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1.
China Biotechnology ; 42(5):117-123, 2022.
Article in Chinese | Scopus | ID: covidwho-2090951

ABSTRACT

Objective: Hepatitis B virus core protein HBc was used as vector to construct virus-like particles expressing novel coronavirus spike protein receptor binding domain RBD, and their immunogenicity was identified, which provides a new idea for the development of COVID-19 vaccines. Methods: The amino acid coding sequence 78 and 81 of hepatitis B virus core protein HBc (1-183 aa) were inserted into novel coronavirus spike protein receptor binding domain RBD and ligated by flexible linker (G4S) 3. After sequence optimization, the fusion gene was cloned into prokaryotic expression vector pET-28a (+) and transformed into expression strain Rosetta. After induced expression in self-inducing medium, the virus-like particles (VLPs) were purified by sucrose density gradient centrifugation. VLPs were detected and identified by SDS-PAGE, Western blot and transmission electron microscope. BALB/c mice were immunized subcutaneously with the prepared VLPs in equal proportion with adjuvant. The specific antibodies in the serum of the mice were analyzed by ELISA to verify the immune effect of HBc-RBD VLPs. Results: Escherichia coli can express partially soluble VLPs in self-inducing medium. VLPs could be observed by transmission electron microscope after purification by sucrose density gradient centrifugation. Mice immunized with HBc-RBD VLPs produced specific antibodies against RBD antigen. Conclusion: VLPs displaying RBD antigen were successfully expressed in prokaryotic expression systems, and their immunogenicity was preliminarily verified by mouse experiment, which provides a new direction for the research and development of novel coronavirus vaccines. © 2022, China Biotechnology Press. All rights reserved.

2.
British Journal of Social Work ; : 19, 2021.
Article in English | Web of Science | ID: covidwho-1852945

ABSTRACT

The prevalence of child maltreatment is quite high during the coronavirus disease 2019 pandemic in rural Hubei province, and children from vulnerable families are at greater risk of self-harm behaviours. The impact of lockdown measures in Wuhan, China during the coronavirus disease 2019 pandemic on child maltreatment remains unknown. The present study attempted to estimate the prevalence of child maltreatment during this period, to identify risk factors, and the influence of child maltreatment. A representative sample of 1,062 school-aged children in rural Hubei province was surveyed. Results indicated that the prevalence of family violence, physical violence, emotional abuse and neglect during the lockdown period were 13.9, 13.7, 20.2 and 7.3 percent, respectively, and that of lifetime prevalence were 17.0, 13.9, 14.6 and 6.9 percent, respectively. And most victims did not seek official help. Boys were more likely to experience physical violence. Children from separated/divorced families tended to report more emotional abuse. Those having family members with a history of drug abuse and mental illness were more likely to experience neglect during the lockdown period. All types of child maltreatment were positively associated with self-harm behaviours. These findings highlight the importance of identifying at-risk children immediately and implementing timely intervention programmes to prevent self-harm behaviours for social workers and health professionals.

3.
MEDLINE;
Preprint in English | MEDLINE | ID: ppcovidwho-328526

ABSTRACT

The SARS-CoV-2 protein Nsp2 has been implicated in a wide range of viral processes, but its exact functions, and the structural basis of those functions, remain unknown. Here, we report an atomic model for full-length Nsp2 obtained by combining cryo-electron microscopy with deep learning-based structure prediction from AlphaFold2. The resulting structure reveals a highly-conserved zinc ion-binding site, suggesting a role for Nsp2 in RNA binding. Mapping emerging mutations from variants of SARS-CoV-2 on the resulting structure shows potential host-Nsp2 interaction regions. Using structural analysis together with affinity tagged purification mass spectrometry experiments, we identify Nsp2 mutants that are unable to interact with the actin-nucleation-promoting WASH protein complex or with GIGYF2, an inhibitor of translation initiation and modulator of ribosome-associated quality control. Our work suggests a potential role of Nsp2 in linking viral transcription within the viral replication-transcription complexes (RTC) to the translation initiation of the viral message. Collectively, the structure reported here, combined with mutant interaction mapping, provides a foundation for functional studies of this evolutionary conserved coronavirus protein and may assist future drug design.

4.
PubMed; 2021.
Preprint in English | PubMed | ID: ppcovidwho-8952

ABSTRACT

The SARS-CoV-2 protein Nsp2 has been implicated in a wide range of viral processes, but its exact functions, and the structural basis of those functions, remain unknown. Here, we report an atomic model for full-length Nsp2 obtained by combining cryo-electron microscopy with deep learning-based structure prediction from AlphaFold2. The resulting structure reveals a highly-conserved zinc ion-binding site, suggesting a role for Nsp2 in RNA binding. Mapping emerging mutations from variants of SARS-CoV-2 on the resulting structure shows potential host-Nsp2 interaction regions. Using structural analysis together with affinity tagged purification mass spectrometry experiments, we identify Nsp2 mutants that are unable to interact with the actin-nucleation-promoting WASH protein complex or with GIGYF2, an inhibitor of translation initiation and modulator of ribosome-associated quality control. Our work suggests a potential role of Nsp2 in linking viral transcription within the viral replication-transcription complexes (RTC) to the translation initiation of the viral message. Collectively, the structure reported here, combined with mutant interaction mapping, provides a foundation for functional studies of this evolutionary conserved coronavirus protein and may assist future drug design.

5.
Zhonghua Liu Xing Bing Xue Za Zhi ; 41(11): 1786-1790, 2020 Nov 10.
Article in Chinese | MEDLINE | ID: covidwho-970252

ABSTRACT

Objective: To understand the epidemiological characteristics of imported COVID-19 cases in Guangzhou and provide scientific basis for the prevention and control of the disease. Methods: The data of imported COVID-19 in Guangzhou reported as of April 1, 2020 were collected from National Notifiable Disease Report System of China. The software Excel 2010 and SPSS 19.0 were applied for data cleaning and statistical analysis. Results: As of April 1, 2020, a total of 103 imported COVID-19 cases had been reported in Guangzhou, in which 92 were confirmed cases and 11 were asymptomatic infection cases. The number of the confirmed imported cases accounted for 11.4% (92/806) in of the total in China at the same time. The male to female ratio of the cases was 1.58∶1 (63∶40). The median age of the cases was 31 years (P(25)-P(75):22-40 years), range of age was 11-63 years. The main occupational distributions of the cases were business services (41/103, 39.8%) and students (36/103, 35.0%). The imported cases whose destinations were 19 provinces and municipalities rather than Guangdong after entering the country accounted for 43.7%. The main source countries of infections were the United Kingdom (27/103, 26.2%), the Philippines (13/103, 12.6%), the United States (13/103, 12.6%) and Nigeria (7/103, 6.8%). There were 34 inbound flights from which the imported COVID-19 cases were detected, in which 10 flights (10/34, 29.4%) were found to carry more than 3 cases, with an average voyage time of (11.14±0.53) hours. A total of 29 imported cases(28.2%) showed symptoms before entering the country, and 65 cases (63.1%) had been isolated before the onset of the disease. The mean free activity time of the isolated cases after the onset was (6.76±0.79) days. The average number of the imported cases' close contacts was 53. There were 13 clusters of COVID-19 caused by the imported cases, involving 36 cases (including 1 imported associated case). Conclusions: The sources of the imported COVID-19 cases in Guangzhou were widely distributed, and no cases had been found to be infected on the flights. In the early stage of the imported epidemic, there was high risk for the spread of the epidemic. Strengthened prevention and control of imported COVID-19 effectively reduced the of transmission risk of COVID-19 in communities.


Subject(s)
COVID-19/epidemiology , Pandemics , Adolescent , Adult , Child , China/epidemiology , Female , Humans , Male , Middle Aged , Young Adult
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