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1.
Mol Ther Methods Clin Dev ; 23: 108-118, 2021 Dec 10.
Article in English | MEDLINE | ID: covidwho-1379195

ABSTRACT

Because of the relatively limited understanding of coronavirus disease 2019 (COVID-19) pathogenesis, immunological analysis for vaccine development is needed. Mice and macaques were immunized with an inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine prepared by two inactivators. Various immunological indexes were tested, and viral challenges were performed on day 7 or 150 after booster immunization in monkeys. This inactivated SARS-CoV-2 vaccine was produced by sequential inactivation with formaldehyde followed by propiolactone. The various antibody responses and specific T cell responses to different viral antigens elicited in immunized animals were maintained for longer than 150 days. This comprehensive immune response could effectively protect vaccinated macaques by inhibiting viral replication in macaques and substantially alleviating immunopathological damage, and no clinical manifestation of immunopathogenicity was observed in immunized individuals during viral challenge. This candidate inactivated vaccine was identified as being effective against SARS-CoV-2 challenge in rhesus macaques.

2.
Zool Res ; 42(2): 161-169, 2021 Mar 18.
Article in English | MEDLINE | ID: covidwho-1070034

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus disease 2019 (COVID-19) continue to impact countries worldwide. At present, inadequate diagnosis and unreliable evaluation systems hinder the implementation and development of effective prevention and treatment strategies. Here, we conducted a horizontal and longitudinal study comparing the detection rates of SARS-CoV-2 nucleic acid in different types of samples collected from COVID-19 patients and SARS-CoV-2-infected monkeys. We also detected anti-SARS-CoV-2 antibodies in the above clinical and animal model samples to identify a reliable approach for the accurate diagnosis of SARS-CoV-2 infection. Results showed that, regardless of clinical symptoms, the highest detection levels of viral nucleic acid were found in sputum and tracheal brush samples, resulting in a high and stable diagnosis rate. Anti-SARS-CoV-2 immunoglobulin M (IgM) and G (IgG) antibodies were not detected in 6.90% of COVID-19 patients. Furthermore, integration of nucleic acid detection results from the various sample types did not improve the diagnosis rate. Moreover, dynamic changes in SARS-CoV-2 viral load were more obvious in sputum and tracheal brushes than in nasal and throat swabs. Thus, SARS-CoV-2 nucleic acid detection in sputum and tracheal brushes was the least affected by infection route, disease progression, and individual differences. Therefore, SARS-CoV-2 nucleic acid detection using lower respiratory tract samples alone is reliable for COVID-19 diagnosis and study.


Subject(s)
COVID-19 Testing/veterinary , COVID-19/diagnosis , SARS-CoV-2/genetics , Animals , Antibodies, Viral , Disease Models, Animal , Haplorhini , Humans , Longitudinal Studies , Pharynx/virology , Predictive Value of Tests , SARS-CoV-2/immunology , Specimen Handling , Sputum/virology
3.
Signal Transduct Target Ther ; 5(1): 294, 2020 12 24.
Article in English | MEDLINE | ID: covidwho-997816

ABSTRACT

Understanding the processes of immune regulation in patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is crucial for improving treatment. Here, we performed longitudinal whole-transcriptome RNA sequencing on peripheral blood mononuclear cell (PBMC) samples from 18 patients with coronavirus disease 2019 (COVID-19) during their treatment, convalescence, and rehabilitation. After analyzing the regulatory networks of differentially expressed messenger RNAs (mRNAs), microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) between the different clinical stages, we found that humoral immunity and type I interferon response were significantly downregulated, while robust T-cell activation and differentiation at the whole transcriptome level constituted the main events that occurred during recovery from COVID-19. The formation of this T cell immune response might be driven by the activation of activating protein-1 (AP-1) related signaling pathway and was weakly affected by other clinical features. These findings uncovered the dynamic pattern of immune responses and indicated the key role of T cell immunity in the creation of immune protection against this disease.


Subject(s)
COVID-19/genetics , Immunity, Humoral/genetics , T-Lymphocytes/metabolism , Transcriptome/genetics , COVID-19/epidemiology , COVID-19/pathology , Female , Humans , Immunity, Humoral/immunology , Leukocytes, Mononuclear/metabolism , Male , MicroRNAs , RNA, Long Noncoding/genetics , RNA-Seq , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , T-Lymphocytes/immunology , T-Lymphocytes/pathology , Transcription Factor AP-1/genetics
4.
PLoS Pathog ; 16(11): e1008949, 2020 11.
Article in English | MEDLINE | ID: covidwho-922716

ABSTRACT

The COVID-19 has emerged as an epidemic, causing severe pneumonia with a high infection rate globally. To better understand the pathogenesis caused by SARS-CoV-2, we developed a rhesus macaque model to mimic natural infection via the nasal route, resulting in the SARS-CoV-2 virus shedding in the nose and stool up to 27 days. Importantly, we observed the pathological progression of marked interstitial pneumonia in the infected animals on 5-7 dpi, with virus dissemination widely occurring in the lower respiratory tract and lymph nodes, and viral RNA was consistently detected from 5 to 21 dpi. During the infection period, the kinetics response of T cells was revealed to contribute to COVID-19 progression. Our findings implied that the antiviral response of T cells was suppressed after 3 days post infection, which might be related to increases in the Treg cell population in PBMCs. Moreover, two waves of the enhanced production of cytokines (TGF-α, IL-4, IL-6, GM-CSF, IL-10, IL-15, IL-1ß), chemokines (MCP-1/CCL2, IL-8/CXCL8, and MIP-1ß/CCL4) were detected in lung tissue. Our data collected from this model suggested that T cell response and cytokine/chemokine changes in lung should be considered as evaluation parameters for COVID-19 treatment and vaccine development, besides of observation of virus shedding and pathological analysis.


Subject(s)
Betacoronavirus/pathogenicity , Coronavirus Infections/pathology , Pneumonia, Viral/pathology , Animals , COVID-19 , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Cytokines/immunology , Disease Models, Animal , Lung/immunology , Lung/pathology , Macaca mulatta , Pandemics , Pneumonia, Viral/virology , SARS-CoV-2 , Viral Load/methods , Virulence , Virus Shedding
5.
J Med Virol ; 92(11): 2830-2838, 2020 11.
Article in English | MEDLINE | ID: covidwho-848038

ABSTRACT

Coronavirus disease 2019, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), leads to a series of clinical symptoms of respiratory and pulmonary inflammatory reactions via unknown pathologic mechanisms related to the viral infection process in tracheal or bronchial epithelial cells. Investigation of this viral infection in the human bronchial epithelial cell line (16HBE) suggests that SARS-CoV-2 can enter these cells through interaction between its membrane-localized S protein with the angiotensin-converting enzyme 2 molecule on the host cell membrane. Further observation indicates distinct viral replication with a dynamic and moderate increase, whereby viral replication does not lead to a specific cytopathic effect but maintains a continuous release of progeny virions from infected cells. Although messenger RNA expression of various innate immune signaling molecules is altered in the cells, transcription of interferons-α (IFN-α), IFN-ß, and IFN-γ is unchanged. Furthermore, expression of some interleukins (IL) related to inflammatory reactions, such as IL-6, IL-2, and IL-8, is maintained at low levels, whereas that of ILs involved in immune regulation is upregulated. Interestingly, IL-22, an IL that functions mainly in tissue repair, shows very high expression. Collectively, these data suggest a distinct infection process for this virus in respiratory epithelial cells, which may be linked to its clinicopathological mechanism.


Subject(s)
Bronchi/cytology , Epithelial Cells/virology , SARS-CoV-2/physiology , Virus Replication , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/virology , Cell Line , Cytopathogenic Effect, Viral/immunology , Epithelial Cells/immunology , Humans , Immunity, Innate , Interleukins/immunology , Spike Glycoprotein, Coronavirus/metabolism
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