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1.
Cell ; 184(19): 4969-4980.e15, 2021 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-34332650

RESUMEN

Memory B cell reserves can generate protective antibodies against repeated SARS-CoV-2 infections, but with unknown reach from original infection to antigenically drifted variants. We charted memory B cell receptor-encoded antibodies from 19 COVID-19 convalescent subjects against SARS-CoV-2 spike (S) and found seven major antibody competition groups against epitopes recurrently targeted across individuals. Inclusion of published and newly determined structures of antibody-S complexes identified corresponding epitopic regions. Group assignment correlated with cross-CoV-reactivity breadth, neutralization potency, and convergent antibody signatures. Although emerging SARS-CoV-2 variants of concern escaped binding by many members of the groups associated with the most potent neutralizing activity, some antibodies in each of those groups retained affinity-suggesting that otherwise redundant components of a primary immune response are important for durable protection from evolving pathogens. Our results furnish a global atlas of S-specific memory B cell repertoires and illustrate properties driving viral escape and conferring robustness against emerging variants.

2.
PLoS Biol ; 21(2): e3001922, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36780432

RESUMEN

A universal taxonomy of viruses is essential for a comprehensive view of the virus world and for communicating the complicated evolutionary relationships among viruses. However, there are major differences in the conceptualisation and approaches to virus classification and nomenclature among virologists, clinicians, agronomists, and other interested parties. Here, we provide recommendations to guide the construction of a coherent and comprehensive virus taxonomy, based on expert scientific consensus. Firstly, assignments of viruses should be congruent with the best attainable reconstruction of their evolutionary histories, i.e., taxa should be monophyletic. This fundamental principle for classification of viruses is currently included in the International Committee on Taxonomy of Viruses (ICTV) code only for the rank of species. Secondly, phenotypic and ecological properties of viruses may inform, but not override, evolutionary relatedness in the placement of ranks. Thirdly, alternative classifications that consider phenotypic attributes, such as being vector-borne (e.g., "arboviruses"), infecting a certain type of host (e.g., "mycoviruses," "bacteriophages") or displaying specific pathogenicity (e.g., "human immunodeficiency viruses"), may serve important clinical and regulatory purposes but often create polyphyletic categories that do not reflect evolutionary relationships. Nevertheless, such classifications ought to be maintained if they serve the needs of specific communities or play a practical clinical or regulatory role. However, they should not be considered or called taxonomies. Finally, while an evolution-based framework enables viruses discovered by metagenomics to be incorporated into the ICTV taxonomy, there are essential requirements for quality control of the sequence data used for these assignments. Combined, these four principles will enable future development and expansion of virus taxonomy as the true evolutionary diversity of viruses becomes apparent.


Asunto(s)
Bacteriófagos , Virus , Humanos , Metagenómica , Filogenia , Virus/genética
3.
Nature ; 586(7830): 509-515, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32967005

RESUMEN

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/inmunología
4.
Proc Natl Acad Sci U S A ; 120(38): e2301518120, 2023 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-37695910

RESUMEN

SARS-CoV-2 spike harbors glycans which function as ligands for lectins. Therefore, it should be possible to exploit lectins to target SARS-CoV-2 and inhibit cellular entry by binding glycans on the spike protein. Burkholderia oklahomensis agglutinin (BOA) is an antiviral lectin that interacts with viral glycoproteins via N-linked high mannose glycans. Here, we show that BOA binds to the spike protein and is a potent inhibitor of SARS-CoV-2 viral entry at nanomolar concentrations. Using a variety of biophysical approaches, we demonstrate that the interaction is avidity driven and that BOA cross-links the spike protein into soluble aggregates. Furthermore, using virus neutralization assays, we demonstrate that BOA effectively inhibits all tested variants of concern as well as SARS-CoV 2003, establishing that multivalent glycan-targeting molecules have the potential to act as pan-coronavirus inhibitors.


Asunto(s)
COVID-19 , Humanos , ARN Viral , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Internalización del Virus , Aglutininas , Lectinas , Polisacáridos/farmacología
5.
J Virol ; 98(3): e0185023, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38415596

RESUMEN

Morbilliviruses are members of the family Paramyxoviridae and are known for their ability to cause systemic disease in a variety of mammalian hosts. The prototypic morbillivirus, measles virus (MeV), infects humans and still causes morbidity and mortality in unvaccinated children and young adults. Experimental infection studies in non-human primates have contributed to the understanding of measles pathogenesis. However, ethical restrictions call for the development of new animal models. Canine distemper virus (CDV) infects a wide range of animals, including ferrets, and its pathogenesis shares many features with measles. However, wild-type CDV infection is almost always lethal, while MeV infection is usually self-limiting. Here, we made five recombinant CDVs, predicted to be attenuated, and compared their pathogenesis to the non-attenuated recombinant CDV in a ferret model. Three viruses were insufficiently attenuated based on clinical signs, fatality, and systemic infection, while one virus was too attenuated. The last candidate virus caused a self-limiting infection associated with transient viremia and viral dissemination to all lymphoid tissues, was shed transiently from the upper respiratory tract, and did not result in acute neurological signs. Additionally, an in-depth phenotyping of the infected white blood cells showed lower infection percentages in all lymphocyte subsets when compared to the non-attenuated CDV. In conclusion, infection models using this candidate virus mimic measles and can be used to study pathogenesis-related questions and to test interventions for morbilliviruses in a natural host species.IMPORTANCEMorbilliviruses are transmitted via the respiratory route but cause systemic disease. The viruses use two cellular receptors to infect myeloid, lymphoid, and epithelial cells. Measles virus (MeV) remains an important cause of morbidity and mortality in humans, requiring animal models to study pathogenesis or intervention strategies. Experimental MeV infections in non-human primates are restricted by ethical and practical constraints, and animal morbillivirus infections in natural host species have been considered as alternatives. Inoculation of ferrets with wild-type canine distemper virus (CDV) has been used for this purpose, but in most cases, the virus overwhelms the immune system and causes highly lethal disease. Introduction of an additional transcription unit and an additional attenuating point mutation in the polymerase yielded a candidate virus that caused self-limiting disease with transient viremia and virus shedding. This rationally attenuated CDV strain can be used for experimental morbillivirus infections in ferrets that reflect measles in humans.


Asunto(s)
Modelos Animales de Enfermedad , Virus del Moquillo Canino , Hurones , Sarampión , Infecciones por Morbillivirus , Animales , Perros , Humanos , Moquillo/virología , Virus del Moquillo Canino/genética , Sarampión/patología , Virus del Sarampión/genética , Morbillivirus/genética , Infecciones por Morbillivirus/patología , Primates , Viremia
6.
J Virol ; 98(5): e0169323, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38563763

RESUMEN

In the early COVID-19 pandemic with urgent need for countermeasures, we aimed at developing a replicating viral vaccine using the highly efficacious measles vaccine as vector, a promising technology with prior clinical proof of concept. Building on our successful pre-clinical development of a measles virus (MV)-based vaccine candidate against the related SARS-CoV, we evaluated several recombinant MV expressing codon-optimized SARS-CoV-2 spike glycoprotein. Candidate V591 expressing a prefusion-stabilized spike through introduction of two proline residues in HR1 hinge loop, together with deleted S1/S2 furin cleavage site and additional inactivation of the endoplasmic reticulum retrieval signal, was the most potent in eliciting neutralizing antibodies in mice. After single immunization, V591 induced similar neutralization titers as observed in sera of convalescent patients. The cellular immune response was confirmed to be Th1 skewed. V591 conferred long-lasting protection against SARS-CoV-2 challenge in a murine model with marked decrease in viral RNA load, absence of detectable infectious virus loads, and reduced lesions in the lungs. V591 was furthermore efficacious in an established non-human primate model of disease (see companion article [S. Nambulli, N. Escriou, L. J. Rennick, M. J. Demers, N. L. Tilston-Lunel et al., J Virol 98:e01762-23, 2024, https://doi.org/10.1128/jvi.01762-23]). Thus, V591 was taken forward into phase I/II clinical trials in August 2020. Unexpected low immunogenicity in humans (O. Launay, C. Artaud, M. Lachâtre, M. Ait-Ahmed, J. Klein et al., eBioMedicine 75:103810, 2022, https://doi.org/10.1016/j.ebiom.2021.103810) revealed that the underlying mechanisms for resistance or sensitivity to pre-existing anti-measles immunity are not yet understood. Different hypotheses are discussed here, which will be important to investigate for further development of the measles-vectored vaccine platform.IMPORTANCESARS-CoV-2 emerged at the end of 2019 and rapidly spread worldwide causing the COVID-19 pandemic that urgently called for vaccines. We developed a vaccine candidate using the highly efficacious measles vaccine as vector, a technology which has proved highly promising in clinical trials for other pathogens. We report here and in the companion article by Nambulli et al. (J Virol 98:e01762-23, 2024, https://doi.org/10.1128/jvi.01762-23) the design, selection, and preclinical efficacy of the V591 vaccine candidate that was moved into clinical development in August 2020, 7 months after the identification of SARS-CoV-2 in Wuhan. These unique in-human trials of a measles vector-based COVID-19 vaccine revealed insufficient immunogenicity, which may be the consequence of previous exposure to the pediatric measles vaccine. The three studies together in mice, primates, and humans provide a unique insight into the measles-vectored vaccine platform, raising potential limitations of surrogate preclinical models and calling for further refinement of the platform.


Asunto(s)
Vacunas contra la COVID-19 , Virus del Sarampión , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Animales , Femenino , Humanos , Ratones , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , COVID-19/prevención & control , COVID-19/inmunología , COVID-19/virología , Vacunas contra la COVID-19/inmunología , Modelos Animales de Enfermedad , Vectores Genéticos , Vacuna Antisarampión/inmunología , Vacuna Antisarampión/genética , Virus del Sarampión/inmunología , Virus del Sarampión/genética , Ratones Endogámicos BALB C , SARS-CoV-2/inmunología , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/genética
7.
J Virol ; 98(5): e0176223, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38563762

RESUMEN

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged at the end of 2019 and is responsible for the largest human pandemic in 100 years. Thirty-four vaccines are currently approved for use worldwide, and approximately 67% of the world population has received a complete primary series of one, yet countries are dealing with new waves of infections, variant viruses continue to emerge, and breakthrough infections are frequent secondary to waning immunity. Here, we evaluate a measles virus (MV)-vectored vaccine expressing a stabilized prefusion SARS-CoV-2 spike (S) protein (MV-ATU3-S2PΔF2A; V591) with demonstrated immunogenicity in mouse models (see companion article [J. Brunet, Z. Choucha, M. Gransagne, H. Tabbal, M.-W. Ku et al., J Virol 98:e01693-23, 2024, https://doi.org/10.1128/jvi.01693-23]) in an established African green monkey model of disease. Animals were vaccinated with V591 or the control vaccine (an equivalent MV-vectored vaccine with an irrelevant antigen) intramuscularly using a prime/boost schedule, followed by challenge with an early pandemic isolate of SARS-CoV-2 at 56 days post-vaccination. Pre-challenge, only V591-vaccinated animals developed S-specific antibodies that had virus-neutralizing activity as well as S-specific T cells. Following the challenge, V591-vaccinated animals had lower infectious virus and viral (v) RNA loads in mucosal secretions and stopped shedding virus in these secretions earlier. vRNA loads were lower in these animals in respiratory and gastrointestinal tract tissues at necropsy. This correlated with a lower disease burden in the lungs as quantified by PET/CT at early and late time points post-challenge and by pathological analysis at necropsy.IMPORTANCESevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the largest human pandemic in 100 years. Even though vaccines are currently available, countries are dealing with new waves of infections, variant viruses continue to emerge, breakthrough infections are frequent, and vaccine hesitancy persists. This study uses a safe and effective measles vaccine as a platform for vaccination against SARS-CoV-2. The candidate vaccine was used to vaccinate African green monkeys (AGMs). All vaccinated AGMs developed robust antigen-specific immune responses. After challenge, these AGMs produced less virus in mucosal secretions, for a shorter period, and had a reduced disease burden in the lungs compared to control animals. At necropsy, lower levels of viral RNA were detected in tissue samples from vaccinated animals, and the lungs of these animals lacked the histologic hallmarks of SARS-CoV-2 disease observed exclusively in the control AGMs.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Virus del Sarampión , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Animales , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/genética , Chlorocebus aethiops , SARS-CoV-2/inmunología , SARS-CoV-2/genética , COVID-19/prevención & control , COVID-19/inmunología , COVID-19/virología , Virus del Sarampión/inmunología , Virus del Sarampión/genética , Vacunas contra la COVID-19/inmunología , Humanos , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Vectores Genéticos , Células Vero , Pandemias/prevención & control , Femenino , Betacoronavirus/inmunología , Betacoronavirus/genética , Neumonía Viral/prevención & control , Neumonía Viral/virología , Neumonía Viral/inmunología , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/virología , Infecciones por Coronavirus/veterinaria , Vacunas Virales/inmunología , Vacunas Virales/genética , Vacunas Virales/administración & dosificación , Modelos Animales de Enfermedad
8.
J Virol ; 98(1): e0179123, 2024 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-38168672

RESUMEN

In the United States (US), biosafety and biosecurity oversight of research on viruses is being reappraised. Safety in virology research is paramount and oversight frameworks should be reviewed periodically. Changes should be made with care, however, to avoid impeding science that is essential for rapidly reducing and responding to pandemic threats as well as addressing more common challenges caused by infectious diseases. Decades of research uniquely positioned the US to be able to respond to the COVID-19 crisis with astounding speed, delivering life-saving vaccines within a year of identifying the virus. We should embolden and empower this strength, which is a vital part of protecting the health, economy, and security of US citizens. Herein, we offer our perspectives on priorities for revised rules governing virology research in the US.


Asunto(s)
Investigación Biomédica , Contención de Riesgos Biológicos , Virología , Humanos , COVID-19 , Estados Unidos , Virus , Investigación Biomédica/normas
9.
Proc Natl Acad Sci U S A ; 119(43): e2209405119, 2022 10 25.
Artículo en Inglés | MEDLINE | ID: mdl-36251995

RESUMEN

Feline morbillivirus (FeMV) is a recently discovered pathogen of domestic cats and has been classified as a morbillivirus in the Paramyxovirus family. We determined the complete sequence of FeMVUS5 directly from an FeMV-positive urine sample without virus isolation or cell passage. Sequence analysis of the viral genome revealed potential divergence from characteristics of archetypal morbilliviruses. First, the virus lacks the canonical polybasic furin cleavage signal in the fusion (F) glycoprotein. Second, conserved amino acids in the hemagglutinin (H) glycoprotein used by all other morbilliviruses for binding and/or fusion activation with the cellular receptor CD150 (signaling lymphocyte activation molecule [SLAM]/F1) are absent. We show that, despite this sequence divergence, FeMV H glycoprotein uses feline CD150 as a receptor and cannot use human CD150. We demonstrate that the protease responsible for cleaving the FeMV F glycoprotein is a cathepsin, making FeMV a unique morbillivirus and more similar to the closely related zoonotic Nipah and Hendra viruses. We developed a reverse genetics system for FeMVUS5 and generated recombinant viruses expressing Venus fluorescent protein from an additional transcription unit located either between the phospho-protein (P) and matrix (M) genes or the H and large (L) genes of the genome. We used these recombinant FeMVs to establish a natural infection and demonstrate that FeMV causes an acute morbillivirus-like disease in the cat. Virus was shed in the urine and detectable in the kidneys at later time points. This opens the door for long-term studies to address the postulated role of this morbillivirus in the development of chronic kidney disease.


Asunto(s)
Infecciones por Morbillivirus , Morbillivirus , Aminoácidos , Animales , Catepsinas/genética , Gatos , Furina , Hemaglutininas , Humanos , Riñón , Morbillivirus/genética , Infecciones por Morbillivirus/veterinaria
10.
Emerg Infect Dis ; 30(8)2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38914418

RESUMEN

Examining the persistence of highly pathogenic avian influenza A(H5N1) from cattle and human influenza A(H1N1)pdm09 pandemic viruses in unpasteurized milk revealed that both remain infectious on milking equipment materials for several hours. Those findings highlight the risk for H5N1 virus transmission to humans from contaminated surfaces during the milking process.

11.
J Virol ; 97(2): e0008923, 2023 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-36700640

RESUMEN

Viruses have brought humanity many challenges: respiratory infection, cancer, neurological impairment and immunosuppression to name a few. Virology research over the last 60+ years has responded to reduce this disease burden with vaccines and antivirals. Despite this long history, the COVID-19 pandemic has brought unprecedented attention to the field of virology. Some of this attention is focused on concern about the safe conduct of research with human pathogens. A small but vocal group of individuals has seized upon these concerns - conflating legitimate questions about safely conducting virus-related research with uncertainties over the origins of SARS-CoV-2. The result has fueled public confusion and, in many instances, ill-informed condemnation of virology. With this article, we seek to promote a return to rational discourse. We explain the use of gain-of-function approaches in science, discuss the possible origins of SARS-CoV-2 and outline current regulatory structures that provide oversight for virological research in the United States. By offering our expertise, we - a broad group of working virologists - seek to aid policy makers in navigating these controversial issues. Balanced, evidence-based discourse is essential to addressing public concern while maintaining and expanding much-needed research in virology.


Asunto(s)
Investigación , Virología , Virosis , Humanos , COVID-19/prevención & control , Difusión de la Información , Pandemias/prevención & control , Formulación de Políticas , Investigación/normas , Investigación/tendencias , SARS-CoV-2 , Virología/normas , Virología/tendencias , Virosis/prevención & control , Virosis/virología , Virus
12.
J Infect Dis ; 228(Suppl 6): S390-S397, 2023 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-37849400

RESUMEN

The Paramyxoviridae family includes established human pathogens such as measles virus, mumps virus, and the human parainfluenza viruses; highly lethal zoonotic pathogens such as Nipah virus; and a number of recently identified agents, such as Sosuga virus, which remain poorly understood. The high human-to-human transmission rate of paramyxoviruses such as measles virus, high case fatality rate associated with other family members such as Nipah virus, and the existence of poorly characterized zoonotic pathogens raise concern that known and unknown paramyxoviruses have significant pandemic potential. In this review, the general life cycle, taxonomic relationships, and viral pathogenesis are described for paramyxoviruses that cause both systemic and respiratory system-restricted infections. Next, key gaps in critical areas are presented, following detailed conversations with subject matter experts and based on the current literature. Finally, we present an assessment of potential prototype pathogen candidates that could be used as models to study this important virus family, including assessment of the strengths and weaknesses of each potential prototype.


Asunto(s)
Virus Nipah , Vacunas , Humanos , Pandemias , Paramyxoviridae , Antivirales/uso terapéutico
13.
J Gen Virol ; 104(8)2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37622664

RESUMEN

In April 2023, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by one new family, 14 new genera, and 140 new species. Two genera and 538 species were renamed. One species was moved, and four were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.


Asunto(s)
Virus ARN de Sentido Negativo , Virus ARN , Virus ARN/genética , ARN Polimerasa Dependiente del ARN/genética
14.
J Appl Toxicol ; 43(5): 719-733, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36480160

RESUMEN

MV-LASV is an investigational measles Schwarz-based vaccine for the prevention of Lassa fever. A repeated-dose toxicity study in cynomolgus macaques was performed to assess the biodistribution and local and systemic toxicological effects. Monkeys received three immunizations of MV-LASV or saline intramuscularly with a 2-week interval. An increase in anti-measles antibodies confirmed the reaction of the immune system to the vaccine backbone. Clinical observations, body weight, body temperature, local tolerance, electrocardiogram parameters, various clinical pathology parameters (hematology, coagulation urinalysis, serum chemistry, and C-reactive protein) were monitored. Gross pathology and histopathology of various tissues were evaluated. MV-LASV induced a mild increase in fibrinogen and C-reactive protein concentrations. This coincided with microscopic inflammation at the injection sites which partially or fully resolved following a 3-week recovery period. Viral RNA was found in secondary lymphoid organs and injection sites and gall bladder. No viral shedding to the environment was observed. Overall, the vaccine was locally and systemically well tolerated, supporting a first-in-human study.


Asunto(s)
Fiebre de Lassa , Vacuna Antisarampión , Animales , Humanos , Distribución Tisular , Proteína C-Reactiva , Macaca fascicularis , Fiebre de Lassa/prevención & control , Vacunas Sintéticas
15.
Antimicrob Agents Chemother ; 66(12): e0103222, 2022 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-36346232

RESUMEN

Human respiratory syncytial virus (hRSV) infection is a leading cause of severe respiratory tract infections. Effective, directly acting antivirals against hRSV are not available. We aimed to discover new and chemically diverse candidates to enrich the hRSV drug development pipeline. We used a two-step screen that interrogates compound efficacy after primary infection and a consecutive virus passaging. We resynthesized selected hit molecules and profiled their activities with hRSV lentiviral pseudotype cell entry, replicon, and time-of-addition assays. The breadth of antiviral activity was tested against recent RSV clinical strains and human coronavirus (hCoV-229E), and in pseudotype-based entry assays with non-RSV viruses. Screening 6,048 molecules, we identified 23 primary candidates, of which 13 preferentially scored in the first and 10 in the second rounds of infection, respectively. Two of these molecules inhibited hRSV cell entry and selected for F protein resistance within the fusion peptide. One molecule inhibited transcription/replication in hRSV replicon assays, did not select for phenotypic hRSV resistance and was active against non-hRSV viruses, including hCoV-229E. One compound, identified in the second round of infection, did not measurably inhibit hRSV cell entry or replication/transcription. It selected for two coding mutations in the G protein and was highly active in differentiated BCi-NS1.1 lung cells. In conclusion, we identified four new hRSV inhibitor candidates with different modes of action. Our findings build an interesting platform for medicinal chemistry-guided derivatization approaches followed by deeper phenotypical characterization in vitro and in vivo with the aim of developing highly potent hRSV drugs.


Asunto(s)
Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Infecciones del Sistema Respiratorio , Humanos , Infecciones por Virus Sincitial Respiratorio/tratamiento farmacológico , Virus Sincitial Respiratorio Humano/genética , Antivirales/uso terapéutico , Pulmón
16.
PLoS Pathog ; 16(10): e1008253, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-33031460

RESUMEN

Measles is characterized by fever and a maculopapular skin rash, which is accompanied by immune clearance of measles virus (MV)-infected cells. Histopathological analyses of skin biopsies from humans and non-human primates (NHPs) with measles rash have identified MV-infected keratinocytes and mononuclear cells in the epidermis, around hair follicles and near sebaceous glands. Here, we address the pathogenesis of measles skin rash by combining data from experimentally infected NHPs, ex vivo infection of human skin sheets and in vitro infection of primary human keratinocytes. Analysis of NHP skin samples collected at different time points following MV inoculation demonstrated that infection in the skin precedes onset of rash by several days. MV infection was detected in lymphoid and myeloid cells in the dermis before dissemination to the epidermal leukocytes and keratinocytes. These data were in good concordance with ex vivo MV infections of human skin sheets, in which dermal cells were more targeted than the epidermal cells. To address viral dissemination to the epidermis and to determine whether the dissemination is receptor-dependent, we performed experimental infections of primary keratinocytes collected from healthy donors. These experiments demonstrated that MV infection of keratinocytes is mainly nectin-4-dependent, and differentiated keratinocytes, which express higher levels of nectin-4, are more susceptible to MV infection than proliferating keratinocytes. Based on these data, we propose a model to explain measles skin rash: migrating MV-infected lymphocytes initiate the infection of dermal skin-resident CD150+ immune cells. The infection is subsequently disseminated from the dermal papillae to nectin-4+ keratinocytes in the basal epidermis. Lateral spread of MV infection is observed in the superficial epidermis, most likely due to the higher level of nectin-4 expression on differentiated keratinocytes. Finally, MV-infected cells are cleared by infiltrating immune cells, causing hyperemia and edema, which give the appearance of morbilliform skin rash.


Asunto(s)
Dermis/virología , Epidermis/virología , Queratinocitos/virología , Linfocitos/virología , Sarampión/virología , Células Mieloides/virología , Piel/virología , Animales , Células Cultivadas , Dermis/patología , Epidermis/patología , Humanos , Queratinocitos/patología , Linfocitos/patología , Macaca fascicularis , Sarampión/patología , Virus del Sarampión/aislamiento & purificación , Células Mieloides/patología , Piel/patología
17.
PLoS Pathog ; 16(9): e1008903, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32946524

RESUMEN

Vaccines are urgently needed to combat the global coronavirus disease 2019 (COVID-19) pandemic, and testing of candidate vaccines in an appropriate non-human primate (NHP) model is a critical step in the process. Infection of African green monkeys (AGM) with a low passage human isolate of SARS-CoV-2 by aerosol or mucosal exposure resulted in mild clinical infection with a transient decrease in lung tidal volume. Imaging with human clinical-grade 18F-fluoro-2-deoxy-D-glucose positron emission tomography (18F-FDG PET) co-registered with computed tomography (CT) revealed pulmonary lesions at 4 days post-infection (dpi) that resolved over time. Infectious virus was shed from both respiratory and gastrointestinal (GI) tracts in all animals in a biphasic manner, first between 2-7 dpi followed by a recrudescence at 14-21 dpi. Viral RNA (vRNA) was found throughout both respiratory and gastrointestinal systems at necropsy with higher levels of vRNA found within the GI tract tissues. All animals seroconverted simultaneously for IgM and IgG, which has also been documented in human COVID-19 cases. Young AGM represent an species to study mild/subclinical COVID-19 disease and with possible insights into live virus shedding. Future vaccine evaluation can be performed in AGM with correlates of efficacy being lung lesions by PET/CT, virus shedding, and tissue viral load.


Asunto(s)
Betacoronavirus , Infecciones por Coronavirus/diagnóstico por imagen , Tracto Gastrointestinal/virología , Neumonía Viral/diagnóstico por imagen , Esparcimiento de Virus/fisiología , Animales , COVID-19 , Chlorocebus aethiops , Infecciones por Coronavirus/virología , Pulmón/patología , Pulmón/virología , Pandemias , Neumonía Viral/virología , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , SARS-CoV-2
18.
Arch Virol ; 167(12): 2857-2906, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36437428

RESUMEN

In March 2022, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by two new families (bunyaviral Discoviridae and Tulasviridae), 41 new genera, and 98 new species. Three hundred forty-nine species were renamed and/or moved. The accidentally misspelled names of seven species were corrected. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.


Asunto(s)
Mononegavirales , Virus , Humanos , Mononegavirales/genética , Filogenia
19.
Clin Infect Dis ; 73(3): e815-e821, 2021 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-33507235

RESUMEN

A chimeric antigen receptor-modified T-cell therapy recipient developed severe coronavirus disease 2019, intractable RNAemia, and viral replication lasting >2 months. Premortem endotracheal aspirate contained >2 × 1010 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA copies/mL and infectious virus. Deep sequencing revealed multiple sequence variants consistent with intrahost virus evolution. SARS-CoV-2 humoral and cell-mediated immunity were minimal. Prolonged transmission from immunosuppressed patients is possible.


Asunto(s)
COVID-19 , Receptores Quiméricos de Antígenos , Tratamiento Basado en Trasplante de Células y Tejidos , Humanos , SARS-CoV-2 , Replicación Viral
20.
J Infect Dis ; 221(Suppl 4): S460-S470, 2020 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-32108876

RESUMEN

The error-prone nature of RNA-dependent RNA polymerases drives the diversity of RNA virus populations. Arising within this diversity is a subset of defective viral genomes that retain replication competency, termed defective interfering (DI) genomes. These defects are caused by aberrant viral polymerase reinitiation on the same viral RNA template (deletion DI species) or the nascent RNA strand (copyback DI species). DI genomes have previously been shown to alter the dynamics of a viral population by interfering with normal virus replication and/or by stimulating the innate immune response. In this study, we investigated the ability of artificially produced DI genomes to inhibit Nipah virus (NiV), a highly pathogenic biosafety level 4 paramyxovirus. High multiplicity of infection passaging of both NiV clinical isolates and recombinant NiV in Vero cells generated an extensive DI population from which individual DIs were identified using next-generation sequencing techniques. Assays were established to generate and purify both naturally occurring and in silico-designed DIs as fully encapsidated, infectious virus-like particles termed defective interfering particles (DIPs). We demonstrate that several of these NiV DIP candidates reduced NiV titers by up to 4 logs in vitro. These data represent a proof-of-principle that a therapeutic application of DIPs to combat NiV infections may be an alternative source of antiviral control for this disease.


Asunto(s)
Genoma Viral , Virus Nipah/genética , Virus Nipah/fisiología , Animales , Línea Celular , Chlorocebus aethiops , Cricetinae , Virus Defectuosos , Mesocricetus , Replicación Viral/genética , Replicación Viral/fisiología
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