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1.
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
2.
Front Pharmacol ; 12: 735223, 2021.
Article in English | MEDLINE | ID: covidwho-1551527

ABSTRACT

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne virus causing serious infectious disease with a high case-fatality of up to 50% in severe cases. Currently, no effective drug has been approved for the treatment of SFTSV infection. Here, we performed a high-throughput screening of a natural extracts library for compounds with activities against SFTSV infection. Three hit compounds, notoginsenoside Ft1, punicalin, and toosendanin were identified for displaying high anti-SFTSV efficacy, in which, toosendanin showed the highest inhibition potency. Mechanistic investigation indicated that toosendanin inhibited SFTSV infection at the step of virus internalization. The anti-viral effect of toosendanin against SFTSV was further verified in mouse infection models, and the treatment with toosendanin significantly reduced viral load and histopathological changes in vivo. The antiviral activity of toosendanin was further expanded to another bunyavirus and the emerging SARS-CoV-2. This study revealed a broad anti-viral effect of toosendanin and indicated its potential to be developed as an anti-viral drug for clinical use.

3.
Front Immunol ; 12: 750969, 2021.
Article in English | MEDLINE | ID: covidwho-1551506

ABSTRACT

The COVID-19 is an infectious disease caused by SARS-CoV-2 infection. A large number of clinical studies found high-level expression of pro-inflammatory cytokines in patients infected with SARS-CoV-2, which fuels the rapid development of the disease. However, the specific molecular mechanism is still unclear. In this study, we found that SARS-CoV-2 Nsp5 can induce the expression of cytokines IL-1ß, IL-6, TNF-α, and IL-2 in Calu-3 and THP1 cells. Further research found that Nsp5 enhances cytokine expression through activating the NF-κB signaling pathway. Subsequently, we investigated the upstream effectors of the NF-κB signal pathway on Nsp5 overexpression and discovered that Nsp5 increases the protein level of MAVS. Moreover, Nsp5 can promote the SUMOylation of MAVS to increase its stability and lead to increasing levels of MAVS protein, finally triggering activation of NF-κB signaling. The knockdown of MAVS and the inhibitor of SUMOylation treatment can attenuate Nsp5-mediated NF-κB activation and cytokine induction. We identified a novel role of SARS-CoV-2 Nsp5 to enhance cytokine production by activating the NF-κB signaling pathway.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Coronavirus 3C Proteases/immunology , Cytokines/biosynthesis , NF-kappa B/metabolism , SARS-CoV-2/immunology , Sumoylation/physiology , Adaptor Proteins, Signal Transducing/genetics , Animals , COVID-19/immunology , Cell Line , Chlorocebus aethiops , Enzyme Activation/drug effects , HEK293 Cells , Humans , Immunity, Innate/immunology , Interleukin-1beta/biosynthesis , Interleukin-2/biosynthesis , Interleukin-6/biosynthesis , Signal Transduction/physiology , Sumoylation/drug effects , THP-1 Cells , Tumor Necrosis Factor-alpha/biosynthesis , Vero Cells
4.
ACS Infect Dis ; 7(6): 1409-1422, 2021 06 11.
Article in English | MEDLINE | ID: covidwho-1493008

ABSTRACT

Arenaviruses are a large family of enveloped negative-strand RNA viruses that include several causative agents of severe hemorrhagic fevers. Currently, there are no FDA-licensed drugs to treat arenavirus infection except for the off-labeled use of ribavirin. Here, we performed antiviral drug screening against the Old World arenavirus lymphocytic choriomeningitis virus (LCMV) using an FDA-approved drug library. Five drug candidates were identified, including mycophenolic acid, benidipine hydrochloride, clofazimine, dabrafenib, and apatinib, for having strong anti-LCMV effects. Further analysis indicated that benidipine hydrochloride inhibited LCMV membrane fusion, and an adaptive mutation on the LCMV glycoprotein D414 site was found to antagonize the anti-LCMV activity of benidipine hydrochloride. Mycophenolic acid inhibited LCMV replication by depleting GTP production. We also found mycophenolic acid, clofazimine, dabrafenib, and apatinib can inhibit the newly emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Owing to their FDA-approved status, these drug candidates can potentially be used rapidly in the clinical treatment of arenavirus and SARS-CoV-2 infection.


Subject(s)
COVID-19 , Pharmaceutical Preparations , High-Throughput Screening Assays , Humans , SARS-CoV-2 , Virus Replication
5.
Signal Transduct Target Ther ; 6(1): 346, 2021 09 24.
Article in English | MEDLINE | ID: covidwho-1437668

ABSTRACT

Antibody-dependent cellular cytotoxicity (ADCC) responses to viral infection are a form of antibody regulated immune responses mediated through the Fc fragment. Whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) triggered ADCC responses contributes to COVID-19 disease development is currently not well understood. To understand the potential correlation between ADCC responses and COVID-19 disease development, we analyzed the ADCC activity and neutralizing antibody response in 255 individuals ranging from asymptomatic to fatal infections over 1 year post disease. ADCC was elicited by 10 days post-infection, peaked by 11-20 days, and remained detectable until 400 days post-infection. In general, patients with severe disease had higher ADCC activities. Notably, patients who had severe disease and recovered had higher ADCC activities than patients who had severe disease and deceased. Importantly, ADCC activities were mediated by a diversity of epitopes in SARS-COV-2-infected mice and induced to comparable levels against SARS-CoV-2 variants of concern (VOCs) (B.1.1.7, B.1.351, and P.1) as that against the D614G mutant in human patients and vaccinated mice. Our study indicates anti-SARS-CoV-2 ADCC as a major trait of COVID-19 patients with various conditions, which can be applied to estimate the extra-neutralization level against COVID-19, especially lethal COVID-19.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Antibody-Dependent Cell Cytotoxicity , COVID-19/immunology , SARS-CoV-2/immunology , Adult , Aged , Animals , Cell Line, Tumor , Female , Humans , Male , Mice , Middle Aged
6.
Signal Transduct Target Ther ; 6(1): 181, 2021 05 10.
Article in English | MEDLINE | ID: covidwho-1223081

ABSTRACT

Over 40% of the coronavirus disease 2019 (COVID-19) COVID-19 patients were asymptomatically infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the immune responses of these asymptomatic individuals is a critical factor for developing the strategy to contain the COVID-19 pandemic. Here, we determined the viral dynamics and antibody responses among 143 asymptomatic individuals identified in a massive screening of more than 5 million people in eight districts of Wuhan in May 2020. Asymptomatic individuals were admitted to the government-designated centralized sites in accordance with policy. The incidence rate of asymptomatic infection is ~2.92/100,000. These individuals had low viral copy numbers (peaked at 315 copies/mL) and short-lived antibody responses with the estimated diminish time of 69 days. The antibody responses in individuals with persistent SARS-CoV-2 infection is much longer with the estimated diminish time of 257 days. These results imply that the immune responses in the asymptomatic individuals are not potent enough for preventing SARS-CoV-2 re-infection, which has recently been reported in recovered COVID-19 patients. This casts doubt on the efficacy of forming "herd-immunity" through natural SARS-CoV-2 infection and urges for the development of safe and effective vaccines.


Subject(s)
Antibodies, Viral/immunology , Asymptomatic Infections/epidemiology , COVID-19/immunology , Immunity/immunology , Aged , Antibodies, Viral/blood , Antibodies, Viral/genetics , COVID-19/blood , COVID-19/physiopathology , COVID-19/virology , China/epidemiology , Female , Humans , Male , Middle Aged , Pandemics , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity
8.
Biochem Biophys Res Commun ; 556: 87-92, 2021 06 04.
Article in English | MEDLINE | ID: covidwho-1173393

ABSTRACT

Virus-induced cytokine storm has been a devastating actuality in clinic. The abnormal production of type I interferon (IFN-1) and upregulation of multiple cytokines induced strong inflammation and thus lead to shock and organ failure. As an E3 ubiquitin ligase, tripartite motif-containing 37 (TRIM37) regulates the ubiquitination of multiple proteins including TRAFs. RNA sequencing was performed to investigated the alteration of transcriptional profile of H1N1-infected patients. qRT-PCR assay was performed to investigate the RNA levels of certain genes. The group of immune cells was examined by the Flow cytometry analysis. H&E staining was applied to evaluate lung inflammation of WT and TRIM37-KO mice. ELISA assay was performed to demonstrate the alteration of multiple cytokines. The protein levels in NF-kB signaling was estimated by western blotting and immunoprecipitation assays were applied to demonstrate the direct interaction between TRIM37 and TRAF-6. The RNA level of TRIM37 decreased in CD11b+ cells of Flu-infected patients. Knockout of TRIM37 inhibited the immune responses of H1N1-infected mice. TRIM37 deficiency reduced the levels of virous proinflammatory cytokines in bone marrow derived macrophages (BMDMs). Mechanically, TRIM37 promoted the K63-linked ubiquitination of TRAF6. TRIM37 negatively regulated inflammatory responses induced by virus infection via promoting TRAF6 ubiquitination at K63.


Subject(s)
Inflammation/metabolism , Orthomyxoviridae Infections/metabolism , Orthomyxoviridae Infections/virology , TNF Receptor-Associated Factor 6/metabolism , Tripartite Motif Proteins/metabolism , Ubiquitin-Protein Ligases/metabolism , Ubiquitination , Animals , Female , Humans , Inflammation Mediators/antagonists & inhibitors , Inflammation Mediators/immunology , Influenza A Virus, H1N1 Subtype/immunology , Influenza, Human/genetics , Influenza, Human/immunology , Influenza, Human/metabolism , Influenza, Human/virology , Mice , Mice, Inbred C57BL , Orthomyxoviridae Infections/genetics , Orthomyxoviridae Infections/immunology , TNF Receptor-Associated Factor 6/chemistry , Tripartite Motif Proteins/deficiency , Tripartite Motif Proteins/genetics , Ubiquitin-Protein Ligases/deficiency , Ubiquitin-Protein Ligases/genetics
9.
Cell Discov ; 6(1): 96, 2020 Dec 22.
Article in English | MEDLINE | ID: covidwho-989763

ABSTRACT

The coronavirus disease (COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has now spread to >200 countries posing a global public health concern. Patients with comorbidity, such as hypertension suffer more severe infection with elevated mortality. The development of effective antiviral drugs is in urgent need to treat COVID-19 patients. Here, we report that calcium channel blockers (CCBs), a type of antihypertensive drug that is widely used in clinics, inhibited the post-entry replication events of SARS-CoV-2 in vitro, while no in vitro anti-SARS-CoV-2 effect was observed for the two other major types of antihypertensive drugs, namely, angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers. CCB combined with chloroquine showed a significantly enhanced anti-SARS-CoV-2 efficacy. A retrospective clinical investigation on hospitalized COVID-19 patients with hypertension as the only comorbidity revealed that the CCB amlodipine besylate therapy was associated with a decreased case fatality rate. The results from this study suggest that CCB administration to COVID-19 patients with hypertension as the comorbidity might improve the disease outcome.

10.
Signal Transduct Target Ther ; 5(1): 235, 2020 10 09.
Article in English | MEDLINE | ID: covidwho-841900

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can lead to respiratory illness and multi-organ failure in critically ill patients. Although the virus-induced lung damage and inflammatory cytokine storm are believed to be directly associated with coronavirus disease 2019 (COVID-19) clinical manifestations, the underlying mechanisms of virus-triggered inflammatory responses are currently unknown. Here we report that SARS-CoV-2 infection activates caspase-8 to trigger cell apoptosis and inflammatory cytokine processing in the lung epithelial cells. The processed inflammatory cytokines are released through the virus-induced necroptosis pathway. Virus-induced apoptosis, necroptosis, and inflammation activation were also observed in the lung sections of SARS-CoV-2-infected HFH4-hACE2 transgenic mouse model, a valid model for studying SARS-CoV-2 pathogenesis. Furthermore, analysis of the postmortem lung sections of fatal COVID-19 patients revealed not only apoptosis and necroptosis but also massive inflammatory cell infiltration, necrotic cell debris, and pulmonary interstitial fibrosis, typical of immune pathogenesis in the lung. The SARS-CoV-2 infection triggered a dual mode of cell death pathways and caspase-8-dependent inflammatory responses may lead to the lung damage in the COVID-19 patients. These discoveries might assist the development of therapeutic strategies to treat COVID-19.


Subject(s)
Apoptosis/immunology , Betacoronavirus/pathogenicity , Caspase 8/immunology , Coronavirus Infections/immunology , Cytokine Release Syndrome/immunology , Necroptosis/immunology , Pneumonia, Viral/immunology , Pulmonary Fibrosis/immunology , Animals , COVID-19 , Caspase 8/genetics , Cell Line, Tumor , Chemokine CCL5/genetics , Chemokine CCL5/immunology , Chemokine CXCL10/genetics , Chemokine CXCL10/immunology , Coronavirus Infections/genetics , Coronavirus Infections/pathology , Coronavirus Infections/virology , Cytokine Release Syndrome/genetics , Cytokine Release Syndrome/pathology , Cytokine Release Syndrome/virology , Disease Models, Animal , Epithelial Cells/immunology , Epithelial Cells/pathology , Epithelial Cells/virology , Gene Expression Regulation , Humans , Interleukin-1beta/genetics , Interleukin-1beta/immunology , Interleukin-7/genetics , Interleukin-7/immunology , Interleukin-8/genetics , Interleukin-8/immunology , Lung/immunology , Lung/pathology , Lung/virology , Mice , Mice, Transgenic , Pandemics , Pneumonia, Viral/genetics , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Pulmonary Fibrosis/genetics , Pulmonary Fibrosis/pathology , Pulmonary Fibrosis/virology , SARS-CoV-2 , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/immunology
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