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1.
J Virol ; 96(9): e0003822, 2022 05 11.
Article in English | MEDLINE | ID: covidwho-1788914

ABSTRACT

Due to the limitation of human studies with respect to individual difference or the accessibility of fresh tissue samples, how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection results in pathological complications in lung, the main site of infection, is still incompletely understood. Therefore, physiologically relevant animal models under realistic SARS-CoV-2 infection conditions would be helpful to our understanding of dysregulated inflammation response in lung in the context of targeted therapeutics. Here, we characterized the single-cell landscape in lung and spleen upon SARS-CoV-2 infection in an acute severe disease mouse model that replicates human symptoms, including severe lung pathology and lymphopenia. We showed a reduction of lymphocyte populations and an increase of neutrophils in lung and then demonstrated the key role of neutrophil-mediated lung immunopathology in both mice and humans. Under severe conditions, neutrophils recruited by a chemokine-driven positive feedback produced elevated "fatal signature" proinflammatory genes and pathways related to neutrophil activation or releasing of granular content. In addition, we identified a new Cd177high cluster that is undergoing respiratory burst and Stfahigh cluster cells that may dampen antigen presentation upon infection. We also revealed the devastating effect of overactivated neutrophil by showing the highly enriched neutrophil extracellular traps in lung and a dampened B-cell function in either lung or spleen that may be attributed to arginine consumption by neutrophil. The current study helped our understanding of SARS-CoV-2-induced pneumonia and warranted the concept of neutrophil-targeting therapeutics in COVID-19 treatment. IMPORTANCE We demonstrated the single-cell landscape in lung and spleen upon SARS-CoV-2 infection in an acute severe disease mouse model that replicated human symptoms, including severe lung pathology and lymphopenia. Our comprehensive study revealed the key role of neutrophil-mediated lung immunopathology in SARS-CoV-2-induced severe pneumonia, which not only helped our understanding of COVID-19 but also warranted the concept of neutrophil targeting therapeutics in COVID-19 treatment.


Subject(s)
COVID-19 , Lung , Neutrophils , Animals , COVID-19/immunology , Disease Models, Animal , Humans , Lung/pathology , Lung/virology , Lymphopenia/virology , Mice , Neutrophils/immunology , SARS-CoV-2 , Spleen/pathology , Spleen/virology
2.
J Virol ; 96(8): e0016922, 2022 04 27.
Article in English | MEDLINE | ID: covidwho-1765080

ABSTRACT

Severe acute respiratory syndrome coronavirus (SARS-CoV-1) and SARS-CoV-2 are highly pathogenic to humans and have caused pandemics in 2003 and 2019, respectively. Genetically diverse SARS-related coronaviruses (SARSr-CoVs) have been detected or isolated from bats, and some of these viruses have been demonstrated to utilize human angiotensin-converting enzyme 2 (ACE2) as a receptor and to have the potential to spill over to humans. A pan-sarbecovirus vaccine that provides protection against SARSr-CoV infection is urgently needed. In this study, we evaluated the protective efficacy of an inactivated SARS-CoV-2 vaccine against recombinant SARSr-CoVs carrying two different spike proteins (named rWIV1 and rRsSHC014S, respectively). Although serum neutralizing assays showed limited cross-reactivity between the three viruses, the inactivated SARS-CoV-2 vaccine provided full protection against SARS-CoV-2 and rWIV1 and partial protection against rRsSHC014S infection in human ACE2 transgenic mice. Passive transfer of SARS-CoV-2-vaccinated mouse sera provided low protection for rWIV1 but not for rRsSHC014S infection in human ACE2 mice. A specific cellular immune response induced by WIV1 membrane protein peptides was detected in the vaccinated animals, which may explain the cross-protection of the inactivated vaccine. This study shows the possibility of developing a pan-sarbecovirus vaccine against SARSr-CoVs for future preparedness. IMPORTANCE The genetic diversity of SARSr-CoVs in wildlife and their potential risk of cross-species infection highlight the necessity of developing wide-spectrum vaccines against infection of various SARSr-CoVs. In this study, we tested the protective efficacy of the SARS-CoV-2 inactivated vaccine (IAV) against two SARSr-CoVs with different spike proteins in human ACE2 transgenic mice. We demonstrate that the SARS-CoV-2 IAV provides full protection against rWIV1 and partial protection against rRsSHC014S. The T-cell response stimulated by the M protein may account for the cross protection against heterogeneous SARSr-CoVs. Our findings suggest the feasibility of the development of pan-sarbecovirus vaccines, which can be a strategy of preparedness for future outbreaks caused by novel SARSr-CoVs from wildlife.


Subject(s)
COVID-19 Vaccines , Coronavirus Infections , Cross Protection , Spike Glycoprotein, Coronavirus , Vaccines, Inactivated , Angiotensin-Converting Enzyme 2/genetics , Animals , COVID-19/prevention & control , COVID-19 Vaccines/immunology , Chiroptera , Coronavirus Infections/immunology , Coronavirus Infections/prevention & control , Cross Protection/immunology , Humans , Mice , Mice, Transgenic , SARS Virus/genetics , SARS Virus/metabolism , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Vaccines, Inactivated/immunology , Viral Zoonoses/prevention & control
3.
Signal Transduct Target Ther ; 7(1): 83, 2022 03 11.
Article in English | MEDLINE | ID: covidwho-1740428

ABSTRACT

SARS-CoV-2 induced marked lymphopenia in severe patients with COVID-19. However, whether lymphocytes are targets of viral infection is yet to be determined, although SARS-CoV-2 RNA or antigen has been identified in T cells from patients. Here, we confirmed that SARS-CoV-2 viral antigen could be detected in patient peripheral blood cells (PBCs) or postmortem lung T cells, and the infectious virus could also be detected from viral antigen-positive PBCs. We next prove that SARS-CoV-2 infects T lymphocytes, preferably activated CD4 + T cells in vitro. Upon infection, viral RNA, subgenomic RNA, viral protein or viral particle can be detected in the T cells. Furthermore, we show that the infection is spike-ACE2/TMPRSS2-independent through using ACE2 knockdown or receptor blocking experiments. Next, we demonstrate that viral antigen-positive T cells from patient undergone pronounced apoptosis. In vitro infection of T cells induced cell death that is likely in mitochondria ROS-HIF-1a-dependent pathways. Finally, we demonstrated that LFA-1, the protein exclusively expresses in multiple leukocytes, is more likely the entry molecule that mediated SARS-CoV-2 infection in T cells, compared to a list of other known receptors. Collectively, this work confirmed a SARS-CoV-2 infection of T cells, in a spike-ACE2-independent manner, which shed novel insights into the underlying mechanisms of SARS-CoV-2-induced lymphopenia in COVID-19 patients.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/metabolism , SARS-CoV-2/metabolism , T-Lymphocytes/metabolism , Animals , Caco-2 Cells , Chlorocebus aethiops , Humans , Vero Cells
5.
Viruses ; 13(12)2021 12 11.
Article in English | MEDLINE | ID: covidwho-1572660

ABSTRACT

Patients with COVID-19 generally raise antibodies against SARS-CoV-2 following infection, and the antibody level is positively correlated to the severity of disease. Whether the viral antibodies exacerbate COVID-19 through antibody-dependent enhancement (ADE) is still not fully understood. Here, we conducted in vitro assessment of whether convalescent serum enhanced SARS-CoV-2 infection or induced excessive immune responses in immune cells. Our data revealed that SARS-CoV-2 infection of primary B cells, macrophages and monocytes, which express variable levels of FcγR, could be enhanced by convalescent serum from COVID-19 patients. We also determined the factors associated with ADE, and found which showed a time-dependent but not viral-dose dependent manner. Furthermore, the ADE effect is not associated with the neutralizing titer or RBD antibody level when testing serum samples collected from different patients. However, it is higher in a medium level than low or high dilutions in a given sample that showed ADE effect, which is similar to dengue. Finally, we demonstrated more viral genes or dysregulated host immune gene expression under ADE conditions compared to the no-serum infection group. Collectively, our study provides insight into the understanding of an association of high viral antibody titer and severe lung pathology in severe patients with COVID-19.


Subject(s)
Antibody-Dependent Enhancement/immunology , Leukocytes/virology , SARS-CoV-2/pathogenicity , COVID-19/immunology , Cells, Cultured , Gene Expression Profiling , Humans , Immune Sera/immunology , Leukocytes/metabolism , Receptors, IgG/metabolism , Virus Replication/immunology
6.
mBio ; 12(5): e0234221, 2021 10 26.
Article in English | MEDLINE | ID: covidwho-1494971

ABSTRACT

The recent emergence and spread of zoonotic viruses highlights that animal-sourced viruses are the biggest threat to global public health. Swine acute diarrhea syndrome coronavirus (SADS-CoV) is an HKU2-related bat coronavirus that was spilled over from Rhinolophus bats to swine, causing large-scale outbreaks of severe diarrhea disease in piglets in China. Unlike other porcine coronaviruses, SADS-CoV possesses broad species tissue tropism, including primary human cells, implying a significant risk of cross-species spillover. To explore host dependency factors for SADS-CoV as therapeutic targets, we employed genome-wide CRISPR knockout library screening in HeLa cells. Consistent with two independent screens, we identified the zinc finger DHHC-type palmitoyltransferase 17 (ZDHHC17 or ZD17) as an important host factor for SADS-CoV infection. Through truncation mutagenesis, we demonstrated that the DHHC domain of ZD17 that is involved in palmitoylation is important for SADS-CoV infection. Mechanistic studies revealed that ZD17 is required for SADS-CoV genomic RNA replication. Treatment of infected cells with the palmitoylation inhibitor 2-bromopalmitate (2-BP) significantly suppressed SADS-CoV infection. Our findings provide insight on SADS-CoV-host interactions and a potential therapeutic application. IMPORTANCE The recent emergence of deadly zoonotic viral diseases, including Ebola virus and SARS-CoV-2, emphasizes the importance of pandemic preparedness for the animal-sourced viruses with potential risk of animal-to-human spillover. Over the last 2 decades, three significant coronaviruses of bat origin, SARS-CoV, MERS-CoV, and SARS-CoV-2, have caused millions of deaths with significant economy and public health impacts. Lack of effective therapeutics against these coronaviruses was one of the contributing factors to such losses. Although SADS-CoV, another coronavirus of bat origin, was only known to cause fatal diarrhea disease in piglets, the ability to infect cells derived from multiple species, including human, highlights the potential risk of animal-to-human spillover. As part of our effort in pandemic preparedness, we explore SADS-CoV host dependency factors as targets for host-directed therapeutic development and found zinc finger DHHC-type palmitoyltransferase 17 is a promising drug target against SADS-CoV replication. We also demonstrated that a palmitoylation inhibitor, 2-bromopalmitate (2-BP), can be used as an inhibitor for SADS-CoV treatment.


Subject(s)
Acyltransferases/metabolism , Adaptor Proteins, Signal Transducing/metabolism , Alphacoronavirus/pathogenicity , Nerve Tissue Proteins/metabolism , Acyltransferases/genetics , Adaptor Proteins, Signal Transducing/genetics , Alphacoronavirus/drug effects , Animals , COVID-19/metabolism , HeLa Cells , Humans , Middle East Respiratory Syndrome Coronavirus/drug effects , Middle East Respiratory Syndrome Coronavirus/pathogenicity , Nerve Tissue Proteins/genetics , Palmitates/pharmacology , SARS Virus/drug effects , SARS Virus/pathogenicity , SARS-CoV-2/drug effects , SARS-CoV-2/pathogenicity , Swine
9.
Virol Sin ; 36(5): 879-889, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1174014

ABSTRACT

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused more than 96 million infections and over 2 million deaths worldwide so far. However, there is no approved vaccine available for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the disease causative agent. Vaccine is the most effective approach to eradicate a pathogen. The tests of safety and efficacy in animals are pivotal for developing a vaccine and before the vaccine is applied to human populations. Here we evaluated the safety, immunogenicity, and efficacy of an inactivated vaccine based on the whole viral particles in human ACE2 transgenic mouse and in non-human primates. Our data showed that the inactivated vaccine successfully induced SARS-CoV-2-specific neutralizing antibodies in mice and non-human primates, and subsequently provided partial (in low dose) or full (in high dose) protection of challenge in the tested animals. In addition, passive serum transferred from vaccine-immunized mice could also provide full protection from SARS-CoV-2 infection in mice. These results warranted positive outcomes in future clinical trials in humans.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19 , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/prevention & control , Mice , Mice, Transgenic , Primates , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Vaccines, Inactivated/immunology
11.
Cell ; 182(1): 50-58.e8, 2020 07 09.
Article in English | MEDLINE | ID: covidwho-343611

ABSTRACT

COVID-19 has spread worldwide since 2019 and is now a severe threat to public health. We previously identified the causative agent as a novel SARS-related coronavirus (SARS-CoV-2) that uses human angiotensin-converting enzyme 2 (hACE2) as the entry receptor. Here, we successfully developed a SARS-CoV-2 hACE2 transgenic mouse (HFH4-hACE2 in C3B6 mice) infection model. The infected mice generated typical interstitial pneumonia and pathology that were similar to those of COVID-19 patients. Viral quantification revealed the lungs as the major site of infection, although viral RNA could also be found in the eye, heart, and brain in some mice. Virus identical to SARS-CoV-2 in full-genome sequences was isolated from the infected lung and brain tissues. Last, we showed that pre-exposure to SARS-CoV-2 could protect mice from severe pneumonia. Our results show that the hACE2 mouse would be a valuable tool for testing potential vaccines and therapeutics.


Subject(s)
Betacoronavirus/physiology , Coronavirus Infections/pathology , Disease Models, Animal , Mice, Transgenic , Pneumonia, Viral/pathology , Angiotensin-Converting Enzyme 2 , Animals , COVID-19 , Female , Humans , Lung Diseases, Interstitial/pathology , Lung Diseases, Interstitial/virology , Male , Mice , Mice, Inbred C3H , Mice, Inbred C57BL , Mice, Transgenic/genetics , Pandemics , Peptidyl-Dipeptidase A/genetics , SARS-CoV-2 , Viral Tropism , Weight Loss
12.
Nature ; 579(7798): 270-273, 2020 03.
Article in English | MEDLINE | ID: covidwho-246

ABSTRACT

Since the outbreak of severe acute respiratory syndrome (SARS) 18 years ago, a large number of SARS-related coronaviruses (SARSr-CoVs) have been discovered in their natural reservoir host, bats1-4. Previous studies have shown that some bat SARSr-CoVs have the potential to infect humans5-7. Here we report the identification and characterization of a new coronavirus (2019-nCoV), which caused an epidemic of acute respiratory syndrome in humans in Wuhan, China. The epidemic, which started on 12 December 2019, had caused 2,794 laboratory-confirmed infections including 80 deaths by 26 January 2020. Full-length genome sequences were obtained from five patients at an early stage of the outbreak. The sequences are almost identical and share 79.6% sequence identity to SARS-CoV. Furthermore, we show that 2019-nCoV is 96% identical at the whole-genome level to a bat coronavirus. Pairwise protein sequence analysis of seven conserved non-structural proteins domains show that this virus belongs to the species of SARSr-CoV. In addition, 2019-nCoV virus isolated from the bronchoalveolar lavage fluid of a critically ill patient could be neutralized by sera from several patients. Notably, we confirmed that 2019-nCoV uses the same cell entry receptor-angiotensin converting enzyme II (ACE2)-as SARS-CoV.


Subject(s)
Betacoronavirus/classification , Betacoronavirus/genetics , Chiroptera/virology , Coronavirus Infections/epidemiology , Coronavirus Infections/virology , Disease Outbreaks , Pneumonia, Viral/epidemiology , Pneumonia, Viral/virology , Angiotensin-Converting Enzyme 2 , Animals , Antibodies, Viral/blood , Betacoronavirus/metabolism , Betacoronavirus/ultrastructure , COVID-19 , Cell Line , China/epidemiology , Chlorocebus aethiops , Female , Genome, Viral/genetics , Humans , Male , Peptidyl-Dipeptidase A/metabolism , Phylogeny , SARS Virus/classification , SARS Virus/genetics , SARS-CoV-2 , Sequence Homology, Nucleic Acid , Severe Acute Respiratory Syndrome , Vero Cells
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