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A comprehensive understanding of host dependency factors for SARS-CoV-2 remains elusive. Here, we map alterations in host lipids following SARS-CoV-2 infection using nontargeted lipidomics. We find that SARS-CoV-2 rewires host lipid metabolism, significantly altering hundreds of lipid species to effectively establish infection. We correlate these changes with viral protein activity by transfecting human cells with each viral protein and performing lipidomics. We find that lipid droplet plasticity is a key feature of infection and that viral propagation can be blocked by small-molecule glycerolipid biosynthesis inhibitors. We find that this inhibition was effective against the main variants of concern (alpha, beta, gamma, and delta), indicating that glycerolipid biosynthesis is a conserved host dependency factor that supports this evolving virus.
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COVID-19 , SARS-CoV-2 , Humanos , Lípidos , Proteínas ViralesRESUMEN
The spike glycoprotein of SARS-CoV-2 engages with human ACE 2 to facilitate infection. Here, we describe an alpaca-derived heavy chain antibody fragment (VHH), saRBD-1, that disrupts this interaction by competitively binding to the spike protein receptor-binding domain. We further generated an engineered bivalent nanobody construct engineered by a flexible linker and a dimeric Fc conjugated nanobody construct. Both multivalent nanobodies blocked infection at picomolar concentrations and demonstrated no loss of potency against emerging variants of concern including Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Epsilon (B.1.427/429), and Delta (B.1.617.2). saRBD-1 tolerates elevated temperature, freeze-drying, and nebulization, making it an excellent candidate for further development into a therapeutic approach for COVID-19.
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As a complement to vaccines, small-molecule therapeutic agents are needed to treat or prevent infections by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and its variants, which cause COVID-19. Affinity selection-mass spectrometry was used for the discovery of botanical ligands to the SARS-CoV-2 spike protein. Cannabinoid acids from hemp (Cannabis sativa) were found to be allosteric as well as orthosteric ligands with micromolar affinity for the spike protein. In follow-up virus neutralization assays, cannabigerolic acid and cannabidiolic acid prevented infection of human epithelial cells by a pseudovirus expressing the SARS-CoV-2 spike protein and prevented entry of live SARS-CoV-2 into cells. Importantly, cannabigerolic acid and cannabidiolic acid were equally effective against the SARS-CoV-2 alpha variant B.1.1.7 and the beta variant B.1.351. Orally bioavailable and with a long history of safe human use, these cannabinoids, isolated or in hemp extracts, have the potential to prevent as well as treat infection by SARS-CoV-2.
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Antivirales/farmacología , Tratamiento Farmacológico de COVID-19 , Cannabinoides/farmacología , SARS-CoV-2/efectos de los fármacos , Internalización del Virus/efectos de los fármacos , Enzima Convertidora de Angiotensina 2/metabolismo , Animales , Antivirales/química , Antivirales/metabolismo , Benzoatos/farmacología , COVID-19/prevención & control , Cannabinoides/química , Cannabinoides/metabolismo , Chlorocebus aethiops , Humanos , Ligandos , Espectrometría de Masas , Modelos Moleculares , Unión Proteica , Glicoproteína de la Espiga del Coronavirus/metabolismo , Células VeroRESUMEN
SARS-CoV-2 and its variants continue to infect hundreds of thousands every day despite the rollout of effective vaccines. Therefore, it is essential to understand the levels of protection that these vaccines provide in the face of emerging variants. Here, we report two demographically balanced cohorts of BNT162b2 vaccine recipients and COVID-19 patients, from which we evaluate neutralizing antibody titers against SARS-CoV-2 as well as the B.1.1.7 (alpha) and B.1.351 (beta) variants. We show that both B.1.1.7 and B.1.351 are less well neutralized by serum from vaccinated individuals, and that B.1.351, but not B.1.1.7, is less well neutralized by convalescent serum. We also find that the levels of variant-specific anti-spike antibodies are proportional to neutralizing activities. Together, our results demonstrate the escape of the emerging SARS-CoV-2 variants from neutralization by serum antibodies, which may lead to reduced protection from re-infection or increased risk of vaccine breakthrough.
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Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Vacunas contra la COVID-19/inmunología , COVID-19/inmunología , SARS-CoV-2/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Vacuna BNT162 , COVID-19/sangre , COVID-19/prevención & control , COVID-19/virología , Vacunas contra la COVID-19/administración & dosificación , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Pruebas de Neutralización , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Vacunación , Adulto JovenRESUMEN
We tested human sera from large, demographically balanced cohorts of BNT162b2 vaccine recipients (n=51) and COVID-19 patients (n=44) for neutralizing antibodies against SARS-CoV-2 variants B.1.1.7 and B.1.351. Although the effect is more pronounced in the vaccine cohort, both B.1.1.7 and B.1.351 show significantly reduced levels of neutralization by vaccinated and convalescent sera. Age is negatively correlated with neutralization in vaccinee, and levels of variant-specific RBD antibodies are proportional to neutralizing activities.
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In the ongoing coronavirus disease 2019 (COVID-19) pandemic, there remain unanswered questions regarding the nature and significance of the humoral immune response toward other coronavirus infections. Here, we investigate the cross-reactivity of antibodies raised against the first severe acute respiratory syndrome coronavirus (SARS-CoV) for their reactivity toward SARS-CoV-2. We extensively characterize a selection of 10 antibodies covering all of the SARS-CoV structural proteins: spike, membrane, nucleocapsid, and envelope. Although nearly all of the examined SARS-CoV antibodies display some level of reactivity to SARS-CoV-2, we find only partial cross-neutralization for the spike antibodies. The implications of our work are two-fold. First, we establish a set of antibodies with known reactivity to both SARS-CoV and SARS-CoV-2, which will allow further study of both viruses. Second, we provide empirical evidence of the high propensity for antibody cross-reactivity between distinct strains of human coronaviruses, which is critical information for designing diagnostic and vaccine strategies for COVID-19.
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Anticuerpos Antivirales/inmunología , SARS-CoV-2/inmunología , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , COVID-19/inmunología , COVID-19/virología , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/virología , Reacciones Cruzadas/inmunología , Células HEK293 , Humanos , Inmunidad Humoral/inmunología , Pandemias , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/genética , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/genéticaRESUMEN
There is currently a lack of biological tools to study the replication cycle and pathogenesis of SARS-CoV-2, the etiological agent of COVID-19. Repurposing the existing tools, including antibodies of SARS-CoV, is an effective way to accelerate the development of therapeutics for COVID-19. Here, we extensively characterized antibodies of the SARS-CoV structural proteins for their cross-reactivity, experimental utility, and neutralization of SARS-CoV-2. We assessed a total of 10 antibodies (six for Spike, two for Membrane, and one for Nucleocapsid and Envelope viral protein). We evaluated the utility of these antibodies against SARS-CoV-2 in a variety of assays, including immunofluorescence, ELISA, biolayer interferometry, western blots, and micro-neutralization. Remarkably, a high proportion of the antibodies we tested showed cross-reactivity, indicating a potentially generalizable theme of cross-reactivity between SARS-CoV and SARS-CoV-2 antibodies. These antibodies should help facilitate further research into SARS-CoV-2 basic biology. Moreover, our study provides critical information about the propensity of SARS-CoV antibodies to cross-react with SARS-CoV-2 and highlights its relevance in defining the clinical significance of such antibodies to improve testing and guide the development of novel vaccines and therapeutics.
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Zika virus (ZIKV), an arbovirus of global concern, remodels intracellular membranes to form replication sites. How ZIKV dysregulates lipid networks to allow this, and consequences for disease, is poorly understood. Here, we perform comprehensive lipidomics to create a lipid network map during ZIKV infection. We find that ZIKV significantly alters host lipid composition, with the most striking changes seen within subclasses of sphingolipids. Ectopic expression of ZIKV NS4B protein results in similar changes, demonstrating a role for NS4B in modulating sphingolipid pathways. Disruption of sphingolipid biosynthesis in various cell types, including human neural progenitor cells, blocks ZIKV infection. Additionally, the sphingolipid ceramide redistributes to ZIKV replication sites, and increasing ceramide levels by multiple pathways sensitizes cells to ZIKV infection. Thus, we identify a sphingolipid metabolic network with a critical role in ZIKV replication and show that ceramide flux is a key mediator of ZIKV infection.
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Interacciones Huésped-Patógeno , Esfingolípidos/metabolismo , Proteínas no Estructurales Virales/metabolismo , Infección por el Virus Zika/patología , Virus Zika/patogenicidad , Animales , Línea Celular Tumoral , Chlorocebus aethiops , Células HEK293 , Humanos , Lipidómica , Ratones , Esfingolípidos/análisis , Células Vero , Replicación Viral , Virus Zika/metabolismo , Infección por el Virus Zika/virologíaRESUMEN
RNA virus genomes are efficient and compact carriers of biological information, encoding information required for replication both in their primary sequences and in higher-order RNA structures. However, the ubiquity of RNA elements with higher-order folds-in which helices pack together to form complex 3D structures-and the extent to which these elements affect viral fitness are largely unknown. Here we used single-molecule correlated chemical probing to define secondary and tertiary structures across the RNA genome of dengue virus serotype 2 (DENV2). Higher-order RNA structures are pervasive and involve more than one-third of nucleotides in the DENV2 genomic RNA. These 3D structures promote a compact overall architecture and contribute to viral fitness. Disrupting RNA regions with higher-order structures leads to stable, nonreverting mutants and could guide the development of vaccines based on attenuated RNA viruses. The existence of extensive regions of functional RNA elements with tertiary folds in viral RNAs, and likely many other messenger and noncoding RNAs, means that there are significant regions with pocket-containing surfaces that may serve as novel RNA-directed drug targets.