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1.
Life ; 12(6):793, 2022.
Article in English | MDPI | ID: covidwho-1869690

ABSTRACT

The ACE2 receptor, as the potential entrance site of SARS-CoV-2-affected cells, plays a crucial role in spreading infection. The DX600 peptide is a competitive inhibitor of ACE2. We previously constructed the 68Ga-labeled DOTA-DX600 (also known as 68Ga-HZ20) peptide and confirmed its ACE2 binding ability both in vitro and in vivo. In this research, we aimed to investigate the noninvasive mapping of ACE2 expression in fowl using 68Ga-HZ20 micro-PET. We chose pigeons as an animal model and first studied the administration method of 68Ga-HZ20 by direct site injection or intravenous injection. Then, the dynamic micro-PET scan of 68Ga-HZ20 was conducted at 0–40 min. Additionally, 18F-FDG was used for comparison. Finally, the pigeons were sacrificed, and the main organs were collected for further immunoPET and IHC staining. Micro PET/CT imaging results showed that 68Ga-HZ20 uptake was distributed from the heart at the preliminary injection to the kidneys, liver, stomach, and lungs over time, where the highest uptake was observed in the kidneys (SUVmax = 6.95, 20 min) and lung (SUVmax = 1.11, 20 min). Immunohistochemical experiments were carried out on its main organs. Compared to the SUVmax data, the IHC results showed that ACE2 was highly expressed in both kidneys and intestines, and the optimal imaging time was determined to be 20 min after injection through correlation analysis. These results indicated that 68Ga-HZ20 is a potential target molecule for SARS-CoV-2 in fowl, which is worthy of promotion and further study.

2.
J Med Virol ; 94(7): 3203-3222, 2022 Jul.
Article in English | MEDLINE | ID: covidwho-1750409

ABSTRACT

Circular RNAs (circRNAs) are a newly recognized component of the transcriptome with critical roles in autoimmune diseases and viral pathogenesis. To address the importance of circRNA in RNA viral transcriptome, we systematically identified and characterized circRNAs encoded by the RNA genomes of betacoronaviruses using both bioinformatical and experimental approaches. We predicted 351, 224, and 2764 circRNAs derived from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), SARS-CoV, and Middle East respiratory syndrome coronavirus, respectively. We experimentally identified 75 potential SARS-CoV-2 circRNAs from RNA samples extracted from SARS-CoV-2-infected Vero E6 cells. A systematic comparison of viral and host circRNA features, including abundance, strand preference, length distribution, circular exon numbers, and breakpoint sequences, demonstrated that coronavirus-derived circRNAs had a spliceosome-independent origin. We further showed that back-splice junctions (BSJs) captured by inverse reverse-transcription polymerase chain reaction have different level of resistance to RNase R. Through northern blotting with a BSJ-spanning probe targeting N gene, we identified three RNase R-resistant bands that represent SARS-CoV-2 circRNAs that are detected cytoplasmic by single-molecule and amplified fluorescence in situ hybridization assays. Lastly, analyses of 169 sequenced BSJs showed that both back-splice and forward-splice junctions were flanked by homologous and reverse complementary sequences, including but not limited to the canonical transcriptional regulatory sequences. Our findings highlight circRNAs as an important component of the coronavirus transcriptome, offer important evaluation of bioinformatic tools in the analysis of circRNAs from an RNA genome, and shed light on the mechanism of discontinuous RNA synthesis.


Subject(s)
COVID-19 , Middle East Respiratory Syndrome Coronavirus , Humans , In Situ Hybridization, Fluorescence , Middle East Respiratory Syndrome Coronavirus/genetics , RNA, Circular/genetics , SARS-CoV-2/genetics , Spliceosomes/genetics
5.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-322503

ABSTRACT

Background: The Corona Virus Disease 2019 (COVID-19) is spreading globally now. However, the clinical presentation that predict prognosis of the patients are still largely unknow. Methods: We enrolled 393 patients infected with COVID-19 and 30 patients with common pulmonary bulla and reviewed their clinical features to evaluate the potential prognostic value of pulmonary vesicles, especially in the patients with severe symptoms. One COVID-19 patient with vesicles was treated by bullectomy for last resort, and its characteristics of the patient’s perioperative laboratory tests was analyzed. The pathological findings of bullectomy were described and compared with those of common bulla cases. Results: Patients infected with COVID-19 showed more dependence on ventilator, occurrence of super resistant bacteria, and prone to vesicle formation than common bulla (p<0.05). Disease severity is associated with age, sex, and usage of ventilator, ECMO and antibiotics, super resistance bacteria and vesicle formation (p<0.05). The average mortality rate of COVID-19 patients was 4.10% (25.4% in severe patients, 0.00% in mild patients). Interestingly, the mortality rate further increased in severe patients with pulmonary vesicles than those without pulmonary vesicles (35.7% vs 22.4%, p=0.0442). One COVID-19 patient with vesicles underwent bullectomy and had a poor prognosis, who showed diffuse alveolar damage and extensive necrosis in bullectomy specimen. Conclusions: Patients infected with COVID-19 are more prone to form pulmonary vesicles showed on chest CT scans, as an important poor prognosis factor, especially in the severe patients.

6.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-311706

ABSTRACT

The SARS-CoV-2 pandemic poses an unprecedented public health crisis. Accumulating evidences suggest that SARS-CoV-2 infection causes dysregulation of immune system. However, the unique signature of early immune responses remains elusive. We characterized the transcriptome of rhesus macaques and mice infected with SARS-CoV-2. Alarmin S100A8 was robustly induced by SARS-CoV-2 in animal models as well as in COVID-19 patients. Paquinimod, a specific inhibitor of S100A8/A9, could reduce inflammatory response and rescue the pneumonia with substantial reduction of viral titers in SASR-CoV-2 infected animals. Remarkably, Paquinimod treatment resulted in 100% survival of mice in a lethal model of mouse coronavirus (MHV) infection. A novel group of neutrophils that contributed to the uncontrolled inflammation and onset of COVID-19 were dramatically induced by coronavirus infections. Paquinimod treatment could reduce these neutrophils and regain antiviral responses, unveiling key roles of S100A8/A9 and noncanonical neutrophils in the pathogenesis of COVID-19, highlighting new opportunities for therapeutic intervention.Funding: This work was supported by the National Natural Science Foundation of China (31570891;31872736), the National Key Research and Development Program of China (2016YFA0500302;2020YFA0707800), the National Key Research and Development Program (2020YFA0707500) and the Strategic Priority Research Program (XDB29010000). Xiangxi Wang was supported by Ten Thousand Talent Program and the NSFS Innovative Research Group (81921005). We thank National Mega projects of China for Major Infectious Diseases (2017ZX10304402), CAMS initiative for Innovative Medicine of China (2016-12M-2-006) and The National Natural Science Foundation of China (82041008) for the support on the animal model study. Conflict of Interest: The authors have no conflicts of interest to declare.Ethical Approval: All experiments with live SARS-CoV-2 viruses were carried out in the enhanced biosafety level 3 (P3+) facilities in the Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences (CAMS) approved by the National Health Commission of the People’s Republic of China. All animals care and use were in accordance with the Guide for the Care and Use of Laboratory Animals of the Chinese Association for Laboratory Animal Science. All procedures of animal handling were approved by the Animal Care Committee of Peking University Health Science Center.

7.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-325409

ABSTRACT

Background: Evidence shows that inflammatory responses play multiphasic roles in stroke pathogenesis. Ruxolitinib (Rux), a selective oral JAK 1/2 inhibitor, is efficacious in COVID-19 by reducing inflammation via the JAK2/STAT3 pathway. MethodsHere, we investigated whether JAK2 inhibition has neuroprotective effects against ischemic stroke (IS) in MCAO mice in vivo and in vitro oxygen-glucose deprivation/reoxygenation (OGD/R) model, and explored the potential molecular mechanisms. Rux was applied to MCAO mice. Immunofluorescence staining, RT-qPCR, and western blots were used to measure the expression of NLRP3 inflammation components and proinflammatory cytokines as well as JAK2/STAT3 pathway. Local STAT3 deficiency in brain tissue was established to investigate the interplay between NLRP3 and STAT3 signaling.ResultsRux treatment obviously improved neurological scores, decreased the infarct size and ameliorated cerebral edema 3 days after stroke. In addition, immunofluorescence staining and western blots showed that Rux application inhibited the expression of NLRP3 inflammasome components, proteins related to the NLRP3 inflammasome and phosphorylated STAT3 (p-STAT3) in neurons. Furthermore, Rux administration inhibited the expression of proinflammatory cytokines, including TNF-α, IFN-γ, HMBG1, IL-1β, IL-2, and IL-6 in middle cerebral artery occlusion (MCAO) model mice, suggesting that Rux may alleviate IS injury by inhibiting proinflammatory reactions via JAK2/STAT3 signaling pathway regulation. Local STAT3 deficiency decreased histone H3 and H4 acetylation on the NLRP3 promoter and the NLRP3 inflammasome component expression, indicating that the NLRP3 inflammasome may be directly regulated by STAT3 signaling. Finally, the effect of Rux on the NLRP3 inflammasome was further assessed in a HT22 cell OGD/R model in vitro. Rux application markedly suppressed lipopolysaccharide (LPS)-induced NLRP3 inflammasome secretion and JAK2/STAT3 pathway activation in vitro the in OGD/R HT22 cell model.ConclusionJAK2 inhibition by Rux in MCAO mice decreased STAT3 phosphorylation, thus inhibiting downstream proinflammatory cytokines and H3 and H4 acetylation on the NLRP3 promoter, resulting in downregulation of NLRP3 inflammasome component expression.

8.
Acta Pharmacol Sin ; 2021 Nov 23.
Article in English | MEDLINE | ID: covidwho-1671539

ABSTRACT

The spike protein of SARS-CoV-2 interacts with angiotensin-converting enzyme 2 (ACE2) of human respiratory epithelial cells, which leads to infection. Furthermore, low-dose radiation has been found to reduce inflammation and aid the curing of COVID-19. The receptor binding domain (RBD), a recombinant spike protein with a His tag at the C-terminus, binds to ACE2 in human body. We thus constructed a radioiodinated RBD as a molecule-targeted probe to non-invasively explore ACE2 expression in vivo, and to investigate radiotherapy pathway for inhibiting ACE2. RBD was labeled with [124I]NaI using an N-bromosuccinimide (NBS)-mediated method, and 124I-RBD was obtained after purification with a specific activity of 28.9 GBq/nmol. Its radiochemical purity was (RCP) over 90% in saline for 5 days. The dissociation constant of 124I-RBD binding to hACE2 was 75.7 nM. The uptake of 124I-RBD by HeLaACE+ cells at 2 h was 2.96% ± 0.35%, which could be substantially blocked by an excessive amount of RBD, and drop to 1.71% ± 0.23%. In BALB/c mice, the biodistribution of 124I-RBD after intravenous injection showed a moderate metabolism rate, and its 24 h-post injection (p.i.) organ distribution was similar to the expression profile in body. Micro-PET imaging of mice after intrapulmonary injection showed high uptake of lung at 1, 4, 24 h p.i.. In conclusion, the experimental results demonstrate the potential of 124I-RBD as a novel targeted molecular probe for COVID-19. This probe may be used for non-invasive ACE2 mapping in mammals.

9.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-294592

ABSTRACT

Angiotensin-converting enzyme 2 (ACE2), a transmembrane protein, is the main entry point for certain coronaviruses including the new coronavirus SARS-CoV-2 to enter cells. Synthesizing the PET imaging probe Al 18 F-DX600-BCH which is high-affinity ACE2 is aim to detect the expression of ACE2 in body and monitor the therapeutic effect. The Al 18 F-DX600-BCH was obtained manually with a 20.4% ± 5.2% radiochemical yield without attenuation correction and an over 99% purified radiochemical purity, being stable in vitro within 4 hours and cleared rapidly in blood (the half-lives of the distribution phase and clearance phase were 2.12 min and 25.31 min, respectively). Results of both biodistribution and PET imaging showed that Al 18 F-DX600-BCH was highly accumulated in the kidney (SUV kidney/normal > 50), and specific uptake in testis (SUV testis/normal > 10) was observed in rat images. The kidney (++), gastrointestinal (++) and bronchial (+++) cells were evidenced of ACE2 positive by IHC staining of rats. A total of 10 volunteers were enrolled and received PET/CT 1 hour and 2 hours after injection or dynamic PET/CT during 0-330 seconds (NCT04542863), from which strong radioactivity accumulation was mostly observed in the genitourinary system (SUV renal cortex = 32.00, SUV testis = 4.56), and moderate accumulation in conjunctiva and nasal mucosa for several cases. This work firstly reported the probe Al 18 F-DX600-BCH targeting ACE2, conducting preliminary preclinical experiments and a total of 10 clinical transformations, which demonstrated the potential and possibility of non-invasive mapping of ACE2. Trial registration: ClinicalTrials.gov NCT04542863. Registered 9 September 2020.

10.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-293272

ABSTRACT

Angiotensin-converting enzyme 2 (ACE2), a transmembrane protein, is the main entry point for certain coronaviruses including the new coronavirus SARS-CoV-2 to enter cells. Synthesizing the PET imaging probe Al 18 F-DX600-BCH which is high-affinity ACE2 is aim to detect the expression of ACE2 in body and monitor the therapeutic effect. The Al 18 F-DX600-BCH was obtained manually with a 20.4% ± 5.2% radiochemical yield without attenuation correction and an over 99% purified radiochemical purity, being stable in vitro within 4 hours and cleared rapidly in blood (the half-lives of the distribution phase and clearance phase were 2.12 min and 25.31 min, respectively). Results of both biodistribution and PET imaging showed that Al 18 F-DX600-BCH was highly accumulated in the kidney (SUV kidney/normal > 50), and specific uptake in testis (SUV testis/normal > 10) was observed in rat images. The kidney (++), gastrointestinal (++) and bronchial (+++) cells were evidenced of ACE2 positive by IHC staining of rats. A total of 10 volunteers were enrolled and received PET/CT 1 hour and 2 hours after injection or dynamic PET/CT during 0-330 seconds (NCT04542863), from which strong radioactivity accumulation was mostly observed in the genitourinary system (SUV renal cortex = 32.00, SUV testis = 4.56), and moderate accumulation in conjunctiva and nasal mucosa for several cases. This work firstly reported the probe Al 18 F-DX600-BCH targeting ACE2, conducting preliminary preclinical experiments and a total of 10 clinical transformations, which demonstrated the potential and possibility of non-invasive mapping of ACE2. Trial registration: ClinicalTrials.gov NCT04542863. Registered 9 September 2020.

11.
Mol Biomed ; 2(1): 29, 2021.
Article in English | MEDLINE | ID: covidwho-1515465

ABSTRACT

In the face of the emerging variants of SARS-CoV-2, there is an urgent need to develop a vaccine that can induce fast, effective, long-lasting and broad protective immunity against SARS-CoV-2. Here, we developed a trimeric SARS-CoV-2 S protein vaccine candidate adjuvanted by PIKA, which can induce robust cellular and humoral immune responses. The results showed a high level of neutralizing antibodies induced by the vaccine was maintained for at least 400 days. In the study of non-human primates, PIKA adjuvanted S-trimer induced high SARS-CoV-2 neutralization titers and protected from virus replication in the lung following SARS-CoV-2 challenge. In addition, the long-term neutralizing antibody response induced by S-trimer vaccine adjuvanted by PIKA could neutralize multiple SARS-CoV-2 variants and there is no obvious different among the SARS- CoV-2 variants of interest or concern, including B.1.351, B.1.1.7, P.1, B.1.617.1 and B.1.617.2 variants. These data support the utility of S-trimer protein adjuvanted by PIKA as a potential vaccine candidate against SARS-CoV-2 infection. Supplementary Information: The online version contains supplementary material available at 10.1186/s43556-021-00054-z.

12.
Vaccine ; 39(48): 7001-7011, 2021 11 26.
Article in English | MEDLINE | ID: covidwho-1488001

ABSTRACT

COVID-19 pandemic has severely impacted the public health and social economy worldwide. A safe, effective, and affordable vaccine against SARS-CoV-2 infections/diseases is urgently needed. We have been developing a recombinant vaccine based on a prefusion-stabilized spike trimer of SARS-CoV-2 and formulated with aluminium hydroxide and CpG 7909. The spike protein was expressed in Chinese hamster ovary (CHO) cells, purified, and prepared as a stable formulation with the dual adjuvant. Immunogenicity studies showed that candidate vaccines elicited robust neutralizing antibody responses and substantial CD4+ T cell responses in both mice and non-human primates. And vaccine-induced neutralizing antibodies persisted at high level for at least 6 months. Challenge studies demonstrated that candidate vaccine reduced the viral loads and inflammation in the lungs of SARS-CoV-2 infected golden Syrian hamsters significantly. In addition, the vaccine-induced antibodies showed cross-neutralization activity against B.1.1.7 and B.1.351 variants. These data suggest candidate vaccine is efficacious in preventing SARS-CoV-2 infections and associated pneumonia, thereby justifying ongoing phase I/II clinical studies in China (NCT04982068 and NCT04990544).


Subject(s)
COVID-19 Vaccines , COVID-19 , Alum Compounds , Aluminum Hydroxide , Animals , Antibodies, Neutralizing , Antibodies, Viral , CHO Cells , Cricetinae , Cricetulus , Humans , Mice , Pandemics , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/genetics
13.
Signal Transduct Target Ther ; 6(1): 347, 2021 09 25.
Article in English | MEDLINE | ID: covidwho-1437669

ABSTRACT

SARS-CoV-2 mutations contribute to increased viral transmissibility and immune escape, compromising the effectiveness of existing vaccines and neutralizing antibodies. An in-depth investigation on COVID-19 pathogenesis is urgently needed to develop a strategy against SARS-CoV-2 variants. Here, we identified CD147 as a universal receptor for SARS-CoV-2 and its variants. Meanwhile, Meplazeumab, a humanized anti-CD147 antibody, could block cellular entry of SARS-CoV-2 and its variants-alpha, beta, gamma, and delta, with inhibition rates of 68.7, 75.7, 52.1, 52.1, and 62.3% at 60 µg/ml, respectively. Furthermore, humanized CD147 transgenic mice were susceptible to SARS-CoV-2 and its two variants, alpha and beta. When infected, these mice developed exudative alveolar pneumonia, featured by immune responses involving alveoli-infiltrated macrophages, neutrophils, and lymphocytes and activation of IL-17 signaling pathway. Mechanistically, we proposed that severe COVID-19-related cytokine storm is induced by a "spike protein-CD147-CyPA signaling axis": Infection of SARS-CoV-2 through CD147 initiated the JAK-STAT pathway, which further induced expression of cyclophilin A (CyPA); CyPA reciprocally bound to CD147 and triggered MAPK pathway. Consequently, the MAPK pathway regulated the expression of cytokines and chemokines, which promoted the development of cytokine storm. Importantly, Meplazumab could effectively inhibit viral entry and inflammation caused by SARS-CoV-2 and its variants. Therefore, our findings provided a new perspective for severe COVID-19-related pathogenesis. Furthermore, the validated universal receptor for SARS-CoV-2 and its variants can be targeted for COVID-19 treatment.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Antibodies, Monoclonal, Humanized/pharmacology , Basigin/antagonists & inhibitors , Basigin/metabolism , COVID-19/drug therapy , COVID-19/metabolism , Cytokine Release Syndrome/drug therapy , SARS-CoV-2/metabolism , Angiotensin-Converting Enzyme 2/genetics , Animals , Basigin/genetics , COVID-19/genetics , Chlorocebus aethiops , Cytokine Release Syndrome/genetics , Cytokine Release Syndrome/metabolism , Humans , MAP Kinase Signaling System/drug effects , MAP Kinase Signaling System/genetics , Mice , Mice, Transgenic , SARS-CoV-2/genetics , Vero Cells
14.
Signal Transduct Target Ther ; 6(1): 337, 2021 09 06.
Article in English | MEDLINE | ID: covidwho-1402050

ABSTRACT

SARS-CoV-2 has been reported to show a capacity for invading the brains of humans and model animals. However, it remains unclear whether and how SARS-CoV-2 crosses the blood-brain barrier (BBB). Herein, SARS-CoV-2 RNA was occasionally detected in the vascular wall and perivascular space, as well as in brain microvascular endothelial cells (BMECs) in the infected K18-hACE2 transgenic mice. Moreover, the permeability of the infected vessel was increased. Furthermore, disintegrity of BBB was discovered in the infected hamsters by administration of Evans blue. Interestingly, the expression of claudin5, ZO-1, occludin and the ultrastructure of tight junctions (TJs) showed unchanged, whereas, the basement membrane was disrupted in the infected animals. Using an in vitro BBB model that comprises primary BMECs with astrocytes, SARS-CoV-2 was found to infect and cross through the BMECs. Consistent with in vivo experiments, the expression of MMP9 was increased and collagen IV was decreased while the markers for TJs were not altered in the SARS-CoV-2-infected BMECs. Besides, inflammatory responses including vasculitis, glial activation, and upregulated inflammatory factors occurred after SARS-CoV-2 infection. Overall, our results provide evidence supporting that SARS-CoV-2 can cross the BBB in a transcellular pathway accompanied with basement membrane disrupted without obvious alteration of TJs.


Subject(s)
Basement Membrane/metabolism , Blood-Brain Barrier/metabolism , COVID-19/metabolism , SARS-CoV-2/metabolism , Tight Junctions/metabolism , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , Basement Membrane/pathology , Basement Membrane/virology , Blood-Brain Barrier/pathology , Blood-Brain Barrier/virology , COVID-19/genetics , COVID-19/pathology , Chlorocebus aethiops , Disease Models, Animal , Humans , Matrix Metalloproteinase 9/genetics , Matrix Metalloproteinase 9/metabolism , Mice , Mice, Transgenic , SARS-CoV-2/genetics , Tight Junctions/genetics , Tight Junctions/pathology , Tight Junctions/virology , Vero Cells
15.
Adv Sci (Weinh) ; 8(16): e2100965, 2021 08.
Article in English | MEDLINE | ID: covidwho-1281195

ABSTRACT

Rapid progress has been made to identify and study the causative agent leading to coronavirus disease 2019 (COVID-19) but many questions including who is most susceptible and what determines severity remain unanswered. Angiotensin-converting enzyme 2 (ACE2) is a key factor in the infection process of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). In this study, molecularly specific positron emission tomography imaging agents for targeting ACE2 are first developed, and these novel agents are evaluated in vitro, in preclinical model systems, and in a first-in-human translational ACE2 imaging of healthy volunteers and a SARS-CoV-2 recovered patient (NCT04422457). ACE2 expression levels in different organs in live subjects are quantitatively delineated and observable differences are measured in the patient recovered from COVID-19. Surprising sites of uptake in the breast, reproductive system and very low uptake in pulmonary tissues are reported. This novel method can add a unique tool to facilitate SARS-CoV-2 related research and improve understanding of this enigmatic disease. Molecular imaging provides quantitative annotation of ACE2, the SARS-CoV-2 entry receptor, to noninvasively monitor organs impacted by the COVID-19.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/metabolism , COVID-19/virology , Peptides/pharmacokinetics , SARS-CoV-2/metabolism , Animals , COVID-19/pathology , Cells, Cultured , Female , Gallium Radioisotopes/pharmacokinetics , Humans , Male , Mice , Positron Emission Tomography Computed Tomography , Protein Binding , SARS-CoV-2/isolation & purification , SARS-CoV-2/pathogenicity , Tissue Distribution , Xenograft Model Antitumor Assays
16.
Clin Infect Dis ; 71(15): 778-785, 2020 07 28.
Article in English | MEDLINE | ID: covidwho-1217823

ABSTRACT

BACKGROUND: The emergence of coronavirus disease 2019 (COVID-19) is a major healthcare threat. The current method of detection involves a quantitative polymerase chain reaction (qPCR)-based technique, which identifies the viral nucleic acids when present in sufficient quantity. False-negative results can be achieved and failure to quarantine the infected patient would be a major setback in containing the viral transmission. We aim to describe the time kinetics of various antibodies produced against the 2019 novel coronavirus (SARS-CoV-2) and evaluate the potential of antibody testing to diagnose COVID-19. METHODS: The host humoral response against SARS-CoV-2, including IgA, IgM, and IgG response, was examined by using an ELISA-based assay on the recombinant viral nucleocapsid protein. 208 plasma samples were collected from 82 confirmed and 58 probable cases (qPCR negative but with typical manifestation). The diagnostic value of IgM was evaluated in this cohort. RESULTS: The median duration of IgM and IgA antibody detection was 5 (IQR, 3-6) days, while IgG was detected 14 (IQR, 10-18) days after symptom onset, with a positive rate of 85.4%, 92.7%, and 77.9%, respectively. In confirmed and probable cases, the positive rates of IgM antibodies were 75.6% and 93.1%, respectively. The detection efficiency by IgM ELISA is higher than that of qPCR after 5.5 days of symptom onset. The positive detection rate is significantly increased (98.6%) when combining IgM ELISA assay with PCR for each patient compared with a single qPCR test (51.9%). CONCLUSIONS: The humoral response to SARS-CoV-2 can aid in the diagnosis of COVID-19, including subclinical cases.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/diagnosis , Coronavirus Infections/immunology , Immunity, Humoral/immunology , Pneumonia, Viral/diagnosis , Pneumonia, Viral/immunology , Adult , Amino Acid Sequence , Antibodies, Viral/immunology , COVID-19 , Child , Child, Preschool , Coronavirus Infections/virology , Enzyme-Linked Immunosorbent Assay/methods , Female , Humans , Male , Middle Aged , Pandemics , Pneumonia, Viral/virology , Polymerase Chain Reaction/methods , SARS-CoV-2
17.
Cell Discov ; 7(1): 24, 2021 Apr 13.
Article in English | MEDLINE | ID: covidwho-1182824

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) invades the alveoli, where abundant alveolar macrophages (AMs) reside. How AMs respond to SARS-CoV-2 invasion remains elusive. Here, we show that classically activated M1 AMs facilitate viral spread; however, alternatively activated M2 AMs limit the spread. M1 AMs utilize cellular softness to efficiently take up SARS-CoV-2. Subsequently, the invaded viruses take over the endo-lysosomal system to escape. M1 AMs have a lower endosomal pH, favoring membrane fusion and allowing the entry of viral RNA from the endosomes into the cytoplasm, where the virus achieves replication and is packaged to be released. In contrast, M2 AMs have a higher endosomal pH but a lower lysosomal pH, thus delivering the virus to lysosomes for degradation. In hACE2 transgenic mouse model, M1 AMs are found to facilitate SARS-CoV-2 infection of the lungs. These findings provide insights into the complex roles of AMs during SARS-CoV-2 infection, along with potential therapeutic targets.

18.
World J Pediatr ; 17(3): 253-262, 2021 06.
Article in English | MEDLINE | ID: covidwho-1176425

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging disease. The consequences of SARS-CoV-2 exposure in infants remain unknown. Therefore, this study aims to investigate whether neonates born to mothers with COVID-19 have adverse brain development. METHODS: This multicenter observational study was conducted at two designated maternal and children's hospitals in Hubei Province, mainland China from February 1, 2020 to May 15, 2020. Neonates born to mothers with COVID-19 were enrolled. Brain magnetic resonance imaging (MRI) findings, and volumes of grey and white matters, and physical growth parameters were observed at 44 weeks corrected gestational age. RESULTS: Of 72 neonates born to mothers with COVID-19, 8 (11%) were diagnosed with COVID-19, 8 (11%) were critically ill, and no deaths were reported. Among the eight neonates that underwent brain MRI at corrected gestational age of 44 weeks, five neonates were diagnosed with COVID-19. Among these five neonates, three presented abnormal MRI findings including abnormal signal in white matter and delayed myelination in newborn 2, delayed myelination and brain dysplasia in newborn 3, and abnormal signal in the bilateral periventricular in newborn 5. The other three neonates without COVID-19 presented no significantly changes of brain MRI findings and the volumes of grey matter and white matter compared to those of healthy newborns at the equivalent age (P > 0.05). Physical growth parameters for weight, length, and head circumference at gestational age of 44 weeks were all above the 3rd percentile for all neonates. CONCLUSIONS: Some of the neonates born to mothers with COVID-19 had abnormal brain MRI findings but these neonates did not appear to have poor physical growth. These findings may provide the information on the follow-up schedule on the neonates exposed to SARS-CoV-2, but further study is required to evaluate the association between the abnormal MRI findings and the exposure to SARS-CoV-2.


Subject(s)
Brain/abnormalities , Brain/diagnostic imaging , COVID-19/transmission , Infectious Disease Transmission, Vertical , Magnetic Resonance Imaging , COVID-19/epidemiology , China/epidemiology , Female , Humans , Infant, Newborn , Male , Pandemics , Pregnancy , SARS-CoV-2
19.
Vaccines (Basel) ; 9(4)2021 Apr 01.
Article in English | MEDLINE | ID: covidwho-1167776

ABSTRACT

BNT162b2 is a highly efficacious mRNA vaccine approved to prevent COVID-19. This brief report describes the immunogenicity and anti-viral protective effect of BNT162b2 in hACE2 transgenic mice. Prime-boost immunization with BNT162b2 elicited high titers in neutralizing antibodies against SARS-CoV-2, which correlated with viral clearance and alleviated lung lesions in these mice after viral challenge.

20.
Cell Host Microbe ; 29(2): 222-235.e4, 2021 02 10.
Article in English | MEDLINE | ID: covidwho-987276

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic poses an unprecedented public health crisis. Evidence suggests that SARS-CoV-2 infection causes dysregulation of the immune system. However, the unique signature of early immune responses remains elusive. We characterized the transcriptome of rhesus macaques and mice infected with SARS-CoV-2. Alarmin S100A8 was robustly induced in SARS-CoV-2-infected animal models as well as in COVID-19 patients. Paquinimod, a specific inhibitor of S100A8/A9, could rescue the pneumonia with substantial reduction of viral loads in SARS-CoV-2-infected mice. Remarkably, Paquinimod treatment resulted in almost 100% survival in a lethal model of mouse coronavirus infection using the mouse hepatitis virus (MHV). A group of neutrophils that contributes to the uncontrolled pathological damage and onset of COVID-19 was dramatically induced by coronavirus infection. Paquinimod treatment could reduce these neutrophils and regain anti-viral responses, unveiling key roles of S100A8/A9 and aberrant neutrophils in the pathogenesis of COVID-19, highlighting new opportunities for therapeutic intervention.


Subject(s)
Alarmins/pharmacology , Antiviral Agents/pharmacology , COVID-19/drug therapy , Neutrophils/drug effects , SARS-CoV-2/drug effects , Animals , COVID-19/metabolism , COVID-19/virology , Disease Models, Animal , Female , Humans , Macaca mulatta , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Neutrophils/metabolism , Transcriptome , Viral Load
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