In recent years, great achievements have been made in the therapy of viral hepatitis B and viral hepatitis C, as majority of hepatitis C patients can be clinically cured.Though current antiviral therapy is still unable to eradicate hepatitis B virus in infected hepatocyte and few patients could achieve HBsAg loss or seroconversion, end-stage liver disease like cirrhosis, liver failure and hepatocellular carcinoma have been dramatically prevented.The advances in treatments have prompted the progress in laboratory diagnosis of viral hepatitis.Here we review the progress in the field.

Hepatitis E, caused by hepatitis E virus (HEV) infection, usually leads to an acute clinical course, and is the most common diagnosis among cases of acute viral hepatitis. From 2008, there have been increasing reports of chronic HEV infection in immunocompromised patients such as organ transplant recipients. Without intervention with antiviral treatment, approximately 60% of HEV infections in organ transplant recipients evolve into chronic HEV infections. Of these chronic hepatitis E patients, 10% may develop liver fibrosis and progress to liver cirrhosis. This article reviews chronic HEV infection and treatment in organ transplant recipients.
Animals ; Antiviral Agents ; therapeutic use ; Hepatitis E ; drug therapy ; virology ; Hepatitis E virus ; genetics ; isolation & purification ; physiology ; Hepatitis, Chronic ; drug therapy ; virology ; Humans ; Transplant Recipients ; Transplants ; virology

Objective:To get specific monoclonal antibodies ( mAbs) against PD-L1 which can block PD-1/PD-L1 binding, and explore the feasibility of its application on the treatment of chronic HBV infection preliminarily by in vitro and in vivo model. Methods:E. coli expression and series chromatography purification system were employed to get human and mouse PD-1/PD-L1 that had binding activity in vitro. By immunizing BALB/c mouse with purified recombination proteins of PD-L1,mAb hybridoma cell lines against PD-L1 were obtained. The reactivity with human/mice PD-L1 of individual antibody and the interaction blocking activity of the mAbs to PD-1/PD-L1 in vitro were examined by indirect chemiluminescence immune assay. Results: 8 cell lines against PD-L1 were obtained and 2 Anti-PDL1 mAbs (Ab5 &Ab6) performed strong immune activity to human/mice PD-L1 and blocking activity to PD-1/PD-L1. In the PBMC stimulation experiment of chronic HBV patient,Ab5 and Ab6 could promote theγ-IFN levels. With HBV in-fecting mice model,intravenous injections of these mAbs induced dramatically decrease of HBV DNA copies about 20 times, HBsAg levels in serum reduced to 30% of the baseline level. Conclusion:We obtained 2 PD-L1 mAbs with the reactivity to human/mice PD-L1 and blocking activity to PD-1/PD-L1. The 2 mAbs can promote T cell function in PBMC stimulation culture of chronic HBV patient, have significant antiviral effect in HBV transgenic mice and can be candidates for immunotherapy applications.

Objective To establish a mouse model of genital human papillomavirus (HPV) pseudovirion (PsV) transmission and evaluate the protective potency of HPV16 VLP vaccine.Methods HPV16 PsV with the encapsidated luciferase expressing plasmid Luc were generated from 293FT cells and purified by size-exclusion chromatography.The endpoint titers of HPV16 PsV-Luc were determined on 293FT cells, denoted as TRLU/mL.For in vivo genital challenge, mice were synchronized in a diestrus-like status by a subcutaneous injection with 0.1 μg β-estradiol and then with 3mg DepoProvera after 24 hours.Six hours prior to HPV16 PsV-Luc challenge, deeply anesthetized mice were intravaginally pretreated with 50 μL of 4%nonoxynol-9 ( N-9 ).HPV16 PsV-Luc was thoroughly mixed with 20 μL solution containing 4%carboxymethylcellulose ( CMC ) and intravaginally instilled using a positive-displacement pipette.Forty-eight hours after PsV-Luc challenge, mice were anesthetized and D luciferin was intravaginally instilled.After 3 minites, bioluminescence was measured with a cryogenically cooled Xenogen IVIS camera system.Then,the murine genital challenge model was used to determine the potency that HPV16 VLP vaccine is efficient at preventing HPV infection.Results HPV16 PsV-Luc was generated and purified from 293FT cells.HPV16 PsV-Luc was verified to containe L1 and L2 protein by Western blot.HPV 16 PsV-Luc successfully infected vaginal epithelial cells of mouse and the murine genital challenge model was established.To achieve consistent bioluminescence, the minimal dose of HPV16 PsV-Luc was 1.7 ×104 TRLU.The protective potency of HPV16 VLP vaccine was shown using this murine model.Our data showed that immune serum with over neutralizing antibody titer of 256-fold was sufficient to confer protection against HPV PsV genital infection .Conclusion The murine genital challenge model of HPV16 was successfully established, and the model is used to evaluate the potency of HPV16 VLP vaccine against in vivo genital HPV16 PsV challenge.Our model will benefit for the investigation of HPV neutralization and the potency evaluation of the HPV vaccine .

Objective To quantitatively analyze the characteristics of a panel of murine anti-human papillomavirus(HPV)11 L1-derived virus-like particle( VLP ) monoclonal antibodies ( mAbs ) and establish the mAb-based methods for antigen quality analysis.Methods A panel of 22 murine anti-HPV11 mAbs were characterized in details with their isotype, and binding affinity, conformational sensitivity were examined quantitatively in the direct binding ELISA and Western blot.The hemagglutination inhibition activity of mAbs were identified using the hemagglutination inhibition assay and the pseudovirus ( PsV ) neutralization efficiency were examined quantitatively using the PsV-based neutralization assay.The type-specific, highly conformational sensitive and neutralizing mAbs were selected to be used in the sandwich ELISA assay.Results Based on the quantitative and semi-quantitative results, six type-specific, highly conformational sensitive and neutralizing mAbs (2A2, 4A1-3, 16G7, 14A6, 9C1 and 19C7) were identified.These mAbs, along with 10D6 were screened as the capture mAb or as the detection mAb in the sandwich ELISA.Conclusion The binding affinity, conformational sensitivity and neutralization efficiency of anti-HPV11 mAbs were characterized in details.A mAb-based sandwich ELISA assay (14A6:Ag:9C12-HRP) were developed, which could be used in the in vitro potency analysis of HPV11 VLP-based vaccine.

Persistant infection of high-risk human papillomavirus (HPV) is the primary cause leading to cervical cancer, which is ranked as second cancer threatening the health of women following breast cancer.Development of HPV vaccine is very important because there is no effective therapeutics for cervical cancer.Three currently licensed HPV vaccines based on major capsid protein L1 in the foreign market confered good safety and efficacy in clinical trials, but the current price is expensive due to high cost, which limits the wide application in developing countries.So far, the vaccines have not been launced in China market.Here, we review the progress and the current status of the HPV vaccine, which will attract the readers’ interest on the forthcoming emergence of HPV vaccine in China.

The lack of effective in vitro infection model for hepatitis E virus (HEV) has greatly hindered the quantitative analysis of neutralizing titers of anti-HEV antibodies and human sera, thus impeding further studies of HEV-stimulated antibody responses and the immunological mechanisms. In order to improve this situation, the infection of HepG2 cells that are inefficient for HEV replication was continuously monitored until the viral load reached the limit of detection on day 13, the results of which confirmed the feasibility of using this cell line to establish the infection model. Then, neutralization assays of five anti-HEV murine monoclonal antibodies and serum samples collected from four HEV vaccine recipients (collected before and after vaccination) were performed by 96 multi-channel parallel infections, nucleic acid extraction, and qPCR. The results showed that the cell model can be applied for quantitative evaluation of the neutralizing capacity of different antibodies and antiserum samples from HEV vaccine recipients. In this study, we have successfully established a high-throughput in vitro HEV replication model, which will prove to be useful for the evaluation of HEV vaccines and studies of HEV epitopes.
Animals ; Antibodies, Viral ; analysis ; immunology ; Hepatitis Antibodies ; analysis ; immunology ; Hepatitis E ; immunology ; virology ; Hepatitis E virus ; chemistry ; immunology ; physiology ; High-Throughput Screening Assays ; methods ; Humans ; Mice ; Mice, Inbred BALB C ; Neutralization Tests ; methods ; Virus Replication

Objective To search for the neutralizing epitopos on hepatitis E virus (HEV) capsid besides the known neutralizing epitope (aa459-606). Methods By analysis of several strains of monoclonal antibodies against HEV capsid and their recognized epitopes, the neutralizing activity of epitope (aa394-458) at N-terminus was compared with that of an immunodominant neutralizing epitope (an459-606). Re-suits The research showed a novel potential neutralizing epitope in aa423-437 of HEV ORF2 though detec-ting and comparing the characteristics of several antibodies and corresponding determinations. The epitope is a linear non-immunodominant epitope which is different from the other neutralizing epitope in aa459-606.And the amino acids sequence of this novel epitope is conservative. Conclusion ORF2 aa423-437 is a no-vel potential neutralizing leaner epitope of HEV. It is believed that the present work adds fundamental knowl-edge to our understanding of HEV capsid domain and contributes to the prevention and control of this dis-ease.

Objective To produce human papillomavirus type 6(HPV-6)virus-like particles with Escherichia coli expression system and study its immunogenicity.Methods HPV-6 L1 gene was inserted into pmkaryotic expression vector pTO-T7 and then expressed in Escherichia coli ER2566.The HPV-6 L1 protein was purified by ammonium sulfate precipitation,ion-exchange chromatography,and hydrophobic interaction chromatography.Then the purified HPV-6 L1 self-assembled into virus-like particle after removing 1,4dithiothreitol(DTr).The morphology of the virus-like particles was investigated with dynamic light scatter and transmission electron microscopy,and the immunogenicity was determined with in vitro pseudownons neutralization as8ay.Results HPV-6 L1 was expressed in soluble form in Escherichia coli.Following the removal of DTT,purified HPV-6 L1 protein could assemble into virus-like particles as 25 am in the radius.And the animal immunization test showed HPV-6 virus-like particles can elite hish titer neutralizing antibodies.Conclusion The bacterially expressed HPV-6 L1 VLP is highly immunogenieity and easy to produce.And it can be good candidate of HPV-6 vaccine.

Objective To express the recombinant caspid of genotype 4 hepatitis E virus(HEV) ORF2. Methods HEV recombinant capsid protein D66 was expressed in E. coli, using the ORF2 fragment (aa368-606, obtained from swine bile) of genotype 4 HEV. Results The recombinant capsid proteins D66 self-assemble to be particle with a radius of 13 nm through dimeric form in neutral solution. Coated particles reacted well with sera obtained from patients during acute or recovered phase of HEV infection. Immunofluorescence and immnoblot assay suggested that D66 bound and penetrated HepG2 cell lines, and the process of attachment was blocked by sera collected from patients during acute or recovered phase of HEV infection.Conclusion Recombinant D66 particles simulate the structure at the surface of genotype 4 HEV well and specifically adhere and penetrate the host cells, which lays the foundation for the investigation of the molecular mechanism of genotype 4 HEV infection.