internalization.
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Anticuerpos Bloqueadores/farmacología , Hepacivirus/efectos de los fármacos , Ocludina/inmunología , Internalización del Virus/efectos de los fármacos , Silenciador del Gen , Células Hep G2 , Hepacivirus/genética , Hepacivirus/patogenicidad , Interacciones Huésped-Patógeno , Humanos , MicroARNs/metabolismo , Mutación , Ocludina/genética , Tetraspanina 28/metabolismo , Uniones Estrechas , Factores de Tiempo , Virión/patogenicidad , Virión/fisiología , Replicación ViralRESUMEN
UNLABELLED: Hepatitis C virus (HCV) exposure leads to persistent life-long infections characterized by chronic inflammation often developing into cirrhosis and hepatocellular carcinoma. The mechanism by which HCV remains in the liver while inducing an inflammatory and antiviral response remains unclear. Though the innate immune response to HCV in patients seems to be quite active, HCV has been shown in cell culture to employ a diverse array of innate immune antagonists, which suggests that current model systems to study interactions between HCV and the innate immune system are not representative of what happens in vivo. We recently showed that hepatoma-derived HepG2 cells support the entire HCV life cycle if the liver-specific microRNA, miR-122, is expressed along with the entry factor, CD81 (termed HepG2-HFL cells). We found that there was a striking difference in these cells' ability to sustain HCV infection and spread when compared with Huh-7 and Huh-7.5 cells. Additionally, HepG2-HFL cells exhibited a more robust antiviral response when challenged with other RNA viruses and viral mimetics than Huh-7 and Huh-7.5 cells. HCV infection elicited a potent interferon-lambda (IFN-λ), IFN-stimulated gene, and cytokine response in HepG2-HFL cells, but not in Huh-7 cells, suggesting that HepG2-HFL cells more faithfully recapitulate the innate immune response to HCV infection in vivo. Using this model, we found that blocking the retinoic acid-inducible gene I (RIG-I)-like receptor pathway or the IFN-λ-signaling pathway promoted HCV infection and spread in HepG2-HFL cells. CONCLUSION: HepG2-HFL cells represent a new system to study the interaction between HCV and the innate immune system, solidifying the importance of IFN-λ in hepatic response to HCV infection and revealing non-redundant roles of RIG-I and melanoma differentiation-associated protein 5 in HCV recognition and repression of infection.
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Células Hep G2/metabolismo , Células Hep G2/virología , Hepacivirus/fisiología , Hepatitis C/metabolismo , Hepatitis C/fisiopatología , Inmunidad Innata/fisiología , Interleucinas/metabolismo , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/virología , Línea Celular Tumoral , Citocinas/metabolismo , Proteína 58 DEAD Box , ARN Helicasas DEAD-box/metabolismo , Células Hep G2/patología , Hepatitis C/patología , Humanos , Helicasa Inducida por Interferón IFIH1 , Interferones , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/virología , MicroARNs/metabolismo , Receptores Inmunológicos , Transducción de Señal/fisiología , Replicación Viral/fisiologíaRESUMEN
Circulating bat coronaviruses represent a pandemic threat. However, our understanding of bat coronavirus pathogenesis and transmission potential is limited by the lack of phenotypically characterized strains. We created molecular clones for the two closest known relatives of SARS-CoV-2, BANAL-52 and BANAL-236. We demonstrated that BANAL-CoVs and SARS-CoV-2 have similar replication kinetics in human bronchial epithelial cells. However, BANAL-CoVs have impaired replication in human nasal epithelial cells and in the upper airway of mice. We also observed reduced pathogenesis in mice and diminished transmission in hamsters. Further, we observed that diverse bat coronaviruses evade interferon and downregulate major histocompatibility complex class I. Collectively, our study demonstrates that despite high genetic similarity across bat coronaviruses, prediction of pandemic potential of a virus necessitates functional characterization. Finally, the restriction of bat coronavirus replication in the upper airway highlights that transmission potential and innate immune restriction can be uncoupled in this high-risk family of emerging viruses.
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COVID-19 , Quirópteros , Inmunidad Innata , SARS-CoV-2 , Replicación Viral , Animales , Humanos , SARS-CoV-2/inmunología , SARS-CoV-2/genética , SARS-CoV-2/fisiología , Quirópteros/virología , Quirópteros/inmunología , COVID-19/transmisión , COVID-19/virología , COVID-19/inmunología , Ratones , Cricetinae , Evasión Inmune , Células Epiteliales/virología , Células Epiteliales/inmunología , Infecciones por Coronavirus/transmisión , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/virología , Coronavirus/inmunología , Coronavirus/genética , Coronavirus/clasificación , Coronavirus/fisiología , Coronavirus/patogenicidad , Línea Celular , FemeninoRESUMEN
An inhalable platform for messenger RNA (mRNA) therapeutics would enable minimally invasive and lung-targeted delivery for a host of pulmonary diseases. Development of lung-targeted mRNA therapeutics has been limited by poor transfection efficiency and risk of vehicle-induced pathology. Here, we report an inhalable polymer-based vehicle for delivery of therapeutic mRNAs to the lung. We optimized biodegradable poly(amine-co-ester) (PACE) polyplexes for mRNA delivery using end-group modifications and polyethylene glycol. These polyplexes achieved high transfection of mRNA throughout the lung, particularly in epithelial and antigen-presenting cells. We applied this technology to develop a mucosal vaccine for severe acute respiratory syndrome coronavirus 2 and found that intranasal vaccination with spike protein-encoding mRNA polyplexes induced potent cellular and humoral adaptive immunity and protected susceptible mice from lethal viral challenge. Together, these results demonstrate the translational potential of PACE polyplexes for therapeutic delivery of mRNA to the lungs.
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COVID-19 , Nanopartículas , Animales , Ratones , Polímeros , ARN Mensajero/genética , COVID-19/prevención & control , Pulmón , VacunaciónRESUMEN
The liver-specific microRNA miR-122 is required for efficient hepatitis C virus (HCV) RNA replication both in cell culture and in vivo. In addition, nonhepatic cells have been rendered more efficient at supporting this stage of the HCV life cycle by miR-122 expression. This study investigated how miR-122 influences HCV replication in the miR-122-deficient HepG2 cell line. Expression of this microRNA in HepG2 cells permitted efficient HCV RNA replication and infectious virion production. When a missing HCV receptor is also expressed, these cells efficiently support viral entry and thus the entire HCV life cycle.
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Expresión Génica , Hepacivirus/fisiología , Hepatocitos/virología , MicroARNs/biosíntesis , Replicación Viral , Células Hep G2 , Hepacivirus/crecimiento & desarrollo , Humanos , Internalización del Virus , Liberación del VirusRESUMEN
Coronavirus disease 2019 (COVID-19) is an infectious disease that can present as an uncontrolled, hyperactive immune response, causing severe immunological injury. Existing rodent models do not recapitulate the sustained immunopathology of patients with severe disease. Here we describe a humanized mouse model of COVID-19 that uses adeno-associated virus to deliver human ACE2 to the lungs of humanized MISTRG6 mice. This model recapitulates innate and adaptive human immune responses to severe acute respiratory syndrome coronavirus 2 infection up to 28 days after infection, with key features of chronic COVID-19, including weight loss, persistent viral RNA, lung pathology with fibrosis, a human inflammatory macrophage response, a persistent interferon-stimulated gene signature and T cell lymphopenia. We used this model to study two therapeutics on immunopathology, patient-derived antibodies and steroids and found that the same inflammatory macrophages crucial to containing early infection later drove immunopathology. This model will enable evaluation of COVID-19 disease mechanisms and treatments.
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COVID-19 , Animales , Antivirales , Modelos Animales de Enfermedad , Humanos , Interferones , Pulmón/patología , RatonesRESUMEN
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has highlighted the need for vaccines that not only prevent disease but also prevent transmission. Parenteral vaccines induce robust systemic immunity but poor immunity at the respiratory mucosa. We developed a vaccine strategy that we call "prime and spike," which leverages existing immunity generated by primary vaccination (prime) to elicit mucosal immune memory within the respiratory tract by using unadjuvanted intranasal spike boosters (spike). We show that prime and spike induces robust resident memory B and T cell responses, induces immunoglobulin A at the respiratory mucosa, boosts systemic immunity, and completely protects mice with partial immunity from lethal SARS-CoV-2 infection. Using divergent spike proteins, prime and spike enables the induction of cross-reactive immunity against sarbecoviruses.
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Vacunas contra la COVID-19 , COVID-19 , Inmunidad Mucosa , Memoria Inmunológica , Células B de Memoria , Células T de Memoria , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Animales , Ratones , Administración Intranasal , Anticuerpos Antivirales , COVID-19/prevención & control , COVID-19/transmisión , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Vacunación/métodos , Vacunas contra la COVID-19/administración & dosificación , Vacunas contra la COVID-19/inmunología , Inmunoglobulina A , Células B de Memoria/inmunología , Células T de Memoria/inmunologíaRESUMEN
An inhalable platform for mRNA therapeutics would enable minimally invasive and lung targeted delivery for a host of pulmonary diseases. Development of lung targeted mRNA therapeutics has been limited by poor transfection efficiency and risk of vehicle-induced pathology. Here we report an inhalable polymer-based vehicle for delivery of therapeutic mRNAs to the lung. We optimized biodegradable poly(amine-co-ester) polyplexes for mRNA delivery using end group modifications and polyethylene glycol. Our polyplexes achieved high transfection of mRNA throughout the lung, particularly in epithelial and antigen-presenting cells. We applied this technology to develop a mucosal vaccine for SARS-CoV-2. Intranasal vaccination with spike protein mRNA polyplexes induced potent cellular and humoral adaptive immunity and protected K18-hACE2 mice from lethal viral challenge. One-sentence summary: Inhaled polymer nanoparticles (NPs) achieve high mRNA expression in the lung and induce protective immunity against SARS-CoV-2.