A Mouse Model of SARS-CoV-2 Infection and Pathogenesis.

Since December 2019, a novel coronavirus SARS-CoV-2 has emerged and rapidly spread throughout the world, resulting in a global public health emergency. The lack of vaccine and antivirals has brought an urgent need for an animal model. Human angiotensin-converting enzyme II (ACE2) has been identified as a functional receptor for SARS-CoV-2.

Upregulation of microRNA-146a by hepatitis B virus X protein contributes to hepatitis development by downregulating complement factor H.

Unlabelled: Hepatic injuries in hepatitis B virus (HBV) patients are caused by immune responses of the host. In our previous study, microRNA-146a (miR-146a), an innate immunity-related miRNA, and complement factor H (CFH), an important negative regulator of the alternative pathway of complement activation, were differentially expressed in HBV-expressing and HBV-free hepatocytes. Here, the roles of these factors in HBV-related liver inflammation were analyzed in detail.

[Study on the differences of two mouse models of hepatitis B virus infection by transduction with rAAV8-1. 3HBV].

We recently developed a mouse model of hepatitis B virus (HBV) chronic infection by intravenous (i.v.) injection with rAAV8-1.

Over-expression of uPA increases risk of liver injury in pAAV-HBV transfected mice.

Aim: To investigate the relationship between over-expression of urokinase plasminogen activator (uPA) and hepatitis B virus (HBV) related liver diseases in a transgenic mouse model.

Methods: Albumin-tetracycline reverse transcriptional activator and tetO-uPA transgenic mice were generated respectively through pronuclear injection and crossed to produce the double transgenic in-alb-uPA mice, for which doxycycline (Dox)-inducible and liver-specific over-expression of uPA can be achieved. Hydrodynamic transfection of plasmid adeno-associated virus (AAV)-1.

[Construction of HCV-producing cell model based on self-cleaving ribozyme].

Objectives: To construct a stable HCV-producing cell model for anti-HCV drug research.

Methods: The HCV-ribozyme recombinant plasmid pJFH1-Rbz was constructed to generate the exact 5' and 3' ends of HCV genomic RNA by placing two self-cleaving ribozymes at both ends of the HCV JFH-1 cDNA. The plasmid was then transfected into HepG2 cells and the resultant clones were screened with G418.

[Immunosuppressant dexamethasone can significantly extend the expression of hepatitis B virus antigens in the HBV mouse model by hydrodynamic transfection method].

To develop a HBV infection mouse model by hydrodynamic-based transfection and further to optimize the method of development of HBV infection mouse model. We first developed a construct which contained inverted terminal repeat elements (ITR) of adeno-associated virus (AAV) and 1. 3 copies of HBV genome (ayw subtype).

An easy-to-use site-directed mutagenesis method with a designed restriction site for convenient and reliable mutant screening.

Site-directed mutagenesis (SDM) has been a very important method to probe the function-structure relationship of proteins. In this study, we introduced an easy-to-use, polymerase chain reaction (PCR)-based SDM method for double-stranded plasmid DNA, with a designed restriction site to ensure simple and efficient mutant screening. The DNA sequence to be mutated was first translated into amino acid sequence and then the amino acid sequence was reversely translated into DNA sequence with degenerate codons, resulting in a large number of sequences with silent mutations, which contained various restriction endonuclease (RE) sites.

[Expression and purification of TAT-HBX-EGFP fusion protein and its transmembrane distribution in mouse].

Objective: To highly express TAT-HBX-EGFP fusion protein and study its distribution in mouse liver.

Methods: TAT-HBX-EGFP recombinant vector was constructed and fusion protein was induced by IPTG and expression in BL21; fusion protein was purified by Ni-NTA argarose, then injected into the peritoneal cavity of the mice. Distribution of fusion protein was observed by immunofluorescence.

[Expression of K18, Ser-33 and Ser-52 phosphorylated K18 in HBV infected human liver disease and its significance].

Objective: To investigate the expression of K18, Ser-33 and Ser-52 phosphorylated K18 in HBV infected human liver disease and its significance.

Methods: The expression and localization of K18 and Ser-33, Ser-52 phosphorylated K18 in healthy liver tissue, in liver tissues of patients with post-HBV infection cirrhosis and severe chronic hepatitis were detected by histochemistry.

Results: K18, Ser-33 and Ser-52 phosphorylated K18 were expressed in normal liver cells, in liver tissues of cirrhosis patients and severe chronic hepatitis cases.

[A follow up study of total IgM, IgG, nucleoprotein and spike protein antibodies against severe acute respiratory syndrome (SARS) coronavirus in patients with SARS].

Objective: To survey the dynamic changing and persistence of the special antibodies, including total IgM, IgG, nucleocapsid protein and spike protein antibodies, against severe acute respiratory syndrome coronavirus (SARS-CoV) in patients with SARS.

Methods: 146 cases, all clinically diagnosed as SARS with positive SARS-CoV IgG, were followed up. 362 serum samples were collected from the onset of the disease to 660 days afterward.

[Molecular cloning and expression of the severe acute respiratory syndrome-associated coronavirus nucleocapsid protein and its clinical application].

Objective: To clone and express nucleocapsid (N) protein of the severe acute respiratory syndrome (SARS)-associated coronavirus, and to evaluate its antigenicity and application value in the development of serological diagnostic test for SARS.

Methods: SARS-associated coronavirus N protein gene was amplified from its genomic RNA by reverse transcript nested polymerase chain reaction (RT-nested-PCR) and cloned into pBAD/Thio-TOPO prokaryotic expression vector. The recombinant N fusion protein was expressed and purified, and its antigenicity and specificity was analyzed by Western Blot, to establish the recombinant N protein-based ELISA for detection of IgG antibodies to SARS-associated coronavirus, and SARS-associated coronavirus lysates-based ELISA was compared parallelly.

A clinicopathological study of three cases of severe acute respiratory syndrome (SARS).

Aims: The severe acute respiratory syndrome (SARS) caused a large outbreak of atypical pneumonia in Beijing, China from early March 2003. We report the pathological features from three patients who died of SARS.

Methods: Autopsies were performed on three patients who died 9-15 days after the onset of the illness, and the clinical and laboratory features reviewed.

[A clinicopathological study on 3 cases of severe acute respiratory syndrome].

Objective: To study the pathological characteristics of severe acute respiratory syndrome (SARS) and its relationship to clinical manifestation.

Methods: Tissue specimens from 3 autopsy cases of diagnosed SARS were studied under microscopy and the clinical data were reviewed.

Results: The typical pathological changes of lungs were diffuse hemorrhage on surface.

Clinicopathological study on TTV infection in hepatitis of unknown etiology.

Aim: To investigate the state of infection, replication site, pathogenicity and clinical significance of transfusion transmitted virus (TTV) in patients with hepatitis, especially in patients of unknown etiology.

Methods: Liver tissues taken from 136 cases of non-A non-G hepatitis were tested for TT virus antigen and nucleic acid by in situ hybridization (ISH) and nested-polymerase chain reaction (PCR). Among them, TT virus genome and its complemental strand were also detected in 24 cases of autopsy liver and extrahepatic tissues with ISH.