RESUMEN
The liver is the largest solid organ in the body, yet it remains incompletely characterized. Here we present a spatial proteogenomic atlas of the healthy and obese human and murine liver combining single-cell CITE-seq, single-nuclei sequencing, spatial transcriptomics, and spatial proteomics. By integrating these multi-omic datasets, we provide validated strategies to reliably discriminate and localize all hepatic cells, including a population of lipid-associated macrophages (LAMs) at the bile ducts. We then align this atlas across seven species, revealing the conserved program of bona fide Kupffer cells and LAMs. We also uncover the respective spatially resolved cellular niches of these macrophages and the microenvironmental circuits driving their unique transcriptomic identities. We demonstrate that LAMs are induced by local lipid exposure, leading to their induction in steatotic regions of the murine and human liver, while Kupffer cell development crucially depends on their cross-talk with hepatic stellate cells via the evolutionarily conserved ALK1-BMP9/10 axis.
Asunto(s)
Evolución Biológica , Hepatocitos/metabolismo , Macrófagos/metabolismo , Proteogenómica , Animales , Núcleo Celular/metabolismo , Hígado Graso/genética , Hígado Graso/patología , Homeostasis , Humanos , Macrófagos del Hígado/metabolismo , Antígenos Comunes de Leucocito/metabolismo , Lípidos/química , Hígado/metabolismo , Linfocitos/metabolismo , Ratones Endogámicos C57BL , Modelos Biológicos , Células Mieloides/metabolismo , Obesidad/patología , Proteoma/metabolismo , Transducción de Señal , Transcriptoma/genéticaRESUMEN
Dengue is a major health threat and the number of symptomatic infections caused by the four dengue serotypes is estimated to be 96 million1 with annually around 10,000 deaths2. However, no antiviral drugs are available for the treatment or prophylaxis of dengue. We recently described the interaction between non-structural proteins NS3 and NS4B as a promising target for the development of pan-serotype dengue virus (DENV) inhibitors3. Here we present JNJ-1802-a highly potent DENV inhibitor that blocks the NS3-NS4B interaction within the viral replication complex. JNJ-1802 exerts picomolar to low nanomolar in vitro antiviral activity, a high barrier to resistance and potent in vivo efficacy in mice against infection with any of the four DENV serotypes. Finally, we demonstrate that the small-molecule inhibitor JNJ-1802 is highly effective against viral infection with DENV-1 or DENV-2 in non-human primates. JNJ-1802 has successfully completed a phase I first-in-human clinical study in healthy volunteers and was found to be safe and well tolerated4. These findings support the further clinical development of JNJ-1802, a first-in-class antiviral agent against dengue, which is now progressing in clinical studies for the prevention and treatment of dengue.
Asunto(s)
Antivirales , Virus del Dengue , Dengue , Primates , Proteínas no Estructurales Virales , Animales , Humanos , Ratones , Antivirales/efectos adversos , Antivirales/farmacología , Antivirales/uso terapéutico , Ensayos Clínicos Fase I como Asunto , Dengue/tratamiento farmacológico , Dengue/prevención & control , Dengue/virología , Virus del Dengue/clasificación , Virus del Dengue/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Farmacorresistencia Viral , Técnicas In Vitro , Terapia Molecular Dirigida , Primates/virología , Unión Proteica/efectos de los fármacos , Proteínas no Estructurales Virales/antagonistas & inhibidores , Proteínas no Estructurales Virales/metabolismo , Replicación ViralRESUMEN
Dengue virus causes approximately 96 million symptomatic infections annually, manifesting as dengue fever or occasionally as severe dengue1,2. There are no antiviral agents available to prevent or treat dengue. Here, we describe a highly potent dengue virus inhibitor (JNJ-A07) that exerts nanomolar to picomolar activity against a panel of 21 clinical isolates that represent the natural genetic diversity of known genotypes and serotypes. The molecule has a high barrier to resistance and prevents the formation of the viral replication complex by blocking the interaction between two viral proteins (NS3 and NS4B), thus revealing a previously undescribed mechanism of antiviral action. JNJ-A07 has a favourable pharmacokinetic profile that results in outstanding efficacy against dengue virus infection in mouse infection models. Delaying start of treatment until peak viraemia results in a rapid and significant reduction in viral load. An analogue is currently in further development.
Asunto(s)
Antivirales/farmacología , Virus del Dengue/clasificación , Virus del Dengue/efectos de los fármacos , Dengue/virología , Proteínas de la Membrana/metabolismo , Proteínas no Estructurales Virales/metabolismo , Animales , Antivirales/farmacocinética , Antivirales/uso terapéutico , Dengue/tratamiento farmacológico , Virus del Dengue/genética , Virus del Dengue/metabolismo , Modelos Animales de Enfermedad , Femenino , Masculino , Proteínas de la Membrana/antagonistas & inhibidores , Ratones , ARN Helicasas/antagonistas & inhibidores , ARN Helicasas/metabolismo , Serina Endopeptidasas/metabolismo , Carga Viral/efectos de los fármacos , Proteínas no Estructurales Virales/antagonistas & inhibidores , Viremia/tratamiento farmacológico , Viremia/virología , Replicación Viral/efectos de los fármacosRESUMEN
The expanding pandemic of coronavirus disease 2019 (COVID-19) requires the development of safe, efficacious and fast-acting vaccines. Several vaccine platforms are being leveraged for a rapid emergency response1. Here we describe the development of a candidate vaccine (YF-S0) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that uses live-attenuated yellow fever 17D (YF17D) vaccine as a vector to express a noncleavable prefusion form of the SARS-CoV-2 spike antigen. We assess vaccine safety, immunogenicity and efficacy in several animal models. YF-S0 has an excellent safety profile and induces high levels of SARS-CoV-2 neutralizing antibodies in hamsters (Mesocricetus auratus), mice (Mus musculus) and cynomolgus macaques (Macaca fascicularis), and-concomitantly-protective immunity against yellow fever virus. Humoral immunity is complemented by a cellular immune response with favourable T helper 1 polarization, as profiled in mice. In a hamster model2 and in macaques, YF-S0 prevents infection with SARS-CoV-2. Moreover, a single dose conferred protection from lung disease in most of the vaccinated hamsters within as little as 10 days. Taken together, the quality of the immune responses triggered and the rapid kinetics by which protective immunity can be attained after a single dose warrant further development of this potent SARS-CoV-2 vaccine candidate.
Asunto(s)
Vacunas contra la COVID-19/inmunología , COVID-19/inmunología , COVID-19/prevención & control , Vectores Genéticos/genética , SARS-CoV-2/inmunología , Vacunas Atenuadas/inmunología , Vacuna contra la Fiebre Amarilla/genética , Animales , Vacunas contra la COVID-19/administración & dosificación , Vacunas contra la COVID-19/efectos adversos , Vacunas contra la COVID-19/genética , Cricetinae , Modelos Animales de Enfermedad , Femenino , Glicosilación , Macaca fascicularis/genética , Macaca fascicularis/inmunología , Macaca fascicularis/virología , Masculino , Mesocricetus/genética , Mesocricetus/inmunología , Mesocricetus/virología , Ratones , Seguridad , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/metabolismo , Vacunas Atenuadas/administración & dosificación , Vacunas Atenuadas/efectos adversos , Vacunas Atenuadas/genéticaRESUMEN
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the aetiological agent of coronavirus disease 2019 (COVID-19), an emerging respiratory infection caused by the introduction of a novel coronavirus into humans late in 2019 (first detected in Hubei province, China). As of 18 September 2020, SARS-CoV-2 has spread to 215 countries, has infected more than 30 million people and has caused more than 950,000 deaths. As humans do not have pre-existing immunity to SARS-CoV-2, there is an urgent need to develop therapeutic agents and vaccines to mitigate the current pandemic and to prevent the re-emergence of COVID-19. In February 2020, the World Health Organization (WHO) assembled an international panel to develop animal models for COVID-19 to accelerate the testing of vaccines and therapeutic agents. Here we summarize the findings to date and provides relevant information for preclinical testing of vaccine candidates and therapeutic agents for COVID-19.
Asunto(s)
Infecciones por Coronavirus/tratamiento farmacológico , Infecciones por Coronavirus/prevención & control , Modelos Animales de Enfermedad , Pandemias/prevención & control , Neumonía Viral/tratamiento farmacológico , Neumonía Viral/prevención & control , Animales , Betacoronavirus/efectos de los fármacos , Betacoronavirus/inmunología , COVID-19 , Vacunas contra la COVID-19 , Infecciones por Coronavirus/inmunología , Hurones/virología , Humanos , Mesocricetus/virología , Ratones , Neumonía Viral/inmunología , Primates/virología , SARS-CoV-2 , Vacunas Virales/inmunologíaRESUMEN
Ancestral severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lacks the intrinsic ability to bind to the mouse ACE2 receptor, and therefore establishment of SARS-CoV-2 mouse models has been limited to the use of mouse-adapted viruses or genetically modified mice. Interestingly, some of the variants of concern, such as the Beta B.1.351 variant, show an improved binding to the mouse receptor and hence better replication in different wild-type (WT) mouse species. Here, we describe the establishment of a SARS-CoV-2 Beta B.1.351 variant infection model in male SCID mice as a tool to assess the antiviral efficacy of potential SARS-CoV-2 small-molecule inhibitors. Intranasal infection of male SCID mice with 105 50% tissue culture infective doses (TCID50) of the Beta B.1.351 variant resulted in high viral loads in the lungs and moderate signs of lung pathology on day 3 postinfection. Treatment of infected mice with the antiviral drugs molnupiravir (200 mg/kg, twice a day [BID]) or nirmatrelvir (300 mg/kg, BID) for 3 consecutive days significantly reduced the infectious virus titers in the lungs by 2 and 3.9 log10 TCID50/mg of tissue, respectively, and significantly improved lung pathology. Together, these data demonstrate the validity of this SCID mouse Beta B.1.351 variant infection model as a convenient preclinical model for assessment of potential activity of antivirals against SARS-CoV-2. IMPORTANCE Unlike the ancestral SARS-CoV-2 strain, the Beta (B.1.351) variant of concern has been reported to replicate to some extent in WT mice (C57BL/6 and BALB/c). We demonstrate here that infection of SCID mice with the Beta variant resulted in high viral loads in the lungs on day 3 postinfection. Treatment of infected mice with molnupiravir or nirmatrelvir for 3 consecutive days markedly reduced the infectious virus titers in the lungs and improved lung pathology. The SARS-CoV2 SCID mouse infection model, which is ideally suited for antiviral studies, offers an advantage in comparison to other SARS-CoV2 mouse models, in that there is no need for the use of mouse-adapted virus strains or genetically modified mice. Mouse models also have advantages over hamster models because (i) lower amounts of test drugs are needed, (ii) more animals can be housed in a cage, and (iii) reagents to analyze mouse samples are more readily available than those for hamsters.
Asunto(s)
Tratamiento Farmacológico de COVID-19 , SARS-CoV-2 , Animales , Antivirales/farmacología , Antivirales/uso terapéutico , Cricetinae , Modelos Animales de Enfermedad , Humanos , Pulmón , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones SCID , ARN ViralRESUMEN
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly spread around the globe after its emergence in Wuhan in December 2019. With no specific therapeutic and prophylactic options available, the virus has infected millions of people of which more than half a million succumbed to the viral disease, COVID-19. The urgent need for an effective treatment together with a lack of small animal infection models has led to clinical trials using repurposed drugs without preclinical evidence of their in vivo efficacy. We established an infection model in Syrian hamsters to evaluate the efficacy of small molecules on both infection and transmission. Treatment of SARS-CoV-2-infected hamsters with a low dose of favipiravir or hydroxychloroquine with(out) azithromycin resulted in, respectively, a mild or no reduction in virus levels. However, high doses of favipiravir significantly reduced infectious virus titers in the lungs and markedly improved lung histopathology. Moreover, a high dose of favipiravir decreased virus transmission by direct contact, whereas hydroxychloroquine failed as prophylaxis. Pharmacokinetic modeling of hydroxychloroquine suggested that the total lung exposure to the drug did not cause the failure. Our data on hydroxychloroquine (together with previous reports in macaques and ferrets) thus provide no scientific basis for the use of this drug in COVID-19 patients. In contrast, the results with favipiravir demonstrate that an antiviral drug at nontoxic doses exhibits a marked protective effect against SARS-CoV-2 in a small animal model. Clinical studies are required to assess whether a similar antiviral effect is achievable in humans without toxic effects.
Asunto(s)
Amidas/uso terapéutico , Antivirales/uso terapéutico , Betacoronavirus/efectos de los fármacos , Hidroxicloroquina/uso terapéutico , Pirazinas/uso terapéutico , Amidas/farmacocinética , Animales , Chlorocebus aethiops , Infecciones por Coronavirus/tratamiento farmacológico , Infecciones por Coronavirus/virología , Cricetinae , Modelos Animales de Enfermedad , Transmisión de Enfermedad Infecciosa/prevención & control , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Femenino , Hidroxicloroquina/farmacocinética , Pulmón/efectos de los fármacos , Pulmón/patología , Pulmón/virología , Pirazinas/farmacocinética , SARS-CoV-2 , Resultado del Tratamiento , Células Vero , Carga Viral/efectos de los fármacos , Tratamiento Farmacológico de COVID-19RESUMEN
In humans, Zika virus and viral RNA have been detected in semen up to 2.2 months and 6 months post infection (pi), respectively. Although the contribution of sexual transmission to the spread of ZIKV is too low to sustain an outbreak, it can increase the risk of infection and the epidemic size as well as prolong the duration of an outbreak. In this study, we explored the potential of antivirals to serve as an effective strategy to prevent sexual transmission. Male AG129 mice infected with a ZIKV isolate from Suriname were treated with the nucleoside analog, 7-deaza-2'-C-methyladenosine (7DMA), that was previously shown to be efficacious in reducing ZIKV viremia and delaying ZIKV-induced disease in mice. Following treatment, viral RNA and infectious virus titers were consistently reduced in the male reproductive organs compared to vehicle-treated mice. This reduction of ZIKV loads in the testis was confirmed by the detection of lower levels of ZIKV antigens. Our data illustrate the value of this mouse model to validate the efficacy of new potential ZIKV drugs at the level of the male reproductive system.
Asunto(s)
Antivirales/farmacología , Inhibidores Enzimáticos/farmacología , Replicación Viral/efectos de los fármacos , Infección por el Virus Zika/virología , Virus Zika/efectos de los fármacos , Virus Zika/enzimología , Animales , Línea Celular , Modelos Animales de Enfermedad , Humanos , Masculino , Ratones , Carga Viral/efectos de los fármacos , Infección por el Virus Zika/tratamiento farmacológico , Infección por el Virus Zika/patologíaRESUMEN
Dengue fever represents a significant medical and socio-economic burden in (sub)tropical regions, yet antivirals for treatment or prophylaxis are lacking. JNJ-A07 was described as highly active against the different genotypes within each serotype of the disease-causing dengue virus (DENV). Based on clustering of resistance mutations it has been assumed to target DENV non-structural protein 4B (NS4B). Using a photoaffinity labeling compound with high structural similarity to JNJ-A07, here we demonstrate binding to NS4B and its precursor NS4A-2K-NS4B. Consistently, we report recruitment of the compound to intracellular sites enriched for these proteins. We further specify the mechanism-of-action of JNJ-A07, which has virtually no effect on viral polyprotein cleavage, but targets the interaction between the NS2B/NS3 protease/helicase complex and the NS4A-2K-NS4B cleavage intermediate. This interaction is functionally linked to de novo formation of vesicle packets (VPs), the sites of DENV RNA replication. JNJ-A07 blocks VPs biogenesis with little effect on established ones. A similar mechanism-of-action was found for another NS4B inhibitor, NITD-688. In summary, we unravel the antiviral mechanism of these NS4B-targeting molecules and show how DENV employs a short-lived cleavage intermediate to carry out an early step of the viral life cycle.
Asunto(s)
Antivirales , Virus del Dengue , Dengue , Proteínas no Estructurales Virales , Replicación Viral , Virus del Dengue/efectos de los fármacos , Virus del Dengue/genética , Virus del Dengue/fisiología , Proteínas no Estructurales Virales/metabolismo , Proteínas no Estructurales Virales/genética , Proteínas no Estructurales Virales/antagonistas & inhibidores , Replicación Viral/efectos de los fármacos , Antivirales/farmacología , Humanos , Dengue/virología , Dengue/tratamiento farmacológico , Serogrupo , ARN Helicasas/metabolismo , ARN Helicasas/antagonistas & inhibidores , ARN Helicasas/genética , Serina Endopeptidasas/metabolismo , Serina Endopeptidasas/genética , Unión Proteica , Animales , Orgánulos/metabolismo , Orgánulos/efectos de los fármacos , Proteasas Virales , Aminofenoles , Proteínas de la Membrana , Indoles , ARN Helicasas DEAD-box , Nucleósido-Trifosfatasa , ButiratosRESUMEN
To curb viral epidemics and pandemics, antiviral drugs are needed with activity against entire genera or families of viruses. Here, we develop a cell-based multiplex antiviral assay for high-throughput screening against multiple viruses at once, as demonstrated by using three distantly related orthoflaviviruses: dengue, Japanese encephalitis and yellow fever virus. Each virus is tagged with a distinct fluorescent protein, enabling individual monitoring in cell culture through high-content imaging. Specific antisera and small-molecule inhibitors are employed to validate that multiplexing approach yields comparable inhibition profiles to single-virus infection assays. To facilitate downstream analysis, a kernel is developed to deconvolute and reduce the multidimensional quantitative data to three cartesian coordinates. The methodology is applicable to viruses from different families as exemplified by co-infections with chikungunya, parainfluenza and Bunyamwera viruses. The multiplex approach is expected to facilitate the discovery of broader-spectrum antivirals, as shown in a pilot screen of approximately 1200 drug-like small-molecules.
Asunto(s)
Virosis , Virus , Humanos , Antivirales/farmacología , Ensayos Analíticos de Alto Rendimiento/métodos , Técnicas de Cultivo de Célula , Replicación ViralRESUMEN
Dengue is a global public health threat, with about half of the world's population at risk of contracting this mosquito-borne viral disease. Climate change, urbanization, and global travel accelerate the spread of dengue virus (DENV) to new areas, including southern parts of Europe and the US. Currently, no dengue-specific small-molecule antiviral for prophylaxis or treatment is available. Here, we report the discovery of JNJ-1802 as a potent, pan-serotype DENV inhibitor (EC50's ranging from 0.057 to 11 nM against the four DENV serotypes). The observed oral bioavailability of JNJ-1802 across preclinical species, its low clearance in human hepatocytes, the absence of major in vitro pharmacology safety alerts, and a dose-proportional increase in efficacy against DENV-2 infection in mice were all supportive of its selection as a development candidate against dengue. JNJ-1802 is being progressed in clinical studies for the prevention or treatment of dengue.
Asunto(s)
Virus del Dengue , Dengue , Hidrocarburos Halogenados , Indoles , Ratones , Humanos , Animales , Serogrupo , Dengue/tratamiento farmacológicoRESUMEN
The hepatitis E virus (HEV) is a major cause of hepatitis, with an estimated 3.3 million symptomatic cases annually. There is no HEV-specific treatment besides the off-label use of ribavirin and a vaccine is only available in China and Pakistan. To aid the development of therapeutic and preventive strategies, there is a need for convenient HEV infection models in small laboratory animals. To this end, we make use of the rat hepatitis E virus. Human infections with this virus have been reported in recent years, making it a relevant pathogen for the establishment of a small animal infection model. We here report that oral gavage of a feces suspension, containing a pre-defined viral RNA load, results in a reproducible synchronized infection in athymic nude rats. This route of administration mimics fecal-oral transmission in a standardized fashion. The suitability of the model to study the effect of antiviral drugs was assessed by using ribavirin, which significantly reduced viral loads in the feces, liver, and other tissues.
Asunto(s)
Virus de la Hepatitis E , Hepatitis E , Animales , Ratas , Humanos , Antivirales/farmacología , Antivirales/uso terapéutico , Ribavirina/farmacología , Ribavirina/uso terapéutico , Hepatitis E/tratamiento farmacológico , ARN Viral/genética , HecesRESUMEN
In the absence of any approved dengue-specific treatment, the discovery and development of a novel small-molecule antiviral for the prevention or treatment of dengue are critical. We previously reported the identification of a novel series of 3-acyl-indole derivatives as potent and pan-serotype dengue virus inhibitors. We herein describe our optimization efforts toward preclinical candidates 24a and 28a with improved pan-serotype coverage (EC50's against the four DENV serotypes ranging from 0.0011 to 0.24 µM for 24a and from 0.00060 to 0.084 µM for 28a), chiral stability, and oral bioavailability in preclinical species, as well as showing a dose-proportional increase in efficacy against DENV-2 infection in vivo in mice.
Asunto(s)
Virus del Dengue , Dengue , Ratones , Animales , Serogrupo , Antivirales/farmacología , Antivirales/uso terapéutico , Dengue/tratamiento farmacológico , Indoles/farmacología , Indoles/uso terapéuticoRESUMEN
Remdesivir (GS-5734; VEKLURY) is a single diastereomer monophosphoramidate prodrug of an adenosine analog (GS-441524). Remdesivir is taken up by target cells and metabolized in multiple steps to form the active nucleoside triphosphate (GS-443902), which acts as a potent inhibitor of viral RNA-dependent RNA polymerases. Remdesivir and GS-441524 have antiviral activity against multiple RNA viruses. Here, we expand the evaluation of remdesivir's antiviral activity to members of the families Flaviviridae, Picornaviridae, Filoviridae, Orthomyxoviridae, and Hepadnaviridae. Using cell-based assays, we show that remdesivir can inhibit infection of flaviviruses (such as dengue 1-4, West Nile, yellow fever, Zika viruses), picornaviruses (such as enterovirus and rhinovirus), and filoviruses (such as various Ebola, Marburg, and Sudan virus isolates, including novel geographic isolates), but is ineffective or is significantly less effective against orthomyxoviruses (influenza A and B viruses), or hepadnaviruses B, D, and E. In addition, remdesivir shows no antagonistic effect when combined with favipiravir, another broadly acting antiviral nucleoside analog, and has minimal interaction with a panel of concomitant medications. Our data further support remdesivir as a broad-spectrum antiviral agent that has the potential to address multiple unmet medical needs, including those related to antiviral pandemic preparedness.
Asunto(s)
Filoviridae , Fiebre Hemorrágica Ebola , Infección por el Virus Zika , Virus Zika , Humanos , Antivirales/farmacología , Antivirales/uso terapéutico , Adenosina Monofosfato , Alanina , Fiebre Hemorrágica Ebola/tratamiento farmacológico , Infección por el Virus Zika/tratamiento farmacológicoRESUMEN
Nelfinavir is an HIV protease inhibitor that has been widely prescribed as a component of highly active antiretroviral therapy, and has been reported to exert in vitro antiviral activity against SARS-CoV-2. We here assessed the effect of Nelfinavir in a SARS-CoV-2 infection model in hamsters. Despite the fact that Nelfinavir, [50 mg/kg twice daily (BID) for four consecutive days], did not reduce viral RNA load and infectious virus titres in the lung of infected animals, treatment resulted in a substantial improvement of SARS-CoV-2-induced lung pathology. This was accompanied by a dense infiltration of neutrophils in the lung interstitium which was similarly observed in non-infected hamsters. Nelfinavir resulted also in a marked increase in activated neutrophils in the blood, as observed in non-infected animals. Although Nelfinavir treatment did not alter the expression of chemoattractant receptors or adhesion molecules on human neutrophils, in vitro migration of human neutrophils to the major human neutrophil attractant CXCL8 was augmented by this protease inhibitor. Nelfinavir appears to induce an immunomodulatory effect associated with increasing neutrophil number and functionality, which may be linked to the marked improvement in SARS-CoV-2 lung pathology independent of its lack of antiviral activity. Since Nelfinavir is no longer used for the treatment of HIV, we studied the effect of two other HIV protease inhibitors, namely the combination Lopinavir/Ritonavir (Kaletra™) in this model. This combination resulted in a similar protective effect as Nelfinavir against SARS-CoV2 induced lung pathology in hamsters.
Asunto(s)
Tratamiento Farmacológico de COVID-19 , Infecciones por VIH , Inhibidores de la Proteasa del VIH , Animales , Cricetinae , Infecciones por VIH/tratamiento farmacológico , Inhibidores de la Proteasa del VIH/farmacología , Inhibidores de la Proteasa del VIH/uso terapéutico , Lopinavir/farmacología , Lopinavir/uso terapéutico , Pulmón , Mesocricetus , Nelfinavir/farmacología , Nelfinavir/uso terapéutico , ARN Viral , Ritonavir/uso terapéutico , SARS-CoV-2RESUMEN
BACKGROUND: Within one year after its emergence, more than 108 million people acquired SARS-CoV-2 and almost 2·4 million succumbed to COVID-19. New SARS-CoV-2 variants of concern (VoC) are emerging all over the world, with the threat of being more readily transmitted, being more virulent, or escaping naturally acquired and vaccine-induced immunity. At least three major prototypic VoC have been identified, i.e. the United Kingdom, UK (B.1.1.7), South African (B.1.351) and Brazilian (B.1.1.28.1) variants. These are replacing formerly dominant strains and sparking new COVID-19 epidemics. METHODS: We studied the effect of infection with prototypic VoC from both B.1.1.7 and B.1.351 variants in female Syrian golden hamsters to assess their relative infectivity and virulence in direct comparison to two basal SARS-CoV-2 strains isolated in early 2020. FINDINGS: A very efficient infection of the lower respiratory tract of hamsters by these VoC is observed. In line with clinical evidence from patients infected with these VoC, no major differences in disease outcome were observed as compared to the original strains as was quantified by (i) histological scoring, (ii) micro-computed tomography, and (iii) analysis of the expression profiles of selected antiviral and pro-inflammatory cytokine genes. Noteworthy however, in hamsters infected with VoC B.1.1.7, a particularly strong elevation of proinflammatory cytokines was detected. INTERPRETATION: We established relevant preclinical infection models that will be pivotal to assess the efficacy of current and future vaccine(s) (candidates) as well as therapeutics (small molecules and antibodies) against two important SARS-CoV-2 VoC. FUNDING: Stated in the acknowledgment.
Asunto(s)
COVID-19/patología , Citocinas/genética , Sistema Respiratorio/virología , SARS-CoV-2/patogenicidad , Animales , COVID-19/diagnóstico por imagen , COVID-19/genética , Modelos Animales de Enfermedad , Evolución Molecular , Femenino , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Mesocricetus , Sistema Respiratorio/diagnóstico por imagen , Sistema Respiratorio/patología , SARS-CoV-2/clasificación , SARS-CoV-2/inmunología , Virulencia , Microtomografía por Rayos XRESUMEN
BACKGROUND: Favipiravir and Molnupiravir, orally available antivirals, have been reported to exert antiviral activity against SARS-CoV-2. First efficacy data have been recently reported in COVID-19 patients. METHODS: We here report on the combined antiviral effect of both drugs in a SARS-CoV-2 Syrian hamster infection model. The infected hamsters were treated twice daily with the vehicle (the control group) or a suboptimal dose of each compound or a combination of both compounds. FINDINGS: When animals were treated with a combination of suboptimal doses of Molnupiravir and Favipiravir at the time of infection, a marked combined potency at endpoint is observed. Infectious virus titers in the lungs of animals treated with the combination are reduced by â¼5 log10 and infectious virus are no longer detected in the lungs of >60% of treated animals. When start of treatment was delayed with one day a reduction of titers in the lungs of 2.4 log10 was achieved. Moreover, treatment of infected animals nearly completely prevented transmission to co-housed untreated sentinels. Both drugs result in an increased mutation frequency of the remaining viral RNA recovered from the lungs of treated animals. In the combo-treated hamsters, an increased frequency of C-to-T mutations in the viral RNA is observed as compared to the single treatment groups which may explain the pronounced antiviral potency of the combination. INTERPRETATION: Our findings may lay the basis for the design of clinical studies to test the efficacy of the combination of Molnupiravir/Favipiravir in the treatment of COVID-19. FUNDING: stated in the acknowledgment.
Asunto(s)
Amidas/uso terapéutico , Tratamiento Farmacológico de COVID-19 , Citidina/análogos & derivados , Hidroxilaminas/uso terapéutico , Pulmón/virología , Pirazinas/uso terapéutico , Amidas/farmacología , Animales , Antivirales/farmacología , Antivirales/uso terapéutico , COVID-19/transmisión , Citidina/farmacología , Citidina/uso terapéutico , Modelos Animales de Enfermedad , Quimioterapia Combinada , Femenino , Hidroxilaminas/farmacología , Mesocricetus , Pirazinas/farmacología , ARN Viral , Resultado del Tratamiento , Carga ViralRESUMEN
The global emergence of Zika virus (ZIKV) revealed the unprecedented ability for a mosquito-borne virus to cause congenital birth defects. A puzzling aspect of ZIKV emergence is that all human outbreaks and birth defects to date have been exclusively associated with the Asian ZIKV lineage, despite a growing body of laboratory evidence pointing towards higher transmissibility and pathogenicity of the African ZIKV lineage. Whether this apparent paradox reflects the use of relatively old African ZIKV strains in most laboratory studies is unclear. Here, we experimentally compare seven low-passage ZIKV strains representing the recently circulating viral genetic diversity. We find that recent African ZIKV strains display higher transmissibility in mosquitoes and higher lethality in both adult and fetal mice than their Asian counterparts. We emphasize the high epidemic potential of African ZIKV strains and suggest that they could more easily go unnoticed by public health surveillance systems than Asian strains due to their propensity to cause fetal loss rather than birth defects.
Asunto(s)
Infección por el Virus Zika/mortalidad , Infección por el Virus Zika/virología , Virus Zika/fisiología , Virus Zika/patogenicidad , Aedes/fisiología , Aedes/virología , África , Animales , Asia , Femenino , Humanos , Masculino , Ratones , Filogenia , Virulencia , Virus Zika/clasificación , Virus Zika/genética , Infección por el Virus Zika/transmisiónRESUMEN
Broadly neutralizing antibodies are an important treatment for individuals with coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Antibody-based therapeutics are also essential for pandemic preparedness against future Sarbecovirus outbreaks. Camelid-derived single domain antibodies (VHHs) exhibit potent antimicrobial activity and are being developed as SARS-CoV-2neutralizing antibody-like therapeutics. Here, we identified VHHs that neutralize both SARS-CoV-1 and SARS-CoV-2, including now circulating variants. We observed that the VHHs bound to a highly conserved epitope in the receptor binding domain of the viral spike protein that is difficult to access for human antibodies. Structure-guided molecular modeling, combined with rapid yeast-based prototyping, resulted in an affinity enhanced VHH-human immunoglobulin G1 Fc fusion molecule with subnanomolar neutralizing activity. This VHH-Fc fusion protein, produced in and purified from cultured Chinese hamster ovary cells, controlled SARS-CoV-2 replication in prophylactic and therapeutic settings in mice expressing human angiotensin converting enzyme 2 and in hamsters infected with SARS-CoV-2. These data led to affinity-enhanced selection of the VHH, XVR011, a stable antiCOVID-19 biologic that is now being evaluated in the clinic.