RESUMO
The SARS-CoV-2 pandemic has caused extreme human suffering and economic harm. We generated and characterized a new mouse-adapted SARS-CoV-2 virus that captures multiple aspects of severe COVID-19 disease in standard laboratory mice. This SARS-CoV-2 model exhibits the spectrum of morbidity and mortality of COVID-19 disease as well as aspects of host genetics, age, cellular tropisms, elevated Th1 cytokines, and loss of surfactant expression and pulmonary function linked to pathological features of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). This model can rapidly access existing mouse resources to elucidate the role of host genetics, underlying molecular mechanisms governing SARS-CoV-2 pathogenesis, and the protective or pathogenic immune responses related to disease severity. The model promises to provide a robust platform for studies of ALI and ARDS to evaluate vaccine and antiviral drug performance, including in the most vulnerable populations (i.e., the aged) using standard laboratory mice.
Assuntos
Lesão Pulmonar Aguda/patologia , Betacoronavirus/patogenicidade , Infecções por Coronavirus/patologia , Pneumonia Viral/patologia , Animais , Betacoronavirus/isolamento & purificação , Betacoronavirus/fisiologia , COVID-19 , Linhagem Celular , Quimiocinas/sangue , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/virologia , Citocinas/sangue , Modelos Animais de Doenças , Feminino , Humanos , Pulmão/patologia , Pulmão/fisiologia , Pulmão/virologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Pandemias , Pneumonia Viral/mortalidade , Pneumonia Viral/virologia , Síndrome do Desconforto Respiratório/patologia , SARS-CoV-2 , Índice de Gravidade de Doença , Taxa de SobrevidaRESUMO
The mode of acquisition and causes for the variable clinical spectrum of coronavirus disease 2019 (COVID-19) remain unknown. We utilized a reverse genetics system to generate a GFP reporter virus to explore severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogenesis and a luciferase reporter virus to demonstrate sera collected from SARS and COVID-19 patients exhibited limited cross-CoV neutralization. High-sensitivity RNA in situ mapping revealed the highest angiotensin-converting enzyme 2 (ACE2) expression in the nose with decreasing expression throughout the lower respiratory tract, paralleled by a striking gradient of SARS-CoV-2 infection in proximal (high) versus distal (low) pulmonary epithelial cultures. COVID-19 autopsied lung studies identified focal disease and, congruent with culture data, SARS-CoV-2-infected ciliated and type 2 pneumocyte cells in airway and alveolar regions, respectively. These findings highlight the nasal susceptibility to SARS-CoV-2 with likely subsequent aspiration-mediated virus seeding to the lung in SARS-CoV-2 pathogenesis. These reagents provide a foundation for investigations into virus-host interactions in protective immunity, host susceptibility, and virus pathogenesis.
Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Pneumonia Viral/patologia , Pneumonia Viral/virologia , Sistema Respiratório/virologia , Genética Reversa/métodos , Idoso , Enzima de Conversão de Angiotensina 2 , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , COVID-19 , Linhagem Celular , Células Cultivadas , Chlorocebus aethiops , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/terapia , Fibrose Cística/patologia , DNA Recombinante , Feminino , Furina/metabolismo , Humanos , Imunização Passiva , Pulmão/metabolismo , Pulmão/patologia , Pulmão/virologia , Masculino , Pessoa de Meia-Idade , Mucosa Nasal/metabolismo , Mucosa Nasal/patologia , Mucosa Nasal/virologia , Pandemias , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/imunologia , Sistema Respiratório/patologia , SARS-CoV-2 , Serina Endopeptidases/metabolismo , Células Vero , Virulência , Replicação Viral , Soroterapia para COVID-19RESUMO
A safe, effective, and scalable vaccine is needed to halt the ongoing SARS-CoV-2 pandemic. We describe the structure-based design of self-assembling protein nanoparticle immunogens that elicit potent and protective antibody responses against SARS-CoV-2 in mice. The nanoparticle vaccines display 60 SARS-CoV-2 spike receptor-binding domains (RBDs) in a highly immunogenic array and induce neutralizing antibody titers 10-fold higher than the prefusion-stabilized spike despite a 5-fold lower dose. Antibodies elicited by the RBD nanoparticles target multiple distinct epitopes, suggesting they may not be easily susceptible to escape mutations, and exhibit a lower binding:neutralizing ratio than convalescent human sera, which may minimize the risk of vaccine-associated enhanced respiratory disease. The high yield and stability of the assembled nanoparticles suggest that manufacture of the nanoparticle vaccines will be highly scalable. These results highlight the utility of robust antigen display platforms and have launched cGMP manufacturing efforts to advance the SARS-CoV-2-RBD nanoparticle vaccine into the clinic.
Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Nanopartículas/química , Domínios Proteicos/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/química , Vacinação , Adolescente , Adulto , Idoso , Animais , COVID-19/virologia , Chlorocebus aethiops , Estudos de Coortes , Epitopos/imunologia , Feminino , Células HEK293 , Humanos , Macaca nemestrina , Masculino , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Células Vero , Adulto JovemRESUMO
Vaccine-associated enhanced respiratory disease (VAERD) was previously observed in some preclinical models of severe acute respiratory syndrome (SARS) and MERS coronavirus vaccines. We used the SARS coronavirus 2 (SARS-CoV-2) mouse-adapted, passage 10, lethal challenge virus (MA10) mouse model of acute lung injury to evaluate the immune response and potential for immunopathology in animals vaccinated with research-grade mRNA-1273. Whole-inactivated virus or heat-denatured spike protein subunit vaccines with alum designed to elicit low-potency antibodies and Th2-skewed CD4+ T cells resulted in reduced viral titers and weight loss post challenge but more severe pathological changes in the lung compared to saline-immunized animals. In contrast, a protective dose of mRNA-1273 induced favorable humoral and cellular immune responses that protected from viral replication in the upper and lower respiratory tract upon challenge. A subprotective dose of mRNA-1273 reduced viral replication and limited histopathological manifestations compared to animals given saline. Overall, our findings demonstrate an immunological signature associated with antiviral protection without disease enhancement following vaccination with mRNA-1273.
Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , Interações Hospedeiro-Patógeno/imunologia , SARS-CoV-2/imunologia , Vacinas Sintéticas/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Biópsia , Vacinas contra COVID-19/administração & dosagem , Modelos Animais de Doenças , Humanos , Imunoglobulina G , Imuno-Histoquímica , Camundongos , Avaliação de Resultados em Cuidados de Saúde , RNA Mensageiro , Glicoproteína da Espícula de Coronavírus/imunologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Vacinas Sintéticas/administração & dosagem , Vacinas de mRNARESUMO
All coronaviruses known to have recently emerged as human pathogens probably originated in bats1. Here we use a single experimental platform based on immunodeficient mice implanted with human lung tissue (hereafter, human lung-only mice (LoM)) to demonstrate the efficient in vivo replication of severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), as well as two endogenous SARS-like bat coronaviruses that show potential for emergence as human pathogens. Virus replication in this model occurs in bona fide human lung tissue and does not require any type of adaptation of the virus or the host. Our results indicate that bats contain endogenous coronaviruses that are capable of direct transmission to humans. Our detailed analysis of in vivo infection with SARS-CoV-2 in human lung tissue from LoM showed a predominant infection of human lung epithelial cells, including type-2 pneumocytes that are present in alveoli and ciliated airway cells. Acute infection with SARS-CoV-2 was highly cytopathic and induced a robust and sustained type-I interferon and inflammatory cytokine and chemokine response. Finally, we evaluated a therapeutic and pre-exposure prophylaxis strategy for SARS-CoV-2 infection. Our results show that therapeutic and prophylactic administration of EIDD-2801-an oral broad-spectrum antiviral agent that is currently in phase II/III clinical trials-markedly inhibited SARS-CoV-2 replication in vivo, and thus has considerable potential for the prevention and treatment of COVID-19.
Assuntos
Tratamento Farmacológico da COVID-19 , COVID-19/prevenção & controle , Citidina/análogos & derivados , Hidroxilaminas/administração & dosagem , Hidroxilaminas/uso terapêutico , Administração Oral , Células Epiteliais Alveolares/imunologia , Células Epiteliais Alveolares/patologia , Células Epiteliais Alveolares/virologia , Animais , COVID-19/imunologia , Quimioprevenção , Quirópteros/virologia , Ensaios Clínicos Fase II como Assunto , Ensaios Clínicos Fase III como Assunto , Citidina/administração & dosagem , Citidina/uso terapêutico , Citocinas/imunologia , Células Epiteliais/virologia , Feminino , Xenoenxertos , Humanos , Imunidade Inata , Interferon Tipo I/imunologia , Pulmão/imunologia , Pulmão/patologia , Pulmão/virologia , Transplante de Pulmão , Masculino , Camundongos , Profilaxia Pós-Exposição , Profilaxia Pré-Exposição , SARS-CoV-2/imunologia , SARS-CoV-2/patogenicidade , Replicação ViralRESUMO
Coronaviruses are prone to transmission to new host species, as recently demonstrated by the spread to humans of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the coronavirus disease 2019 (COVID-19) pandemic1. Small animal models that recapitulate SARS-CoV-2 disease are needed urgently for rapid evaluation of medical countermeasures2,3. SARS-CoV-2 cannot infect wild-type laboratory mice owing to inefficient interactions between the viral spike protein and the mouse orthologue of the human receptor, angiotensin-converting enzyme 2 (ACE2)4. Here we used reverse genetics5 to remodel the interaction between SARS-CoV-2 spike protein and mouse ACE2 and designed mouse-adapted SARS-CoV-2 (SARS-CoV-2 MA), a recombinant virus that can use mouse ACE2 for entry into cells. SARS-CoV-2 MA was able to replicate in the upper and lower airways of both young adult and aged BALB/c mice. SARS-CoV-2 MA caused more severe disease in aged mice, and exhibited more clinically relevant phenotypes than those seen in Hfh4-ACE2 transgenic mice, which express human ACE2 under the control of the Hfh4 (also known as Foxj1) promoter. We demonstrate the utility of this model using vaccine-challenge studies in immune-competent mice with native expression of mouse ACE2. Finally, we show that the clinical candidate interferon-λ1a (IFN-λ1a) potently inhibits SARS-CoV-2 replication in primary human airway epithelial cells in vitro-both prophylactic and therapeutic administration of IFN-λ1a diminished SARS-CoV-2 replication in mice. In summary, the mouse-adapted SARS-CoV-2 MA model demonstrates age-related disease pathogenesis and supports the clinical use of pegylated IFN-λ1a as a treatment for human COVID-196.
Assuntos
Betacoronavirus , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/prevenção & controle , Modelos Animais de Doenças , Interferons/farmacologia , Interferons/uso terapêutico , Interleucinas/farmacologia , Interleucinas/uso terapêutico , Pandemias/prevenção & controle , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/prevenção & controle , Vacinas Virais/imunologia , Envelhecimento/imunologia , Enzima de Conversão de Angiotensina 2 , Animais , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , COVID-19 , Vacinas contra COVID-19 , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Feminino , Fatores de Transcrição Forkhead/genética , Humanos , Interferon-alfa/administração & dosagem , Interferon-alfa/farmacologia , Interferon-alfa/uso terapêutico , Interferons/administração & dosagem , Interleucinas/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Modelos Moleculares , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/genética , Pneumonia Viral/imunologia , Receptores Virais/genética , Receptores Virais/metabolismo , SARS-CoV-2RESUMO
A vaccine for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is needed to control the coronavirus disease 2019 (COVID-19) global pandemic. Structural studies have led to the development of mutations that stabilize Betacoronavirus spike proteins in the prefusion state, improving their expression and increasing immunogenicity1. This principle has been applied to design mRNA-1273, an mRNA vaccine that encodes a SARS-CoV-2 spike protein that is stabilized in the prefusion conformation. Here we show that mRNA-1273 induces potent neutralizing antibody responses to both wild-type (D614) and D614G mutant2 SARS-CoV-2 as well as CD8+ T cell responses, and protects against SARS-CoV-2 infection in the lungs and noses of mice without evidence of immunopathology. mRNA-1273 is currently in a phase III trial to evaluate its efficacy.
Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/imunologia , Pneumonia Viral/prevenção & controle , Vacinas Virais/imunologia , Vacina de mRNA-1273 contra 2019-nCoV , Animais , Anticorpos Neutralizantes/imunologia , Betacoronavirus/genética , Linfócitos T CD8-Positivos/imunologia , COVID-19 , Vacinas contra COVID-19 , Ensaios Clínicos Fase III como Assunto , Infecções por Coronavirus/genética , Infecções por Coronavirus/virologia , Feminino , Pulmão/imunologia , Pulmão/virologia , Camundongos , Mutação , Nariz/imunologia , Nariz/virologia , Pneumonia Viral/virologia , RNA Mensageiro/genética , RNA Viral/genética , SARS-CoV-2 , Células Th1/imunologia , Receptor 4 Toll-Like/agonistas , Receptor 4 Toll-Like/imunologia , Vacinas Virais/química , Vacinas Virais/genéticaRESUMO
Host kinases play essential roles in the host cell cycle, innate immune signaling, the stress response to viral infection, and inflammation. Previous work has demonstrated that coronaviruses specifically target kinase cascades to subvert host cell responses to infection and rely upon host kinase activity to phosphorylate viral proteins to enhance replication. Given the number of kinase inhibitors that are already FDA approved to treat cancers, fibrosis, and other human disease, they represent an attractive class of compounds to repurpose for host-targeted therapies against emerging coronavirus infections. To further understand the host kinome response to betacoronavirus infection, we employed multiplex inhibitory bead mass spectrometry (MIB-MS) following MERS-CoV and SARS-CoV-2 infection of human lung epithelial cell lines. Our MIB-MS analyses revealed activation of mTOR and MAPK signaling following MERS-CoV and SARS-CoV-2 infection, respectively. SARS-CoV-2 host kinome responses were further characterized using paired phosphoproteomics, which identified activation of MAPK, PI3K, and mTOR signaling. Through chemogenomic screening, we found that clinically relevant PI3K/mTOR inhibitors were able to inhibit coronavirus replication at nanomolar concentrations similar to direct-acting antivirals. This study lays the groundwork for identifying broad-acting, host-targeted therapies to reduce betacoronavirus replication that can be rapidly repurposed during future outbreaks and epidemics. The proteomics, phosphoproteomics, and MIB-MS datasets generated in this study are available in the Proteomics Identification Database (PRIDE) repository under project identifiers PXD040897 and PXD040901.
Assuntos
COVID-19 , Hepatite C Crônica , Coronavírus da Síndrome Respiratória do Oriente Médio , Humanos , Antivirais/farmacologia , Inibidores de MTOR , Fosfatidilinositol 3-Quinases , SARS-CoV-2 , Replicação Viral , Coronavírus da Síndrome Respiratória do Oriente Médio/fisiologia , Serina-Treonina Quinases TORRESUMO
The key to battling the COVID-19 pandemic and its potential aftermath is to develop a variety of vaccines that are efficacious and safe, elicit lasting immunity, and cover a range of SARS-CoV-2 variants. Recombinant viral receptor-binding domains (RBDs) are safe vaccine candidates but often have limited efficacy due to the lack of virus-like immunogen display pattern. Here we have developed a novel virus-like nanoparticle (VLP) vaccine that displays 120 copies of SARS-CoV-2 RBD on its surface. This VLP-RBD vaccine mimics virus-based vaccines in immunogen display, which boosts its efficacy, while maintaining the safety of protein-based subunit vaccines. Compared to the RBD vaccine, the VLP-RBD vaccine induced five times more neutralizing antibodies in mice that efficiently blocked SARS-CoV-2 from attaching to its host receptor and potently neutralized the cell entry of variant SARS-CoV-2 strains, SARS-CoV-1, and SARS-CoV-1-related bat coronavirus. These neutralizing immune responses induced by the VLP-RBD vaccine did not wane during the two-month study period. Furthermore, the VLP-RBD vaccine effectively protected mice from SARS-CoV-2 challenge, dramatically reducing the development of clinical signs and pathological changes in immunized mice. The VLP-RBD vaccine provides one potentially effective solution to controlling the spread of SARS-CoV-2.
Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , Imunogenicidade da Vacina , Nanopartículas/uso terapêutico , Enzima de Conversão de Angiotensina 2/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Modelos Animais de Doenças , Desenho de Fármacos , Feminino , Células HEK293 , Humanos , Pulmão/virologia , Camundongos , Camundongos Endogâmicos BALB C , Domínios Proteicos/imunologiaRESUMO
The COVID-19 pandemic is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and has spread worldwide, with millions of cases and more than 1 million deaths to date. The gravity of the situation mandates accelerated efforts to identify safe and effective vaccines. Here, we generated measles virus (MeV)-based vaccine candidates expressing the SARS-CoV-2 spike glycoprotein (S). Insertion of the full-length S protein gene in two different MeV genomic positions resulted in modulated S protein expression. The variant with lower S protein expression levels was genetically stable and induced high levels of effective Th1-biased antibody and T cell responses in mice after two immunizations. In addition to neutralizing IgG antibody responses in a protective range, multifunctional CD8+ and CD4+ T cell responses with S protein-specific killing activity were detected. Upon challenge using a mouse-adapted SARS-CoV-2, virus loads in vaccinated mice were significantly lower, while vaccinated Syrian hamsters revealed protection in a harsh challenge setup using an early-passage human patient isolate. These results are highly encouraging and support further development of MeV-based COVID-19 vaccines.
Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Vírus do Sarampo/imunologia , SARS-CoV-2/imunologia , Células Th1/imunologia , Animais , Anticorpos Antivirais/imunologia , COVID-19/epidemiologia , COVID-19/imunologia , COVID-19/virologia , Vacinas contra COVID-19/administração & dosagem , Vacinas contra COVID-19/genética , Humanos , Vacina contra Sarampo/genética , Vacina contra Sarampo/imunologia , Vírus do Sarampo/genética , Camundongos , Pandemias , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/administração & dosagem , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Linfócitos T/imunologiaRESUMO
Zoonotic coronaviruses represent an ongoing threat, yet the myriads of circulating animal viruses complicate the identification of higher-risk isolates that threaten human health. Swine acute diarrhea syndrome coronavirus (SADS-CoV) is a newly discovered, highly pathogenic virus that likely evolved from closely related HKU2 bat coronaviruses, circulating in Rhinolophus spp. bats in China and elsewhere. As coronaviruses cause severe economic losses in the pork industry and swine are key intermediate hosts of human disease outbreaks, we synthetically resurrected a recombinant virus (rSADS-CoV) as well as a derivative encoding tomato red fluorescent protein (tRFP) in place of ORF3. rSADS-CoV replicated efficiently in a variety of continuous animal and primate cell lines, including human liver and rectal carcinoma cell lines. Of concern, rSADS-CoV also replicated efficiently in several different primary human lung cell types, as well as primary human intestinal cells. rSADS-CoV did not use human coronavirus ACE-2, DPP4, or CD13 receptors for docking and entry. Contemporary human donor sera neutralized the group I human coronavirus NL63, but not rSADS-CoV, suggesting limited human group I coronavirus cross protective herd immunity. Importantly, remdesivir, a broad-spectrum nucleoside analog that is effective against other group 1 and 2 coronaviruses, efficiently blocked rSADS-CoV replication in vitro. rSADS-CoV demonstrated little, if any, replicative capacity in either immune-competent or immunodeficient mice, indicating a critical need for improved animal models. Efficient growth in primary human lung and intestinal cells implicate SADS-CoV as a potential higher-risk emerging coronavirus pathogen that could negatively impact the global economy and human health.
Assuntos
Alphacoronavirus/fisiologia , Infecções por Coronavirus/virologia , Suscetibilidade a Doenças/virologia , Replicação Viral , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/farmacologia , Alanina/análogos & derivados , Alanina/farmacologia , Alphacoronavirus/genética , Alphacoronavirus/crescimento & desenvolvimento , Animais , Células Cultivadas , Chlorocebus aethiops , Infecções por Coronavirus/transmissão , Expressão Gênica , Especificidade de Hospedeiro , Humanos , Proteínas Luminescentes/genética , Camundongos , Células Vero , Replicação Viral/efeitos dos fármacosRESUMO
The global COVID-19 pandemic has sparked intense interest in the rapid development of vaccines as well as animal models to evaluate vaccine candidates and to define immune correlates of protection. We recently reported a mouse-adapted SARS-CoV-2 virus strain (MA10) with the potential to infect wild-type laboratory mice, driving high levels of viral replication in respiratory tract tissues as well as severe clinical and respiratory symptoms, aspects of COVID-19 disease in humans that are important to capture in model systems. We evaluated the immunogenicity and protective efficacy of novel rhesus adenovirus serotype 52 (RhAd52) vaccines against MA10 challenge in mice. Baseline seroprevalence is lower for rhesus adenovirus vectors than for human or chimpanzee adenovirus vectors, making these vectors attractive candidates for vaccine development. We observed that RhAd52 vaccines elicited robust binding and neutralizing antibody titers, which inversely correlated with viral replication after challenge. These data support the development of RhAd52 vaccines and the use of the MA10 challenge virus to screen novel vaccine candidates and to study the immunologic mechanisms that underscore protection from SARS-CoV-2 challenge in wild-type mice. IMPORTANCE We have developed a series of SARS-CoV-2 vaccines using rhesus adenovirus serotype 52 (RhAd52) vectors, which exhibit a lower seroprevalence than human and chimpanzee vectors, supporting their development as novel vaccine vectors or as an alternative adenovirus (Ad) vector for boosting. We sought to test these vaccines using a recently reported mouse-adapted SARS-CoV-2 (MA10) virus to (i) evaluate the protective efficacy of RhAd52 vaccines and (ii) further characterize this mouse-adapted challenge model and probe immune correlates of protection. We demonstrate that RhAd52 vaccines elicit robust SARS-CoV-2-specific antibody responses and protect against clinical disease and viral replication in the lungs. Further, binding and neutralizing antibody titers correlated with protective efficacy. These data validate the MA10 mouse model as a useful tool to screen and study novel vaccine candidates, as well as the development of RhAd52 vaccines for COVID-19.
Assuntos
Vacinas contra Adenovirus/imunologia , Anticorpos Neutralizantes/imunologia , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , Pandemias/prevenção & controle , SARS-CoV-2/imunologia , Infecções por Adenoviridae/imunologia , Adenovirus dos Símios/imunologia , Animais , Anticorpos Antivirais/imunologia , Modelos Animais de Doenças , Feminino , Humanos , Imunogenicidade da Vacina , Macaca mulatta/virologia , Camundongos , Camundongos Endogâmicos BALB C , SARS-CoV-2/patogenicidade , VacinaçãoRESUMO
Traditionally, the emergence of coronaviruses (CoVs) has been attributed to a gain in receptor binding in a new host. Our previous work with severe acute respiratory syndrome (SARS)-like viruses argued that bats already harbor CoVs with the ability to infect humans without adaptation. These results suggested that additional barriers limit the emergence of zoonotic CoV. In this work, we describe overcoming host restriction of two Middle East respiratory syndrome (MERS)-like bat CoVs using exogenous protease treatment. We found that the spike protein of PDF2180-CoV, a MERS-like virus found in a Ugandan bat, could mediate infection of Vero and human cells in the presence of exogenous trypsin. We subsequently show that the bat virus spike can mediate the infection of human gut cells but is unable to infect human lung cells. Using receptor-blocking antibodies, we show that infection with the PDF2180 spike does not require MERS-CoV receptor DPP4 and antibodies developed against the MERS spike receptor-binding domain and S2 portion are ineffective in neutralizing the PDF2180 chimera. Finally, we found that the addition of exogenous trypsin also rescues HKU5-CoV, a second bat group 2c CoV. Together, these results indicate that proteolytic cleavage of the spike, not receptor binding, is the primary infection barrier for these two group 2c CoVs. Coupled with receptor binding, proteolytic activation offers a new parameter to evaluate the emergence potential of bat CoVs and offers a means to recover previously unrecoverable zoonotic CoV strains.IMPORTANCE Overall, our studies demonstrate that proteolytic cleavage is the primary barrier to infection for a subset of zoonotic coronaviruses. Moving forward, the results argue that both receptor binding and proteolytic cleavage of the spike are critical factors that must be considered for evaluating the emergence potential and risk posed by zoonotic coronaviruses. In addition, the findings also offer a novel means to recover previously uncultivable zoonotic coronavirus strains and argue that other tissues, including the digestive tract, could be a site for future coronavirus emergence events in humans.
Assuntos
Coronavírus da Síndrome Respiratória do Oriente Médio/química , Coronavírus da Síndrome Respiratória do Oriente Médio/metabolismo , Receptores Virais/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , Animais , Células CACO-2 , Quirópteros , Chlorocebus aethiops , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/virologia , Humanos , Tripsina , Células Vero , Zoonoses/metabolismo , Zoonoses/virologiaRESUMO
With an ongoing threat posed by circulating zoonotic strains, new strategies are required to prepare for the next emergent coronavirus (CoV). Previously, groups had targeted conserved coronavirus proteins as a strategy to generate live attenuated vaccine strains against current and future CoVs. With this in mind, we explored whether manipulation of CoV NSP16, a conserved 2'O methyltransferase (MTase), could provide a broad attenuation platform against future emergent strains. Using the severe acute respiratory syndrome-CoV mouse model, an NSP16 mutant vaccine was evaluated for protection from heterologous challenge, efficacy in the aging host, and potential for reversion to pathogenesis. Despite some success, concerns for virulence in the aged and potential for reversion makes targeting NSP16 alone an untenable approach. However, combining a 2'O MTase mutation with a previously described CoV fidelity mutant produced a vaccine strain capable of protection from heterologous virus challenge, efficacy in aged mice, and no evidence for reversion. Together, the results indicate that targeting the CoV 2'O MTase in parallel with other conserved attenuating mutations may provide a platform strategy for rapidly generating live attenuated coronavirus vaccines.IMPORTANCE Emergent coronaviruses remain a significant threat to global public health and rapid response vaccine platforms are needed to stem future outbreaks. However, failure of many previous CoV vaccine formulations has clearly highlighted the need to test efficacy under different conditions and especially in vulnerable populations such as the aged and immunocompromised. This study illustrates that despite success in young models, the 2'O methyltransferase mutant carries too much risk for pathogenesis and reversion in vulnerable models to be used as a stand-alone vaccine strategy. Importantly, the 2'O methyltransferase mutation can be paired with other attenuating approaches to provide robust protection from heterologous challenge and in vulnerable populations. Coupled with increased safety and reduced pathogenesis, the study highlights the potential for 2'O methyltransferase attenuation as a major component of future live attenuated coronavirus vaccines.
Assuntos
Infecções por Coronavirus/prevenção & controle , Coronavirus/imunologia , Metiltransferases/genética , Proteínas não Estruturais Virais/genética , Vacinas Virais/genética , Envelhecimento/imunologia , Animais , Proteínas Arqueais/genética , Chlorocebus aethiops , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Modelos Animais de Doenças , Hospedeiro Imunocomprometido , Metilação , Metiltransferases/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Mutação , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/imunologia , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologia , Células Vero , Proteínas não Estruturais Virais/imunologia , Vacinas Virais/imunologia , Replicação ViralRESUMO
BACKGROUND: Prostate ductal branching morphogenesis involves a complex spatiotemporal regulation of cellular proliferation and remodeling of the extracellular matrix (ECM) around the developing ducts. Decorin (Dcn) is a small leucine-rich proteoglycan known to sequester several growth factors and to act as a tumor suppressor in prostate cancer. RESULTS: Dcn expression in the developing prostate paralleled branching morphogenesis and was dynamically regulated by androgen and Hedgehog (Hh) signaling. DCN colocalized with collagen in the periductal stroma and acellular interstitium. Exogenous DCN decreased epithelial proliferation in ex vivo organ cultures of developing prostate, whereas genetic ablation of Dcn resulted in increased epithelial proliferation in the developing prostate. CONCLUSIONS: Dcn expression and localization in the developing prostate is consistent with a primary role in organizing collagen around the developing ducts. Regulation of Dcn expression appears to be complex, involving both androgen and Hh signaling. The growth inhibitory effect of Dcn suggests a unique linkage between a structural proteoglycan and epithelial growth regulation. This may serve to coordinate two elements of the morphogenetic process: ductal growth and organization of the collagen matrix around the nascent duct. Developmental Dynamics 247:679-685, 2018. © 2018 Wiley Periodicals, Inc.
Assuntos
Decorina/metabolismo , Próstata/metabolismo , Transdução de Sinais/fisiologia , Animais , Decorina/genética , Feminino , Masculino , Camundongos , Morfogênese/fisiologia , Técnicas de Cultura de Órgãos , Organogênese/fisiologia , Próstata/embriologia , Próstata/crescimento & desenvolvimentoRESUMO
With severe disease manifestations including microcephaly, congenital malformation, and Guillain-Barré syndrome, Zika virus (ZIKV) remains a persistent global public health threat. Despite antigenic similarities with dengue viruses, structural studies have suggested the extended CD-loop and hydrogen-bonding interaction network within the ZIKV envelope protein contribute to stability differences between the viral families. This enhanced stability may lead to the augmented infection, disease manifestation, and persistence in body fluids seen following ZIKV infection. To examine the role of these motifs in infection, we generated a series of ZIKV recombinant viruses that disrupted the hydrogen-bonding network (350A, 351A, and 350A/351A) or the CD-loop extension (Δ346). Our results demonstrate a key role for the ZIKV extended CD-loop in cell-type-dependent replication, virion stability, and in vivo pathogenesis. Importantly, the Δ346 mutant maintains similar antigenicity to wild-type virus, opening the possibility for its use as a live-attenuated vaccine platform for ZIKV and other clinically relevant flaviviruses.
Assuntos
Domínios e Motivos de Interação entre Proteínas , Proteínas do Envelope Viral/química , Infecção por Zika virus/virologia , Zika virus/fisiologia , Sequência de Aminoácidos , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Linhagem Celular , Chlorocebus aethiops , Modelos Animais de Doenças , Epitopos/imunologia , Feminino , Humanos , Ligação de Hidrogênio , Masculino , Camundongos , Modelos Moleculares , Mutação , Ligação Proteica , Conformação Proteica , Estabilidade Proteica , Relação Estrutura-Atividade , Temperatura , Células Vero , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo , Replicação Viral , Zika virus/patogenicidade , Zika virus/ultraestrutura , Infecção por Zika virus/imunologiaRESUMO
The COVID-19 pandemic led to the rapid and worldwide development of highly effective vaccines against SARS-CoV-2. However, there is significant individual-to-individual variation in vaccine efficacy due to factors including viral variants, host age, immune status, environmental and host genetic factors. Understanding those determinants driving this variation may inform the development of more broadly protective vaccine strategies. While host genetic factors are known to impact vaccine efficacy for respiratory pathogens such as influenza and tuberculosis, the impact of host genetic variation on vaccine efficacy against COVID-19 is not well understood. To model the impact of host genetic variation on SARS-CoV-2 vaccine efficacy, while controlling for the impact of non-genetic factors, we used the Diversity Outbred (DO) mouse model. We found that DO mice immunized against SARS-CoV-2 exhibited high levels of variation in vaccine-induced neutralizing antibody responses. While the majority of the vaccinated mice were protected from virus-induced disease, similar to human populations, we observed vaccine breakthrough in a subset of mice. Importantly, we found that this variation in neutralizing antibody, virus-induced disease, and viral titer is heritable, indicating that the DO serves as a useful model system for studying the contribution of genetic variation of both vaccines and disease outcomes.
RESUMO
Whole virus-based inactivated SARS-CoV-2 vaccines adjuvanted with aluminum hydroxide have been critical to the COVID-19 pandemic response. Although these vaccines are protective against homologous coronavirus infection, the emergence of novel variants and the presence of large zoonotic reservoirs harboring novel heterologous coronaviruses provide significant opportunities for vaccine breakthrough, which raises the risk of adverse outcomes like vaccine-associated enhanced respiratory disease. Here, we use a female mouse model of coronavirus disease to evaluate inactivated vaccine performance against either homologous challenge with SARS-CoV-2 or heterologous challenge with a bat-derived coronavirus that represents a potential emerging disease threat. We show that inactivated SARS-CoV-2 vaccines adjuvanted with aluminum hydroxide can cause enhanced respiratory disease during heterologous infection, while use of an alternative adjuvant does not drive disease and promotes heterologous viral clearance. In this work, we highlight the impact of adjuvant selection on inactivated vaccine safety and efficacy against heterologous coronavirus infection.
Assuntos
Hidróxido de Alumínio , Vacinas contra COVID-19 , COVID-19 , SARS-CoV-2 , Vacinas de Produtos Inativados , Animais , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Feminino , COVID-19/prevenção & controle , COVID-19/imunologia , COVID-19/virologia , Camundongos , Vacinas de Produtos Inativados/imunologia , SARS-CoV-2/imunologia , Hidróxido de Alumínio/administração & dosagem , Modelos Animais de Doenças , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes de Vacinas , Anticorpos Antivirais/imunologia , Camundongos Endogâmicos BALB C , Humanos , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/imunologiaRESUMO
The novel coronavirus SARS-CoV-2 has caused significant global morbidity and mortality and continues to burden patients with persisting neurological dysfunction. COVID-19 survivors develop debilitating symptoms to include neuro-psychological dysfunction, termed "Long COVID", which can cause significant reduction of quality of life. Despite vigorous model development, the possible cause of these symptoms and the underlying pathophysiology of this devastating disease remains elusive. Mouse adapted (MA10) SARS-CoV-2 is a novel mouse-based model of COVID-19 which simulates the clinical symptoms of respiratory distress associated with SARS-CoV-2 infection in mice. In this study, we evaluated the long-term effects of MA10 infection on brain pathology and neuroinflammation. 10-week and 1-year old female BALB/cAnNHsd mice were infected intranasally with 10 4 plaque-forming units (PFU) and 10 3 PFU of SARS-CoV-2 MA10, respectively, and the brain was examined 60 days post-infection (dpi). Immunohistochemical analysis showed a decrease in the neuronal nuclear protein NeuN and an increase in Iba-1 positive amoeboid microglia in the hippocampus after MA10 infection, indicating long-term neurological changes in a brain area which is critical for long-term memory consolidation and processing. Importantly, these changes were seen in 40-50% of infected mice, which correlates to prevalence of LC seen clinically. Our data shows for the first time that MA10 infection induces neuropathological outcomes several weeks after infection at similar rates of observed clinical prevalence of "Long COVID". These observations strengthen the MA10 model as a viable model for study of the long-term effects of SARS-CoV-2 in humans. Establishing the viability of this model is a key step towards the rapid development of novel therapeutic strategies to ameliorate neuroinflammation and restore brain function in those suffering from the persistent cognitive dysfunction of "Long-COVID".