Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 11 de 11
Filter
1.
Nat Methods ; 19(4): 479-485, 2022 04.
Article in English | MEDLINE | ID: covidwho-1764194

ABSTRACT

The recent development of solvent- and polymer-based brain-clearing techniques has advanced our ability to visualize the mammalian nervous system in three dimensions. However, it remains challenging to image the mammalian body en bloc. Here we developed HYBRiD (hydrogel-based reinforcement of three-dimensional imaging solvent-cleared organs (DISCO)), by recombining components of organic- and polymer-based clearing pipelines. We achieved high transparency and protein retention, as well as compatibility with direct fluorescent imaging and immunostaining in cleared mammalian bodies. Using parvalbumin- and somatostatin-Cre models, we demonstrated the utility of HYBRiD for whole-body imaging of genetically encoded fluorescent reporters without antibody enhancement of signals in newborn and juvenile mice. Using K18-hACE2 transgenic mice, HYBRiD enabled perfusion-free clearing and visualization of SARS-CoV-2 infection in a whole mouse chest, revealing macroscopic and microscopic features of viral pathology in the same sample. HYBRiD offers a simple and universal solution to visualize large heterogeneous body parts or entire animals for basic and translational research.


Subject(s)
COVID-19 , Hydrogels , Animals , Imaging, Three-Dimensional/methods , Mammals , Mice , Polymers , SARS-CoV-2 , Solvents
2.
J Virol ; 96(4): e0196921, 2022 02 23.
Article in English | MEDLINE | ID: covidwho-1702819

ABSTRACT

Unlike SARS-CoV-1 and MERS-CoV, infection with SARS-CoV-2, the viral pathogen responsible for COVID-19, is often associated with neurologic symptoms that range from mild to severe, yet increasing evidence argues the virus does not exhibit extensive neuroinvasive properties. We demonstrate SARS-CoV-2 can infect and replicate in human iPSC-derived neurons and that infection shows limited antiviral and inflammatory responses but increased activation of EIF2 signaling following infection as determined by RNA sequencing. Intranasal infection of K18 human ACE2 transgenic mice (K18-hACE2) with SARS-CoV-2 resulted in lung pathology associated with viral replication and immune cell infiltration. In addition, ∼50% of infected mice exhibited CNS infection characterized by wide-spread viral replication in neurons accompanied by increased expression of chemokine (Cxcl9, Cxcl10, Ccl2, Ccl5 and Ccl19) and cytokine (Ifn-λ and Tnf-α) transcripts associated with microgliosis and a neuroinflammatory response consisting primarily of monocytes/macrophages. Microglia depletion via administration of colony-stimulating factor 1 receptor inhibitor, PLX5622, in SARS-CoV-2 infected mice did not affect survival or viral replication but did result in dampened expression of proinflammatory cytokine/chemokine transcripts and a reduction in monocyte/macrophage infiltration. These results argue that microglia are dispensable in terms of controlling SARS-CoV-2 replication in in the K18-hACE2 model but do contribute to an inflammatory response through expression of pro-inflammatory genes. Collectively, these findings contribute to previous work demonstrating the ability of SARS-CoV-2 to infect neurons as well as emphasizing the potential use of the K18-hACE2 model to study immunological and neuropathological aspects related to SARS-CoV-2-induced neurologic disease. IMPORTANCE Understanding the immunological mechanisms contributing to both host defense and disease following viral infection of the CNS is of critical importance given the increasing number of viruses that are capable of infecting and replicating within the nervous system. With this in mind, the present study was undertaken to evaluate the role of microglia in aiding in host defense following experimental infection of the central nervous system (CNS) of K18-hACE2 with SARS-CoV-2, the causative agent of COVID-19. Neurologic symptoms that range in severity are common in COVID-19 patients and understanding immune responses that contribute to restricting neurologic disease can provide important insight into better understanding consequences associated with SARS-CoV-2 infection of the CNS.


Subject(s)
Angiotensin-Converting Enzyme 2/immunology , COVID-19/immunology , Central Nervous System Viral Diseases/immunology , Microglia/immunology , SARS-CoV-2/physiology , Virus Replication/immunology , Angiotensin-Converting Enzyme 2/genetics , Animals , COVID-19/genetics , Central Nervous System/immunology , Central Nervous System/virology , Central Nervous System Viral Diseases/genetics , Central Nervous System Viral Diseases/virology , Chemokines/genetics , Chemokines/immunology , Disease Models, Animal , Humans , Mice , Mice, Transgenic , Microglia/virology , Neurons/immunology , Neurons/virology , Virus Replication/genetics
3.
Sci Transl Med ; 14(637): eabi9215, 2022 03 23.
Article in English | MEDLINE | ID: covidwho-1673344

ABSTRACT

Broadly neutralizing antibodies (bnAbs) to coronaviruses (CoVs) are valuable in their own right as prophylactic and therapeutic reagents to treat diverse CoVs and as templates for rational pan-CoV vaccine design. We recently described a bnAb, CC40.8, from a CoV disease 2019 (COVID-19) convalescent donor that exhibits broad reactivity with human ß-CoVs. Here, we showed that CC40.8 targets the conserved S2 stem helix region of the CoV spike fusion machinery. We determined a crystal structure of CC40.8 Fab with a SARS-CoV-2 S2 stem peptide at 1.6-Å resolution and found that the peptide adopted a mainly helical structure. Conserved residues in ß-CoVs interacted with CC40.8 antibody, thereby providing a molecular basis for its broad reactivity. CC40.8 exhibited in vivo protective efficacy against SARS-CoV-2 challenge in two animal models. In both models, CC40.8-treated animals exhibited less weight loss and reduced lung viral titers compared to controls. Furthermore, we noted that CC40.8-like bnAbs are relatively rare in human COVID-19 infection, and therefore, their elicitation may require rational structure-based vaccine design strategies. Overall, our study describes a target on ß-CoV spike proteins for protective antibodies that may facilitate the development of pan-ß-CoV vaccines.


Subject(s)
COVID-19 , Spike Glycoprotein, Coronavirus , Animals , Antibodies, Neutralizing/metabolism , Antibodies, Viral , COVID-19/immunology , Humans , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology
4.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-293059

ABSTRACT

Unlike SARS-CoV-1 and MERS-CoV, infection with SARS-CoV-2, the viral pathogen responsible for COVID-19, is often associated with neurologic symptoms that range from mild to severe, yet increasing evidence argues the virus does not exhibit extensive neuroinvasive properties. We demonstrate SARS-CoV-2 can infect and replicate in human iPSC-derived neurons and that infection shows limited anti-viral and inflammatory responses but increased activation of EIF2 signaling following infection as determined by RNA sequencing. Intranasal infection of K18 human ACE2 transgenic mice (K18-hACE2) with SARS-CoV-2 resulted in lung pathology associated with viral replication and immune cell infiltration. In addition, ~50% of infected mice exhibited CNS infection characterized by wide-spread viral replication in neurons accompanied by increased expression of chemokine (Cxcl9, Cxcl10, Ccl2, Ccl5 and Ccl19) and cytokine (Ifn-λ and Tnf-α) transcripts associated with microgliosis and a neuroinflammatory response consisting primarily of monocytes/macrophages. Microglia depletion via administration of colony-stimulating factor 1 receptor inhibitor, PLX5622, in SARS-CoV-2 infected mice did not affect survival or viral replication but did result in dampened expression of proinflammatory cytokine/chemokine transcripts and a reduction in monocyte/macrophage infiltration. These results argue that microglia are dispensable in terms of controlling SARS-CoV-2 replication in in the K18-hACE2 model but do contribute to an inflammatory response through expression of pro-inflammatory genes. Collectively, these findings contribute to previous work demonstrating the ability of SARS-CoV-2 to infect neurons as well as emphasizing the potential use of the K18-hACE2 model to study immunological and neuropathological aspects related to SARS-CoV-2-induced neurologic disease.

5.
ACS Infect Dis ; 7(8): 2229-2237, 2021 08 13.
Article in English | MEDLINE | ID: covidwho-1337099

ABSTRACT

SARS-CoV-2 virus has recently given rise to the current COVID-19 pandemic where infected individuals can range from being asymptomatic, yet highly contagious, to dying from acute respiratory distress syndrome. Although the world has mobilized to create antiviral vaccines and therapeutics to combat the scourge, their long-term efficacy remains in question especially with the emergence of new variants. In this work, we exploit a class of compounds that has previously shown success against various viruses. A salicylanilide library was first screened in a SARS-CoV-2 activity assay in Vero cells. The most efficacious derivative was further evaluated in a prophylactic mouse model of SARS-CoV-2 infection unveiling a salicylanilide that can reduce viral loads, modulate key cytokines, and mitigate severe weight loss involved in COVID-19 infections. The combination of anti-SARS-CoV-2 activity, cytokine inhibitory activity, and a previously established favorable pharmacokinetic profile for the lead salicylanilide renders salicylanilides in general as promising therapeutics for COVID-19.


Subject(s)
COVID-19 , Pandemics , Animals , Chlorocebus aethiops , Cytokines , Humans , Mice , Rodentia , SARS-CoV-2 , Salicylanilides , Vero Cells
6.
Immunity ; 54(7): 1463-1477.e11, 2021 07 13.
Article in English | MEDLINE | ID: covidwho-1263294

ABSTRACT

Acute respiratory distress syndrome (ARDS), an inflammatory condition with high mortality rates, is common in severe COVID-19, whose risk is reduced by metformin rather than other anti-diabetic medications. Detecting of inflammasome assembly in post-mortem COVID-19 lungs, we asked whether and how metformin inhibits inflammasome activation while exerting its anti-inflammatory effect. We show that metformin inhibited NLRP3 inflammasome activation and interleukin (IL)-1ß production in cultured and alveolar macrophages along with inflammasome-independent IL-6 secretion, thus attenuating lipopolysaccharide (LPS)- and SARS-CoV-2-induced ARDS. By targeting electron transport chain complex 1 and independently of AMP-activated protein kinase (AMPK) or NF-κB, metformin blocked LPS-induced and ATP-dependent mitochondrial (mt) DNA synthesis and generation of oxidized mtDNA, an NLRP3 ligand. Myeloid-specific ablation of LPS-induced cytidine monophosphate kinase 2 (CMPK2), which is rate limiting for mtDNA synthesis, reduced ARDS severity without a direct effect on IL-6. Thus, inhibition of ATP and mtDNA synthesis is sufficient for ARDS amelioration.


Subject(s)
Adenosine Triphosphate/metabolism , DNA, Mitochondrial/biosynthesis , Inflammasomes/drug effects , Metformin/pharmacology , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Pneumonia/prevention & control , Animals , COVID-19/metabolism , COVID-19/prevention & control , Cytokines/genetics , Cytokines/metabolism , DNA, Mitochondrial/metabolism , Humans , Inflammasomes/metabolism , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Lipopolysaccharides/toxicity , Metformin/therapeutic use , Mice , Nucleoside-Phosphate Kinase/metabolism , Pneumonia/metabolism , Respiratory Distress Syndrome/chemically induced , Respiratory Distress Syndrome/prevention & control , SARS-CoV-2/pathogenicity
7.
Nat Commun ; 12(1): 3309, 2021 06 03.
Article in English | MEDLINE | ID: covidwho-1260940

ABSTRACT

The ongoing pandemic caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), necessitates strategies to identify prophylactic and therapeutic drug candidates for rapid clinical deployment. Here, we describe a screening pipeline for the discovery of efficacious SARS-CoV-2 inhibitors. We screen a best-in-class drug repurposing library, ReFRAME, against two high-throughput, high-content imaging infection assays: one using HeLa cells expressing SARS-CoV-2 receptor ACE2 and the other using lung epithelial Calu-3 cells. From nearly 12,000 compounds, we identify 49 (in HeLa-ACE2) and 41 (in Calu-3) compounds capable of selectively inhibiting SARS-CoV-2 replication. Notably, most screen hits are cell-line specific, likely due to different virus entry mechanisms or host cell-specific sensitivities to modulators. Among these promising hits, the antivirals nelfinavir and the parent of prodrug MK-4482 possess desirable in vitro activity, pharmacokinetic and human safety profiles, and both reduce SARS-CoV-2 replication in an orthogonal human differentiated primary cell model. Furthermore, MK-4482 effectively blocks SARS-CoV-2 infection in a hamster model. Overall, we identify direct-acting antivirals as the most promising compounds for drug repurposing, additional compounds that may have value in combination therapies, and tool compounds for identification of viral host cell targets.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Drug Repositioning/methods , Pandemics , SARS-CoV-2 , Animals , COVID-19/prevention & control , COVID-19/virology , Cell Line , Cytidine/administration & dosage , Cytidine/analogs & derivatives , Cytidine/pharmacology , Databases, Pharmaceutical , Drug Discovery/methods , Drug Evaluation, Preclinical/methods , HeLa Cells , High-Throughput Screening Assays/methods , Humans , Hydroxylamines/administration & dosage , Hydroxylamines/pharmacology , Mesocricetus , Nelfinavir/pharmacology , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Virus Replication/drug effects
8.
Cell Rep ; 35(6): 109109, 2021 05 11.
Article in English | MEDLINE | ID: covidwho-1201425

ABSTRACT

It is unclear whether individuals with enormous diversity in B cell receptor repertoires are consistently able to mount effective antibody responses against SARS-CoV-2. We analyzed antibody responses in a cohort of 55 convalescent patients and isolated 54 potent neutralizing monoclonal antibodies (mAbs). While most of the mAbs target the angiotensin-converting enzyme 2 (ACE2) binding surface on the receptor binding domain (RBD) of SARS-CoV-2 spike protein, mAb 47D1 binds only to one side of the receptor binding surface on the RBD. Neutralization by 47D1 is achieved independent of interfering RBD-ACE2 binding. A crystal structure of the mAb-RBD complex shows that the IF motif at the tip of 47D1 CDR H2 interacts with a hydrophobic pocket in the RBD. Diverse immunoglobulin gene usage and convergent epitope targeting characterize neutralizing antibody responses to SARS-CoV-2, suggesting that vaccines that effectively present the receptor binding site on the RBD will likely elicit neutralizing antibody responses in a large fraction of the population.


Subject(s)
Antibodies, Neutralizing/genetics , COVID-19/genetics , Immunoglobulins/genetics , Adult , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Binding Sites/immunology , COVID-19/immunology , COVID-19/therapy , Epitopes/genetics , Epitopes/immunology , Female , Genes, Immunoglobulin/genetics , Genetic Variation/genetics , Humans , Immunization, Passive/methods , Immunoglobulins/immunology , Male , Middle Aged , Peptidyl-Dipeptidase A/metabolism , Protein Binding/immunology , Protein Domains/genetics , Receptors, Virus/immunology , Receptors, Virus/metabolism , SARS-CoV-2/genetics , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity
10.
Nat Rev Immunol ; 20(8): 507-514, 2020 08.
Article in English | MEDLINE | ID: covidwho-613021

ABSTRACT

Therapeutics against coronavirus disease 2019 (COVID-19) are urgently needed. Granulocyte-macrophage colony-stimulating factor (GM-CSF), a myelopoietic growth factor and pro-inflammatory cytokine, plays a critical role in alveolar macrophage homeostasis, lung inflammation and immunological disease. Both administration and inhibition of GM-CSF are currently being therapeutically tested in COVID-19 clinical trials. This Perspective discusses the pleiotropic biology of GM-CSF and the scientific merits behind these contrasting approaches.


Subject(s)
Betacoronavirus/drug effects , Coronavirus Infections/drug therapy , Granulocyte-Macrophage Colony-Stimulating Factor/therapeutic use , Pneumonia, Viral/drug therapy , COVID-19 , Clinical Trials as Topic , Humans , Pandemics , SARS-CoV-2
11.
Science ; 369(6506): 956-963, 2020 08 21.
Article in English | MEDLINE | ID: covidwho-599034

ABSTRACT

Countermeasures to prevent and treat coronavirus disease 2019 (COVID-19) are a global health priority. We enrolled a cohort of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-recovered participants, developed neutralization assays to investigate antibody responses, adapted our high-throughput antibody generation pipeline to rapidly screen more than 1800 antibodies, and established an animal model to test protection. We isolated potent neutralizing antibodies (nAbs) to two epitopes on the receptor binding domain (RBD) and to distinct non-RBD epitopes on the spike (S) protein. As indicated by maintained weight and low lung viral titers in treated animals, the passive transfer of a nAb provides protection against disease in high-dose SARS-CoV-2 challenge in Syrian hamsters. The study suggests a role for nAbs in prophylaxis, and potentially therapy, of COVID-19. The nAbs also define protective epitopes to guide vaccine design.


Subject(s)
Antibodies, Monoclonal , Antibodies, Neutralizing , Antibodies, Viral , Betacoronavirus/immunology , Coronavirus Infections/immunology , Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/immunology , Pneumonia, Viral/prevention & control , Adult , Angiotensin-Converting Enzyme 2 , Animals , Antibodies, Monoclonal/blood , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/isolation & purification , Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/isolation & purification , Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/blood , Antibodies, Viral/immunology , Antibodies, Viral/isolation & purification , Antibodies, Viral/therapeutic use , Antibody Affinity , Antibody Specificity , Betacoronavirus/physiology , Binding Sites , COVID-19 , Cell Line , Coronavirus Infections/therapy , Coronavirus Infections/virology , Disease Models, Animal , Epitopes , Female , Humans , Immunization, Passive , Lung/virology , Male , Mesocricetus , Middle Aged , Neutralization Tests , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/therapy , Pneumonia, Viral/virology , Protein Domains , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism , Viral Load , Virus Replication
SELECTION OF CITATIONS
SEARCH DETAIL