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1.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-325339

ABSTRACT

SARS-CoV-2 is more infectious and transmissible in humans than SARS-CoV, despite the genetic relatedness and sharing the same cellular receptor. We sought to assess whether human airway organoids can model SARS-CoV-2 infection in the human airway and elucidate the cellular basis underlying its higher transmissibility. We demonstrate that SARS-CoV-2 can establish a productive infection in human airway organoids, in which ciliated cell and basal cell are infected. Wildtype SARS-CoV-2 carrying a furin cleavage motif exhibits comparable replication kinetics to a mutant virus without the motif. Human airway organoids sustain higher replication of SARS-CoV-2 than SARS-CoV, whereas interferon response is more potently induced in the latter than the former. Overall, human airway organoids can model SARS-CoV-2 infection and recapitulate the disposable role of furin cleavage motif for virus transmission in humans. SARS-CoV-2 stealth growth and evasion of interferon response may underlie pre-symptomatic virus shedding in COVID-19 patients, leading to its high infectiousness and transmissibility.

2.
J Immunol ; 206(11): 2527-2535, 2021 06 01.
Article in English | MEDLINE | ID: covidwho-1227097

ABSTRACT

The T cell response is an important detection index in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine development. The present study was undertaken to determine the T cell epitopes in the spike (S) protein of SARS-CoV-2 that dominate the T cell responses in SARS-CoV-2-infected patients. PBMCs from rhesus macaques vaccinated with a DNA vaccine encoding the full-length S protein were isolated, and an ELISPOT assay was used to identify the recognized T cell epitopes among a total of 158 18-mer and 10-aa-overlapping peptides spanning the full-length S protein. Six multipeptide-based epitopes located in the S1 region, with four of the six located in the receptor-binding domain, were defined as the most frequently recognized epitopes in macaques. The conservation of the epitopes across species was also verified, and peptide mixtures for T cell response detection were established. Six newly defined T cell epitopes were found in the current study, which may provide a novel potential target for T cell response detection and the diagnosis and vaccine design of SARS-CoV-2 based on multipeptide subunit-based epitopes.


Subject(s)
Epitopes, T-Lymphocyte/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Animals , Macaca mulatta
3.
Stem Cell Reports ; 16(3): 493-504, 2021 03 09.
Article in English | MEDLINE | ID: covidwho-1099264

ABSTRACT

Enteroviruses, such as EV-A71 and CVA16, mainly infect the human gastrointestinal tract. Human coronaviruses, including SARS-CoV and SARS-CoV-2, have been variably associated with gastrointestinal symptoms. We aimed to optimize the human intestinal organoids and hypothesize that these optimized intestinal organoids can recapitulate enteric infections of enterovirus and coronavirus. We demonstrate that the optimized human intestinal organoids enable better simulation of the native human intestinal epithelium, and that they are significantly more susceptible to EV-A71 than CVA16. Higher replication of EV-A71 than CVA16 in the intestinal organoids triggers a more vigorous cellular response. However, SARS-CoV and SARS-CoV-2 exhibit distinct dynamics of virus-host interaction; more robust propagation of SARS-CoV triggers minimal cellular response, whereas, SARS-CoV-2 exhibits lower replication capacity but elicits a moderate cellular response. Taken together, the disparate profile of the virus-host interaction of enteroviruses and coronaviruses in human intestinal organoids may unravel the cellular basis of the distinct pathogenicity of these viral pathogens.


Subject(s)
COVID-19/virology , Enterovirus A, Human/pathogenicity , Enterovirus Infections/virology , Intestines/virology , Organoids/virology , SARS-CoV-2/pathogenicity , Animals , Cell Line , Chlorocebus aethiops , Host Microbial Interactions/physiology , Humans , Intestinal Mucosa/virology , Vero Cells , Virus Replication/physiology
4.
Emerg Microbes Infect ; 10(1): 342-355, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1069193

ABSTRACT

The current study aims to develop a safe and highly immunogenic COVID-19 vaccine. The novel combination of a DNA vaccine encoding the full-length Spike (S) protein of SARS-CoV-2 and a recombinant S1 protein vaccine induced high level neutralizing antibody and T cell immune responses in both small and large animal models. More significantly, the co-delivery of DNA and protein components at the same time elicited full protection against intratracheal challenge of SARS-CoV-2 viruses in immunized rhesus macaques. As both DNA and protein vaccines have been proven safe in previous human studies, and DNA vaccines are capable of eliciting germinal center B cell development, which is critical for high-affinity memory B cell responses, the DNA and protein co-delivery vaccine approach has great potential to serve as a safe and effective approach to develop COVID-19 vaccines that provide long-term protection.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/prevention & control , Spike Glycoprotein, Coronavirus/immunology , Vaccines, DNA/immunology , Vaccines, Subunit/immunology , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Cell Line , DNA/immunology , HEK293 Cells , Humans , Lymphocyte Count , Macaca mulatta , Mice , Mice, Inbred C57BL , Plasmids/genetics , Rabbits , Recombinant Proteins/immunology , SARS-CoV-2/genetics , SARS-CoV-2/immunology , T-Lymphocytes/immunology
5.
Emerg Microbes Infect ; 9(1): 2663-2672, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-919316

ABSTRACT

Rapid accumulation of viral proteins in host cells render viruses highly dependent on cellular chaperones including heat shock protein 90 (Hsp90). Three highly pathogenic human coronaviruses, including MERS-CoV, SARS-CoV and SARS-CoV-2, have emerged in the past 2 decades. However, there is no approved antiviral agent against these coronaviruses. We inspected the role of Hsp90 for coronavirus propagation. First, an Hsp90 inhibitor, 17-AAG, significantly suppressed MERS-CoV propagation in cell lines and physiological-relevant human intestinal organoids. Second, siRNA depletion of Hsp90ß, but not Hsp90α, significantly restricted MERS-CoV replication and abolished virus spread. Third, Hsp90ß interaction with MERS-CoV nucleoprotein (NP) was revealed in a co-immunoprecipitation assay. Hsp90ß is required to maintain NP stability. Fourth, 17-AAG substantially inhibited the propagation of SARS-CoV and SARS-CoV-2. Collectively, Hsp90 is a host dependency factor for human coronavirus MERS-CoV, SARS-CoV and SARS-COV-2. Hsp90 inhibitors can be repurposed as a potent and broad-spectrum antiviral against human coronaviruses.


Subject(s)
Antiviral Agents/pharmacology , Benzoquinones/pharmacology , HSP90 Heat-Shock Proteins/antagonists & inhibitors , HSP90 Heat-Shock Proteins/genetics , Host Microbial Interactions/drug effects , Lactams, Macrocyclic/pharmacology , Middle East Respiratory Syndrome Coronavirus/drug effects , A549 Cells , Animals , COVID-19/drug therapy , Cell Line , Chlorocebus aethiops , HEK293 Cells , Humans , Intestines/virology , Organ Culture Techniques , RNA, Small Interfering , SARS Virus/drug effects , SARS-CoV-2/drug effects , Vero Cells , Virus Replication/drug effects
6.
J Infect Dis ; 221(4): 647-659, 2020 02 03.
Article in English | MEDLINE | ID: covidwho-326851

ABSTRACT

BACKGROUND: Human infection with Middle East respiratory syndrome coronavirus (MERS-CoV) poses an ongoing threat to public health worldwide. The studies of MERS patients with severe disease and experimentally infected animals showed that robust viral replication and intensive proinflammatory response in lung tissues contribute to high pathogenicity of MERS-CoV. We sought to identify pattern recognition receptor (PRR) signaling pathway(s) that mediates the inflammatory cascade in human macrophages upon MERS-CoV infection. METHODS: The potential signaling pathways were manipulated individually by pharmacological inhibition, small interfering ribonucleic acid (siRNA) depletion, and antibody blocking. The MERS-CoV-induced proinflammatory response was evaluated by measuring the expression levels of key cytokines and/or chemokines. Reverse transcription-quantitative polymerase chain reaction assay, flow cytometry analysis, and Western blotting were applied to evaluate the activation of related PRRs and engagement of adaptors. RESULTS: MERS-CoV replication significantly upregulated C-type lectin receptor (CLR) macrophage-inducible Ca2+-dependent lectin receptor (Mincle). The role of Mincle for MERS-CoV-triggered cytokine/chemokine induction was established based on the results of antibody blockage, siRNA depletion of Mincle and its adaptor spleen tyrosine kinase (Syk), and Syk pharmacological inhibition. The cytokine and/or chemokine induction was significantly attenuated by siRNA depletion of retinoic acid-inducible-I-like receptors (RLR) or adaptor, indicating that RLR signaling also contributed to MERS-CoV-induced proinflammatory response. CONCLUSIONS: The CLR and RLR pathways are activated and contribute to the proinflammatory response in MERS-CoV-infected macrophages.


Subject(s)
Coronavirus Infections/immunology , DEAD Box Protein 58/metabolism , Lectins, C-Type/metabolism , Macrophages/immunology , Macrophages/virology , Middle East Respiratory Syndrome Coronavirus/metabolism , Animals , CARD Signaling Adaptor Proteins , Chemokines/metabolism , Chlorocebus aethiops , Coronavirus Infections/metabolism , Coronavirus Infections/virology , Cytokines/immunology , Cytokines/metabolism , DEAD Box Protein 58/genetics , Gene Knockdown Techniques , Humans , Lectins, C-Type/genetics , Lung/immunology , Middle East Respiratory Syndrome Coronavirus/genetics , Middle East Respiratory Syndrome Coronavirus/pathogenicity , RNA, Small Interfering/metabolism , Receptors, Immunologic/genetics , Receptors, Immunologic/metabolism , Signal Transduction , Transcriptome , Tretinoin/pharmacology , Vero Cells , Virus Replication
7.
Nat Med ; 26(7): 1077-1083, 2020 07.
Article in English | MEDLINE | ID: covidwho-260261

ABSTRACT

A novel coronavirus-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-emerged in humans in Wuhan, China, in December 2019 and has since disseminated globally1,2. As of April 16, 2020, the confirmed case count of coronavirus disease 2019 (COVID-19) had surpassed 2 million. Based on full-genome sequence analysis, SARS-CoV-2 shows high homology to SARS-related coronaviruses identified in horseshoe bats1,2. Here we show the establishment and characterization of expandable intestinal organoids derived from horseshoe bats of the Rhinolophus sinicus species that can recapitulate bat intestinal epithelium. These bat enteroids are fully susceptible to SARS-CoV-2 infection and sustain robust viral replication. Development of gastrointestinal symptoms in some patients with COVID-19 and detection of viral RNA in fecal specimens suggest that SARS-CoV-2 might cause enteric, in addition to respiratory, infection3,4. Here we demonstrate active replication of SARS-CoV-2 in human intestinal organoids and isolation of infectious virus from the stool specimen of a patient with diarrheal COVID-19. Collectively, we established the first expandable organoid culture system of bat intestinal epithelium and present evidence that SARS-CoV-2 can infect bat intestinal cells. The robust SARS-CoV-2 replication in human intestinal organoids suggests that the human intestinal tract might be a transmission route of SARS-CoV-2.


Subject(s)
Betacoronavirus/pathogenicity , Coronavirus Infections/pathology , Coronavirus Infections/transmission , Intestines/virology , Organoids/virology , Pneumonia, Viral/pathology , Pneumonia, Viral/transmission , Animals , COVID-19 , Cell Differentiation , Cells, Cultured , Child, Preschool , Chiroptera/virology , Chlorocebus aethiops , Coronavirus Infections/virology , Enterocytes/pathology , Enterocytes/physiology , Enterocytes/virology , Female , Humans , Infant , Intestinal Mucosa/pathology , Intestinal Mucosa/virology , Intestines/pathology , Male , Organoids/pathology , Pandemics , Pneumonia, Viral/virology , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2 , Vero Cells , Viral Load/genetics , Viral Load/methods , Viral Tropism/physiology
8.
J Med Virol ; 92(9): 1609-1614, 2020 09.
Article in English | MEDLINE | ID: covidwho-46751

ABSTRACT

Since the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in humans in late 2019, it has rapidly spread worldwide. To identify the biological characteristics of SARS-CoV-2 in a normal laboratory environment (biosafety level 2 [BSL-2]), a lentiviral-based nucleocapsid was used to carry the spike protein of SARS-CoV-2 onto the surface of pseudoviral particles as a surrogate model to evaluate the infective characterization of SARS-CoV-2. This study indicated that SARS-CoV-2 has extensive tissue tropism for humans and may infect monkeys and tree shrews but not rodents. More importantly, the use of pseudoviral particles in this study allows rapid assessment of neutralizing antibodies in serum in a BSL-2 laboratory. This study will provide a quick and easy tool for evaluating neutralizing antibodies in the serum of recovering patients and assessing the potency of candidate vaccines.


Subject(s)
COVID-19/virology , Genetic Engineering , Recombination, Genetic , SARS-CoV-2/genetics , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , COVID-19/prevention & control , Cell Line , Cells, Cultured , Genes, Reporter , Humans , Neutralization Tests , Organ Specificity , SARS-CoV-2/physiology , Species Specificity , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Transduction, Genetic , Viral Vaccines , Virion/genetics
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