Survival of SARS-CoV-2 in artificial seawater and on the surface of inanimate materials.

There is a potential risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread through human contact with seafood and the inanimate materials contaminated by the virus. In this study, we examined the stability of the virus in artificial seawater (ASW) and on the surface of selected materials. SARS-CoV-2 (3.

Neutralizing SARS-CoV-2 by dimeric side chain-to-side chain cross-linked ACE2 peptide mimetics.

We present the finding of a dimeric ACE2 peptide mimetic designed through side chain cross-linking and covalent dimerization. It has a binding affinity of 16 nM for the SARS-CoV-2 spike RBD, and effectively inhibits the SARS-CoV-2 pseudovirus in Huh7-hACE2 cells with an IC of 190 nM and neutralizes the authentic SARS-CoV-2 in Caco2 cells with an IC of 2.4 μM.

Advancements in detection of SARS-CoV-2 infection for confronting COVID-19 pandemics.

As one of the major approaches in combating the COVID-19 pandemics, the availability of specific and reliable assays for the SARS-CoV-2 viral genome and its proteins is essential to identify the infection in suspected populations, make diagnoses in symptomatic or asymptomatic individuals, and determine clearance of the virus after the infection. For these purposes, use of the quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) for detection of the viral nucleic acid remains the most valuable in terms of its specificity, fast turn-around, high-throughput capacity, and reliability. It is critical to update the sequences of primers and probes to ensure the detection of newly emerged variants.

Luteolin-7--Glucoside Present in Lettuce Extracts Inhibits Hepatitis B Surface Antigen Production and Viral Replication by Human Hepatoma Cells .

Hepatitis B virus (HBV) infection is endemic in Asia and chronic hepatitis B (CHB) is a major public health issue worldwide. Current treatment strategies for CHB are not satisfactory as they induce a low rate of hepatitis B surface antigen (HBsAg) loss. Extracts were prepared from lettuce hydroponically cultivated in solutions containing glycine or nitrate as nitrogen sources.

Clinical significance of the ubiquitin ligase UBE3C in hepatocellular carcinoma revealed by exome sequencing.

Unlabelled: Virus-induced hepatocarcinogenesis involves a series of histological developmental processes with the stepwise acquisition of several genetic changes that are necessary for the malignant transformation of hepatocytes. Although genetic alterations are known to be involved in the pathogenesis of hepatocellular carcinoma (HCC), little is known about the contributions of specific genes to this process. To gain insight into the genetic alterations involved in the neoplastic evolution from chronic hepatitis B virus infection to dysplastic nodules (DN) to HCC, we captured and sequenced the exomes of four DNA samples: one DN sample, two HCC samples, and one control peripheral blood sample from a single HCC patient.

Immunization with HBsAg-Fc fusion protein induces a predominant production of Th1 cytokines and reduces HBsAg level in transgenic mice.

Background: The Fc receptor associated pathway might improve the immune responses against hepatitis B virus (HBV) as previously described by us. In addition, the Flt3 ligand (FL) has been reported to potentiate antigen presenting cells in vivo and may act as a potential adjuvant to boost antigen-specific immune responses. In this study, the immune efficacies of a set of fusion proteins of HBsAg and Fc and/or FL were evaluated in HBsAg transgenic mice.

[Cloning and expression of Streptococcus salivarius urease gene in Escherichia coli].

Objective: To clone Streptococcus salivarius (Ss) 57. I urease gene, which can express ureolytic activity in Escherichia coli (Ec) without adding extra nickel ions.

Methods: Urease gene was cloned by polymerase chain reaction in three separate parts.

Transcriptional analysis of immune-related genes in dendritic cells from hepatitis B surface antigen (HBsAg)-positive transgenic mice and regulation of Fc gamma receptor IIB by HBsAg-anti-HBs complex.

To study the gene expression profiles in dendritic cells (DCs) from a hepatitis B surface antigen (HBsAg) positive host, transcriptional analysis of bone marrow -derived DCs from a lineage of HBsAg transgenic mice (#59) was compared to DCs from normal mice. Among the immune-related genes, 12 were up-regulated, and 14 were down-regulated in transgenic mice relative to those of normal mice. The up-regulated genes include genes encoding immunoglobulin, histocompatibility 2 (K region), and several complement component genes, while the down-regulated genes include the TAP1 (transporters associated with antigen processing gene-1), interferon induced gene (Ifi203), chemokine (C-X-C) ligands and leukocyte-immunoglobulin-like genes, Lck-interacting transmembrane adaptor genes and histocompatibility 2 (Q region and T region).

Development of novel therapeutics for chronic hepatitis B.

Chronic infection of hepatitis B virus (HBV) presents one of the serious public health challenges worldwide. Current treatment of chronic hepatitis B (CHB) is limited, and is composed of interferon and nucleoside/nucleotide reverse transcriptase inhibitors (NRTI). Interferon is poorly tolerated and is only responsive in a small fraction of CHB patients and NRTIs often face the problem of emergence of drug resistance during long-term treatment.

Serum HBeAg sero-conversion correlated with decrease of HBsAg and HBV DNA in chronic hepatitis B patients treated with a therapeutic vaccine.

Currently, there are various approaches for developing therapeutic vaccines for chronic hepatitis B patients. Previously, an antigen-antibody-based therapeutic vaccine (YIC) has been conducted in a double-blind placebo controlled phase IIb clinical trial in 242 chronic hepatitis B patients. At the end of follow-up for 24 weeks, HBeAg sero-conversion rate was 21.

A double-spliced defective hepatitis B virus genome derived from hepatocellular carcinoma tissue enhanced replication of full-length virus.

In hepatitis B virus (HBV) replication cycle, pregenomic RNA undergoes splicing and the reverse transcribed defective genomes can be packaged and released. Various types of spliced defective HBV genomes have been isolated from the sera and liver tissues of viral hepatitis B patients. To explore the functions of a 2.

Modulation of transcriptional corepressor activity of prospero-related homeobox protein (Prox1) by SUMO modification.

Prospero-related homeobox protein (Prox1) plays essential roles in the development of many tissues and organs. In the present study, we show that Prox1 is modified by the small ubiquitin-like protein SUMO-1 in cultured cells. Mutation analysis identified at least four potential sumoylation sites within the repression domain of Prox1.

Gene-expression profiles of a hepatitis B small surface antigen-secreting cell line reveal upregulation of lymphoid enhancer-binding factor 1.

The genome of hepatitis B virus (HBV) consists of four open reading frames, encoding the envelope proteins (Pre-S/S), the core proteins (Pre-C/C), the polymerase (P) and the transactivating X protein (X). In the sera of HBV-infected patients, hepatitis B surface antigen (HBsAg) particles without the viral genome can outnumber virions by more than 1000-fold. To analyse the interactions between HBsAg and host cells, global gene-expression profiles of a small HBsAg (SHBs)-secreting stable cell line (HepG2-S-G2) and its counterpart control cell line (HepG2-Neo-F4) were compared.

Identification and characterization of peptides that interact with hepatitis B virus via the putative receptor binding site.

A direct involvement of the PreS domain of the hepatitis B virus (HBV) large envelope protein, and in particular amino acid residues 21 to 47, in virus attachment to hepatocytes has been suggested by many previous studies. Several PreS-interacting proteins have been identified. However, they share few common sequence motifs, and a bona fide cellular receptor for HBV remains elusive.

Expression of mouse liver receptor homologue 1 in embryonic stem cells is directed by a novel promoter.

Liver receptor homologue 1 (LRH-1) plays important roles in many physiological processes and embryogenesis. However, little is known about the developmental regulation of lrh-1 expression. We identified a novel transcript of mouse lrh-1 (mlrh-1v2) from embryonic stem (ES) cells.

Generation of transgenic mice with liver-specific expression of human nuclear receptor nr5a2.

Human nuclear receptor hb1 f(nr5a2) was cloned and characterized as a novel member of the Ftz-F1 (nr5a) nuclear receptor subfamily,whose its biological function remained largely unidentified. The aim of this study was to establish transgenic mouse model that specifically expressed hB1F in the liver to faciliate the functional study of hB1F. hb1f cDNA was placed downstream of mouse albumin gene enhancer/promoter to construct a liver-specific hb1f expression vector.

Screening for PreS specific binding ligands with a phage displayed peptides library.

Aim: To construct a random peptide phage display library and search for peptides that specifically bind to the PreS region of hepatitis B virus (HBV).

Methods: A phage display vector, pFuse8, based on the gene 8 product (pVIII) of M13 phage was made and used to construct a random peptide library. E.

Expression and purification of the complete PreS region of hepatitis B Virus.

Aim: To express the complete PreS region of HBV in E.coli with good solubility and stability, and to establish an effective method for purification of the recombinant PreS protein.

Methods: The complete PreS region (PreS1 and PreS2) was fused into a series of tags including glutathione S-transferase (GST), dihydrofolate reductase (DHFR), maltose binding protein (MBP), 6x histidine, chitin binding domain (CBD), and thioredoxin, respectively.

Synthetic peptides derived from SARS coronavirus S protein with diagnostic and therapeutic potential.

The spike (S) protein of severe acute respiratory syndrome coronavirus (SARS-CoV) is an important viral structural protein. Based on bioinformatics analysis, 10 antigenic peptides derived from the S protein sequence were selected and synthesized. The antigenicity and immunoreactivity of all the peptides were tested in vivo and in vitro.

Expression, purification and sublocalization of SARS-CoV nucleocapsid protein in insect cells.

The causative agent of severe acute respiratory syndrome (SARS) is a previously unidentified coronavirus, SARS-CoV. The nucleocapsid (N) protein of SARS-CoV is a major viral protein recognized by acute and early convalescent sera from SARS patients. To facilitate the studies on the function and structure of the N protein, this report describe the expression and purification of recombinant SARS-CoV N protein using the baculovirus expression system.

The spike protein of severe acute respiratory syndrome (SARS) is cleaved in virus infected Vero-E6 cells.

Spike protein is one of the major structural proteins of severe acute respiratory syndrome-coronavirus. It is essential for the interaction of the virons with host cell receptors and subsequent fusion of the viral envelop with host cell membrane to allow infection. Some spike proteins of coronavirus, such as MHV, HCoV-OC43, AIBV and BcoV, are proteolytically cleaved into two subunits, S1 and S2.

Gene expression profile in liver of hB1F transgenic mice.

Aim: To analyze the tissue morphologic phenotype and liver gene expression profile of hB1F transgenic mice.

Methods: Transgene expression was analyzed with RT-PCR and Western blotting. For one of the transgenic mouse lines, tissue expression pattern of the transgene was also examined with immunochemical methods.

Expression of hepatitis C virus envelope protein 2 induces apoptosis in cultured mammalian cells.

Aim: To explore the role of hepatitis C virus (HCV) envelope protein 2 (E2) in the induction of apoptosis.

Methods: A carboxyterminal truncated E2 (E2-661) was transiently expressed in several cultured mammalian cell lines or stably expressed in Chinese hamster ovary (CHO) cell line. Cell proliferation was assessed by 3H thymidine uptake.

Characterization of the 3a protein of SARS-associated coronavirus in infected vero E6 cells and SARS patients.

Proteomics was used to identify a protein encoded by ORF 3a in a SARS-associated coronavirus (SARS-CoV). Immuno-blotting revealed that interchain disulfide bonds might be formed between this protein and the spike protein. ELISA indicated that sera from SARS patients have significant positive reactions with synthesized peptides derived from the 3a protein.