Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 41
Filter
1.
Signal Transduct Target Ther ; 6(1): 438, 2021 12 24.
Article in English | MEDLINE | ID: covidwho-1585880

ABSTRACT

Messenger RNA (mRNA) vaccine technology has shown its power in preventing the ongoing COVID-19 pandemic. Two mRNA vaccines targeting the full-length S protein of SARS-CoV-2 have been authorized for emergency use. Recently, we have developed a lipid nanoparticle-encapsulated mRNA (mRNA-LNP) encoding the receptor-binding domain (RBD) of SARS-CoV-2 (termed ARCoV), which confers complete protection in mouse model. Herein, we further characterized the protection efficacy of ARCoV in nonhuman primates and the long-term stability under normal refrigerator temperature. Intramuscular immunization of two doses of ARCoV elicited robust neutralizing antibodies as well as cellular response against SARS-CoV-2 in cynomolgus macaques. More importantly, ARCoV vaccination in macaques significantly protected animals from acute lung lesions caused by SARS-CoV-2, and viral replication in lungs and secretion in nasal swabs were completely cleared in all animals immunized with low or high doses of ARCoV. No evidence of antibody-dependent enhancement of infection was observed throughout the study. Finally, extensive stability assays showed that ARCoV can be stored at 2-8 °C for at least 6 months without decrease of immunogenicity. All these promising results strongly support the ongoing clinical trial.


Subject(s)
COVID-19 Vaccines/pharmacology , COVID-19/immunology , Immunogenicity, Vaccine , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , /pharmacology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/prevention & control , COVID-19 Vaccines/immunology , Chlorocebus aethiops , Humans , Macaca fascicularis , Vero Cells , /immunology
2.
Nat Commun ; 12(1): 6097, 2021 10 20.
Article in English | MEDLINE | ID: covidwho-1475295

ABSTRACT

Effective treatments against Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) are urgently needed. Monoclonal antibodies have shown promising results in patients. Here, we evaluate the in vivo prophylactic and therapeutic effect of COVA1-18, a neutralizing antibody highly potent against the B.1.1.7 isolate. In both prophylactic and therapeutic settings, SARS-CoV-2 remains undetectable in the lungs of treated hACE2 mice. Therapeutic treatment also causes a reduction in viral loads in the lungs of Syrian hamsters. When administered at 10 mg kg-1 one day prior to a high dose SARS-CoV-2 challenge in cynomolgus macaques, COVA1-18 shows very strong antiviral activity in the upper respiratory compartments. Using a mathematical model, we estimate that COVA1-18 reduces viral infectivity by more than 95% in these compartments, preventing lymphopenia and extensive lung lesions. Our findings demonstrate that COVA1-18 has a strong antiviral activity in three preclinical models and could be a valuable candidate for further clinical evaluation.


Subject(s)
Antibodies, Monoclonal/administration & dosage , Antibodies, Neutralizing/administration & dosage , Antiviral Agents/administration & dosage , COVID-19/drug therapy , SARS-CoV-2/immunology , Angiotensin-Converting Enzyme 2/genetics , Animals , Antibodies, Monoclonal/pharmacokinetics , Antiviral Agents/pharmacokinetics , COVID-19/blood , COVID-19/immunology , COVID-19/virology , Disease Models, Animal , Drug Evaluation, Preclinical , Female , Humans , Lung/metabolism , Lung/virology , Macaca fascicularis , Male , Mesocricetus , Mice , Mice, Transgenic , SARS-CoV-2/isolation & purification , Tissue Distribution , Viral Load
3.
Proc Natl Acad Sci U S A ; 118(43)2021 10 26.
Article in English | MEDLINE | ID: covidwho-1462067

ABSTRACT

The pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a global threat to human health and life. A useful pathological animal model accurately reflecting human pathology is needed to overcome the COVID-19 crisis. In the present study, COVID-19 cynomolgus monkey models including monkeys with underlying diseases causing severe pathogenicity such as metabolic disease and elderly monkeys were examined. Cynomolgus macaques with various clinical conditions were intranasally and/or intratracheally inoculated with SARS-CoV-2. Infection with SARS-CoV-2 was found in mucosal swab samples, and a higher level and longer period of viral RNA was detected in elderly monkeys than in young monkeys. Pneumonia was confirmed in all of the monkeys by computed tomography images. When monkeys were readministrated SARS-CoV-2 at 56 d or later after initial infection all of the animals showed inflammatory responses without virus detection in swab samples. Surprisingly, in elderly monkeys reinfection showed transient severe pneumonia with increased levels of various serum cytokines and chemokines compared with those in primary infection. The results of this study indicated that the COVID-19 cynomolgus monkey model reflects the pathophysiology of humans and would be useful for elucidating the pathophysiology and developing therapeutic agents and vaccines.


Subject(s)
COVID-19/immunology , Disease Models, Animal , Macaca fascicularis/immunology , Primate Diseases/immunology , SARS-CoV-2/immunology , Animals , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/virology , Female , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Lung/diagnostic imaging , Lung/immunology , Lung/virology , Macaca fascicularis/virology , Male , Primate Diseases/virology , SARS-CoV-2/physiology , Tomography, X-Ray Computed/methods , Virus Shedding/immunology , Virus Shedding/physiology
4.
Comp Med ; 71(5): 433-441, 2021 10 01.
Article in English | MEDLINE | ID: covidwho-1444659

ABSTRACT

Animal models are at the forefront of biomedical research for studies of viral transmission, vaccines, and pathogenesis, yet the need for an ideal large animal model for COVID-19 remains. We used a meta-analysis to evaluate published data relevant to this need. Our literature survey contained 22 studies with data relevant to the incidence of common COVID-19 symptoms in rhesus macaques (Macaca mulatta), cynomolgus macaques (Macaca fascicularis), African green monkeys (Chlorocebus aethiops), and ferrets (Mustela putorius furo). Rhesus macaques had leukocytosis on Day 1 after inoculation and pneumonia on Days 7 and 14 after inoculation, in frequencies that were similar enough to humans to reject the null hypothesis of a Fisher exact test. However, the differences in overall presentation of disease were too different from that of humans to successfully identify any of these 4 species as an ideal large animal of COVID-19. The greatest limitation to the current study is a lack of standardization in experimentation and reporting. To expand our understanding of the pathology of COVID-19 and evalu- ate vaccine immunogenicity, we must extend the unprecedented collaboration that has arisen in the study of COVID-19 to include standardization of animal-based research in an effort to find the optimal animal model.


Subject(s)
COVID-19 , Ferrets , Animals , Chlorocebus aethiops , Disease Models, Animal , Humans , Macaca fascicularis , Macaca mulatta , SARS-CoV-2
5.
PLoS Pathog ; 17(8): e1009865, 2021 08.
Article in English | MEDLINE | ID: covidwho-1443861

ABSTRACT

While evidence exists supporting the potential for aerosol transmission of SARS-CoV-2, the infectious dose by inhalation remains unknown. In the present study, the probability of infection following inhalation of SARS-CoV-2 was dose-dependent in a nonhuman primate model of inhalational COVID-19. The median infectious dose, assessed by seroconversion, was 52 TCID50 (95% CI: 23-363 TCID50), and was significantly lower than the median dose for fever (256 TCID50, 95% CI: 102-603 TCID50), resulting in a group of animals that developed an immune response post-exposure but did not develop fever or other clinical signs of infection. In a subset of these animals, virus was detected in nasopharyngeal and/or oropharyngeal swabs, suggesting that infected animals without signs of disease are able to shed virus and may be infectious, which is consistent with reports of asymptomatic spread in human cases of COVID-19. These results suggest that differences in exposure dose may be a factor influencing disease presentation in humans, and reinforce the importance of public health measures that limit exposure dose, such as social distancing, masking, and increased ventilation. The dose-response data provided by this study are important to inform disease transmission and hazard modeling, and, ultimately, mitigation strategies. Additionally, these data will be useful to inform dose selection in future studies examining the efficacy of therapeutics and vaccines against inhalational COVID-19, and as a baseline in healthy, young adult animals for assessment of the importance of other factors, such as age, comorbidities, and viral variant, on the infectious dose and disease presentation.


Subject(s)
COVID-19/transmission , COVID-19/virology , Macaca fascicularis , Seroconversion , Animals , Chlorocebus aethiops , Disease Models, Animal , Female , Fever/virology , Inhalation Exposure , Male , Vero Cells , Viral Load
6.
PLoS Pathog ; 17(7): e1009668, 2021 07.
Article in English | MEDLINE | ID: covidwho-1388961

ABSTRACT

SARS-CoV-2 infection presents clinical manifestations ranging from asymptomatic to fatal respiratory failure. Despite the induction of functional SARS-CoV-2-specific CD8+ T-cell responses in convalescent individuals, the role of virus-specific CD8+ T-cell responses in the control of SARS-CoV-2 replication remains unknown. In the present study, we show that subacute SARS-CoV-2 replication can be controlled in the absence of CD8+ T cells in cynomolgus macaques. Eight macaques were intranasally inoculated with 105 or 106 TCID50 of SARS-CoV-2, and three of the eight macaques were treated with a monoclonal anti-CD8 antibody on days 5 and 7 post-infection. In these three macaques, CD8+ T cells were undetectable on day 7 and thereafter, while virus-specific CD8+ T-cell responses were induced in the remaining five untreated animals. Viral RNA was detected in nasopharyngeal swabs for 10-17 days post-infection in all macaques, and the kinetics of viral RNA levels in pharyngeal swabs and plasma neutralizing antibody titers were comparable between the anti-CD8 antibody treated and untreated animals. SARS-CoV-2 RNA was detected in the pharyngeal mucosa and/or retropharyngeal lymph node obtained at necropsy on day 21 in two of the untreated group but undetectable in all macaques treated with anti-CD8 antibody. CD8+ T-cell responses may contribute to viral control in SARS-CoV-2 infection, but our results indicate possible containment of subacute viral replication in the absence of CD8+ T cells, implying that CD8+ T-cell dysfunction may not solely lead to viral control failure.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , COVID-19/veterinary , Macaca fascicularis/immunology , Macaca fascicularis/virology , Monkey Diseases/immunology , Monkey Diseases/virology , SARS-CoV-2/immunology , SARS-CoV-2/physiology , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/immunology , COVID-19/virology , Disease Models, Animal , Female , Humans , Kinetics , Lymphocyte Depletion/veterinary , Male , RNA, Viral/genetics , RNA, Viral/metabolism , SARS-CoV-2/genetics , Virus Replication/immunology
7.
Front Immunol ; 12: 645210, 2021.
Article in English | MEDLINE | ID: covidwho-1383856

ABSTRACT

Vaccination is one of the most efficient public healthcare measures to fight infectious diseases. Nevertheless, the immune mechanisms induced in vivo by vaccination are still unclear. The route of administration, an important vaccination parameter, can substantially modify the quality of the response. How the route of administration affects the generation and profile of immune responses is of major interest. Here, we aimed to extensively characterize the profiles of the innate and adaptive response to vaccination induced after intradermal, subcutaneous, or intramuscular administration with a modified vaccinia virus Ankara model vaccine in non-human primates. The adaptive response following subcutaneous immunization was clearly different from that following intradermal or intramuscular immunization. The subcutaneous route induced a higher level of neutralizing antibodies than the intradermal and intramuscular vaccination routes. In contrast, polyfunctional CD8+ T-cell responses were preferentially induced after intradermal or intramuscular injection. We observed the same dichotomy when analyzing the early molecular and cellular immune events, highlighting the recruitment of cell populations, such as CD8+ T lymphocytes and myeloid-derived suppressive cells, and the activation of key immunomodulatory gene pathways. These results demonstrate that the quality of the vaccine response induced by an attenuated vaccine is shaped by early and subtle modifications of the innate immune response. In this immunization context, the route of administration must be tailored to the desired type of protective immune response. This will be achieved through systems vaccinology and mathematical modeling, which will be critical for predicting the efficacy of the vaccination route for personalized medicine.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , CD8-Positive T-Lymphocytes/immunology , Myeloid-Derived Suppressor Cells/immunology , Vaccination , Vaccinia virus/immunology , Vaccinia/immunology , Viral Vaccines/pharmacology , Animals , Injections, Intradermal , Injections, Intramuscular , Macaca fascicularis , Male , Vaccines, Attenuated/pharmacology
8.
Viruses ; 13(8)2021 08 23.
Article in English | MEDLINE | ID: covidwho-1367929

ABSTRACT

The post-acute phase of SARS-CoV-2 infection was investigated in rhesus (Macaca mulatta) and cynomolgus macaques (Macaca fascicularis). During the acute phase of infection, SARS-CoV-2 was shed via the nose and throat, and viral RNA was occasionally detected in feces. This phase coincided with a transient change in systemic immune activation. Even after the alleged resolution of the infection, computed tomography (CT) and positron emission tomography (PET)-CT revealed pulmonary lesions and activated tracheobronchial lymph nodes in all animals. Post-mortem histological examination of the lung tissue revealed mostly marginal or resolving minimal lesions that were indicative of SARS-CoV-2 infection. Evidence for SARS-CoV-2-induced histopathology was also found in extrapulmonary tissue samples, such as conjunctiva, cervical, and mesenteric lymph nodes. However, 5-6 weeks after SARS-CoV-2 exposure, upon necropsy, viral RNA was still detectable in a wide range of tissue samples in 50% of the macaques and included amongst others the heart, the respiratory tract and surrounding lymph nodes, salivary gland, and conjunctiva. Subgenomic messenger RNA was detected in the lungs and tracheobronchial lymph nodes, indicative of ongoing virus replication during the post-acute phase. These results could be relevant for understanding the long-term consequences of COVID-19 in humans.


Subject(s)
COVID-19/pathology , COVID-19/virology , Lung/pathology , SARS-CoV-2/physiology , Animals , Antibodies, Viral/blood , COVID-19/immunology , Cytokines/blood , Disease Models, Animal , Humans , Lung/virology , Lymph Nodes/pathology , Lymph Nodes/physiopathology , Macaca fascicularis , Macaca mulatta , RNA, Messenger/analysis , RNA, Viral/analysis , Respiratory System/pathology , Respiratory System/virology , SARS-CoV-2/immunology , Virus Replication
9.
Nat Commun ; 12(1): 5000, 2021 08 17.
Article in English | MEDLINE | ID: covidwho-1361637

ABSTRACT

The successive emergences and accelerating spread of novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lineages and evolved resistance to some ongoing clinical therapeutics increase the risks associated with the coronavirus disease 2019 (COVID-19) pandemic. An urgent intervention for broadly effective therapies to limit the morbidity and mortality of COVID-19 and future transmission events from SARS-related coronaviruses (SARSr-CoVs) is needed. Here, we isolate and humanize an angiotensin-converting enzyme-2 (ACE2)-blocking monoclonal antibody (MAb), named h11B11, which exhibits potent inhibitory activity against SARS-CoV and circulating global SARS-CoV-2 lineages. When administered therapeutically or prophylactically in the hACE2 mouse model, h11B11 alleviates and prevents SARS-CoV-2 replication and virus-induced pathological syndromes. No significant changes in blood pressure and hematology chemistry toxicology were observed after injections of multiple high dosages of h11B11 in cynomolgus monkeys. Analysis of the structures of the h11B11/ACE2 and receptor-binding domain (RBD)/ACE2 complexes shows hindrance and epitope competition of the MAb and RBD for the receptor. Together, these results suggest h11B11 as a potential therapeutic countermeasure against SARS-CoV, SARS-CoV-2, and escape variants.


Subject(s)
Angiotensin-Converting Enzyme 2/drug effects , Angiotensin-Converting Enzyme 2/immunology , Antibodies, Neutralizing/administration & dosage , COVID-19/drug therapy , SARS-CoV-2/drug effects , Animals , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , COVID-19/immunology , COVID-19/mortality , COVID-19/virology , Chlorocebus aethiops , Disease Models, Animal , Epitopes , Female , HEK293 Cells , Haplorhini , Humans , Macaca fascicularis , Male , Mice , Mice, Inbred BALB C , Pandemics , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , Vero Cells , Virus Activation
10.
Cell Host Microbe ; 29(9): 1437-1453.e8, 2021 09 08.
Article in English | MEDLINE | ID: covidwho-1347535

ABSTRACT

The SARS-CoV-2 pandemic has affected more than 185 million people worldwide resulting in over 4 million deaths. To contain the pandemic, there is a continued need for safe vaccines that provide durable protection at low and scalable doses and can be deployed easily. Here, AAVCOVID-1, an adeno-associated viral (AAV), spike-gene-based vaccine candidate demonstrates potent immunogenicity in mouse and non-human primates following a single injection and confers complete protection from SARS-CoV-2 challenge in macaques. Peak neutralizing antibody titers are sustained at 1 year and complemented by functional memory T cell responses. The AAVCOVID vector has no relevant pre-existing immunity in humans and does not elicit cross-reactivity to common AAVs used in gene therapy. Vector genome persistence and expression wanes following injection. The single low-dose requirement, high-yield manufacturability, and 1-month stability for storage at room temperature may make this technology well suited to support effective immunization campaigns for emerging pathogens on a global scale.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19 Vaccines/immunology , COVID-19/prevention & control , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/genetics , Dependovirus/genetics , Dependovirus/metabolism , Female , Humans , Immunogenicity, Vaccine/immunology , Immunologic Memory/immunology , Macaca fascicularis , Macaca mulatta , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , T-Lymphocytes/immunology , Transgenes/genetics , Vaccination/methods , Viral Load/immunology
11.
Drug Test Anal ; 13(10): 1727-1734, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1293157

ABSTRACT

BACKGROUND: Currently, severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) has spread worldwide as a severe pandemic and effective therapeutic medications are urgently needed. As reported previously, BD-604 is a fully human monoclonal antibody with strong in vitro and in vivo neutralizing activity to SARS-COV-2. OBJECTIVE: The purpose of this study was to characterize the pharmacokinetic propertie of BD-604 in cynomolgus monkeys. METHODS: To analyze the concentration of BD-604 in cynomolgus monkey serum, an ELISA assay was established, and a systemic validation was performed including accuracy and precision, dilution linearity and hook effect, selectivity, specificity, stability, and parallelism tests. Then, six naïve cynomolgus monkeys (3/sex) were administered BD-604 at a single dose of 10 mg/kg via intravenous infusion (60 min). Blood samples were collected at various time points (0-672 h) and analyzed for serum concentrations of BD-604. RESULTS: The data from validation experiments assure the reproducibility and reliability of the established ELISA assay. Then, the validated method was used to measure BD-604 concentration in cynomolgus monkey serum. The pharmacokinetics parameters including terminal half-life (t1/2 ), peak serum concentration (Cmax ), area under curve from time zero to last timepoint or infinity (AUClast /AUCinf ), apparent volume of distribution (Vz ), clearance rate (CL), and mean residence time (MRT) were calculated and reported. BD-604 showed no marked sex differences at the dose of 10 mg/kg when comparing the AUC0-last and Cmax between female and male cynomolgus monkeys. CONCLUSION: In cynomolgus monkeys, BD-604 possesses pharmacokinetic properties similar to natural IgGs.


Subject(s)
Antibodies, Monoclonal/blood , Antibodies, Neutralizing/blood , SARS-CoV-2/metabolism , Animals , Antibodies, Monoclonal/administration & dosage , Antibodies, Neutralizing/administration & dosage , CHO Cells , COVID-19 , Cricetinae , Cricetulus , Dose-Response Relationship, Drug , Female , Humans , Infusions, Intravenous , Macaca fascicularis , Male , SARS-CoV-2/drug effects
12.
Emerg Infect Dis ; 27(7): 1979-1981, 2021 07.
Article in English | MEDLINE | ID: covidwho-1278356

ABSTRACT

We analyzed size of severe acute respiratory coronavirus 2 (SARS-CoV-2) aerosol particles shed by experimentally infected cynomolgus monkeys. Most exhaled particles were small, and virus was mainly released early during infection. By postinfection day 6, no virus was detected in breath, but air in the isolator contained large quantities of aerosolized virus.


Subject(s)
COVID-19 , Middle East Respiratory Syndrome Coronavirus , Aerosols , Animals , Humans , Macaca fascicularis , SARS-CoV-2
13.
Nat Nanotechnol ; 16(8): 942-951, 2021 08.
Article in English | MEDLINE | ID: covidwho-1275929

ABSTRACT

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has grown into a global pandemic, and only a few antiviral treatments have been approved to date. Angiotensin-converting enzyme 2 (ACE2) plays a fundamental role in SARS-CoV-2 pathogenesis because it allows viral entry into host cells. Here we show that ACE2 nanodecoys derived from human lung spheroid cells (LSCs) can bind and neutralize SARS-CoV-2 and protect the host lung cells from infection. In mice, these LSC-nanodecoys were delivered via inhalation therapy and resided in the lungs for over 72 h post-delivery. Furthermore, inhalation of the LSC-nanodecoys accelerated clearance of SARS-CoV-2 mimics from the lungs, with no observed toxicity. In cynomolgus macaques challenged with live SARS-CoV-2, four doses of these nanodecoys delivered by inhalation promoted viral clearance and reduced lung injury. Our results suggest that LSC-nanodecoys can serve as a potential therapeutic agent for treating COVID-19.


Subject(s)
COVID-19/drug therapy , Lung Injury/prevention & control , Nanostructures/administration & dosage , SARS-CoV-2/drug effects , Administration, Inhalation , Angiotensin-Converting Enzyme 2/metabolism , Animals , COVID-19/virology , Cell-Derived Microparticles/metabolism , Cell-Derived Microparticles/transplantation , Disease Models, Animal , Humans , Lung Injury/virology , Macaca fascicularis , Mice , Protein Binding , SARS-CoV-2/metabolism , Spheroids, Cellular/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Viral Load/drug effects
14.
Emerg Microbes Infect ; 10(1): 1320-1330, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1266083

ABSTRACT

Ebola virus (EBOV) is a negative single-stranded RNA virus within the Filoviridae family and the causative agent of Ebola virus disease (EVD). Nonhuman primates (NHPs), including cynomolgus and rhesus macaques, are considered the gold standard animal model to interrogate mechanisms of EBOV pathogenesis. However, despite significant genetic similarity (>90%), NHP species display different clinical presentation following EBOV infection, notably a ∼1-2 days delay in disease progression. Consequently, evaluation of therapeutics is generally conducted in rhesus macaques, whereas cynomolgus macaques are utilized to determine efficacy of preventative treatments, notably vaccines. This observation is in line with reported differences in disease severity and host responses between these two NHP following infection with simian varicella virus, influenza A and SARS-CoV-2. However, the molecular underpinnings of these differential outcomes following viral infections remain poorly defined. In this study, we compared published transcriptional profiles obtained from cynomolgus and rhesus macaques infected with the EBOV-Makona Guinea C07 using bivariate and regression analyses to elucidate differences in host responses. We report the presence of a shared core of differentially expressed genes (DEGs) reflecting EVD pathology, including aberrant inflammation, lymphopenia, and coagulopathy. However, the magnitudes of change differed between the two macaque species. These findings suggest that the differential clinical presentation of EVD in these two species is mediated by altered transcriptional responses.


Subject(s)
Gene Expression Regulation/immunology , Hemorrhagic Fever, Ebola/veterinary , Macaca fascicularis , Macaca mulatta , Monkey Diseases/immunology , Transcription, Genetic/immunology , Animals , COVID-19 , Ebolavirus , Hemorrhagic Fever, Ebola/genetics , Hemorrhagic Fever, Ebola/immunology , Hemorrhagic Fever, Ebola/mortality , Humans , Immunity , Monkey Diseases/genetics , Monkey Diseases/mortality , RNA, Viral/metabolism , SARS-CoV-2 , Species Specificity
15.
Sci Adv ; 7(22)2021 05.
Article in English | MEDLINE | ID: covidwho-1247308

ABSTRACT

Since the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), various vaccines are being developed, with most vaccine candidates focusing on the viral spike protein. Here, we developed a previously unknown subunit vaccine comprising the receptor binding domain (RBD) of the spike protein fused with the tetanus toxoid epitope P2 (RBD-P2) and tested its efficacy in rodents and nonhuman primates (NHPs). We also investigated whether the SARS-CoV-2 nucleocapsid protein (N) could increase vaccine efficacy. Immunization with N and RBD-P2 (RBDP2/N) + alum increased T cell responses in mice and neutralizing antibody levels in rats compared with those obtained using RBD-P2 + alum. Furthermore, in NHPs, RBD-P2/N + alum induced slightly faster SARS-CoV-2 clearance than that induced by RBD-P2 + alum, albeit without statistical significance. Our study supports further development of RBD-P2 as a vaccine candidate against SARS-CoV-2. Also, it provides insights regarding the use of N in protein-based vaccines against SARS-CoV-2.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/prevention & control , Coronavirus Nucleocapsid Proteins/immunology , Recombinant Fusion Proteins/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Tetanus Toxoid/immunology , Animals , COVID-19/genetics , COVID-19/immunology , COVID-19 Vaccines/genetics , Chlorocebus aethiops , Coronavirus Nucleocapsid Proteins/genetics , Female , Macaca fascicularis , Mice , Mice, Inbred BALB C , Mice, Transgenic , Phosphoproteins/genetics , Phosphoproteins/immunology , Protein Domains , Rats , Recombinant Fusion Proteins/genetics , SARS-CoV-2/genetics , Sf9 Cells , Spike Glycoprotein, Coronavirus/genetics , Spodoptera , Tetanus Toxoid/genetics , Vero Cells
16.
PLoS Comput Biol ; 17(3): e1008785, 2021 03.
Article in English | MEDLINE | ID: covidwho-1181165

ABSTRACT

Non-human primates infected with SARS-CoV-2 exhibit mild clinical signs. Here we used a mathematical model to characterize in detail the viral dynamics in 31 cynomolgus macaques for which nasopharyngeal and tracheal viral load were frequently assessed. We identified that infected cells had a large burst size (>104 virus) and a within-host reproductive basic number of approximately 6 and 4 in nasopharyngeal and tracheal compartment, respectively. After peak viral load, infected cells were rapidly lost with a half-life of 9 hours, with no significant association between cytokine elevation and clearance, leading to a median time to viral clearance of 10 days, consistent with observations in mild human infections. Given these parameter estimates, we predict that a prophylactic treatment blocking 90% of viral production or viral infection could prevent viral growth. In conclusion, our results provide estimates of SARS-CoV-2 viral kinetic parameters in an experimental model of mild infection and they provide means to assess the efficacy of future antiviral treatments.


Subject(s)
COVID-19/virology , Macaca fascicularis/virology , SARS-CoV-2/physiology , Animals , Antiviral Agents/pharmacology , Basic Reproduction Number , COVID-19/blood , COVID-19/prevention & control , Cytokines/blood , Disease Models, Animal , Nasopharynx/virology , SARS-CoV-2/drug effects , Trachea/virology , Viral Load , Virus Replication/drug effects
17.
J Med Chem ; 64(8): 5001-5017, 2021 04 22.
Article in English | MEDLINE | ID: covidwho-1174625

ABSTRACT

A discovery program targeting respiratory syncytial virus (RSV) identified C-nucleoside 4 (RSV A2 EC50 = 530 nM) as a phenotypic screening lead targeting the RSV RNA-dependent RNA polymerase (RdRp). Prodrug exploration resulted in the discovery of remdesivir (1, GS-5734) that is >30-fold more potent than 4 against RSV in HEp-2 and NHBE cells. Metabolism studies in vitro confirmed the rapid formation of the active triphosphate metabolite, 1-NTP, and in vivo studies in cynomolgus and African Green monkeys demonstrated a >10-fold higher lung tissue concentration of 1-NTP following molar normalized IV dosing of 1 compared to that of 4. A once daily 10 mg/kg IV administration of 1 in an African Green monkey RSV model demonstrated a >2-log10 reduction in the peak lung viral load. These early data following the discovery of 1 supported its potential as a novel treatment for RSV prior to its development for Ebola and approval for COVID-19 treatment.


Subject(s)
Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Antiviral Agents/pharmacology , Prodrugs/pharmacology , Respiratory Syncytial Virus Infections/drug therapy , Respiratory Syncytial Virus, Human/drug effects , Adenosine Monophosphate/pharmacology , Alanine/pharmacology , Animals , Antiviral Agents/chemistry , Antiviral Agents/pharmacokinetics , Caco-2 Cells , Cells, Cultured , Chlorocebus aethiops , Disease Models, Animal , Dogs , Drug Evaluation, Preclinical/methods , Epithelial Cells/virology , Humans , Macaca fascicularis , Male , Prodrugs/chemistry , Prodrugs/pharmacokinetics , Rats, Sprague-Dawley , Respiratory Syncytial Virus Infections/virology , Structure-Activity Relationship , Tissue Distribution , Tubercidin/analogs & derivatives , Tubercidin/chemistry , Viral Load
20.
Proc Natl Acad Sci U S A ; 118(11)2021 03 16.
Article in English | MEDLINE | ID: covidwho-1127220

ABSTRACT

The COVID-19 pandemic has reemphasized the need to identify safe and scalable therapeutics to slow or reverse symptoms of disease caused by newly emerging and reemerging viral pathogens. Recent clinical successes of monoclonal antibodies (mAbs) in therapy for viral infections demonstrate that mAbs offer a solution for these emerging biothreats. We have explored this with respect to Junin virus (JUNV), an arenavirus classified as a category A high-priority agent and the causative agent of Argentine hemorrhagic fever (AHF). There are currently no Food and Drug Administration-approved drugs available for preventing or treating AHF, although immune plasma from convalescent patients is used routinely to treat active infections. However, immune plasma is severely limited in quantity, highly variable in quality, and poses significant safety risks including the transmission of transfusion-borne diseases. mAbs offer a highly specific and consistently potent alternative to immune plasma that can be manufactured at large scale. We previously described a chimeric mAb, cJ199, that provided protection in a guinea pig model of AHF. To adapt this mAb to a format more suitable for clinical use, we humanized the mAb (hu199) and evaluated it in a cynomolgus monkey model of AHF with two JUNV isolates, Romero and Espindola. While untreated control animals experienced 100% lethality, all animals treated with hu199 at 6 d postinoculation (dpi) survived, and 50% of animals treated at 8 dpi survived. mAbs like hu199 may offer a safer, scalable, and more reproducible alternative to immune plasma for rare viral diseases that have epidemic potential.


Subject(s)
Antibodies, Monoclonal, Humanized/pharmacology , Antibodies, Viral/pharmacology , Hemorrhagic Fever, American/prevention & control , Junin virus/metabolism , Animals , Disease Models, Animal , Female , Guinea Pigs , Hemorrhagic Fever, American/blood , Humans , Macaca fascicularis
SELECTION OF CITATIONS
SEARCH DETAIL
...