ABSTRACT
Objective:To clarify the differences of host immune responses at different stages of HBV infection. Methods:We constructed three HLA-A*0201/HBV tetramers with immunodominant epitopes of core18-27,polymerase 575-583 and envelope 335-343,and analyzed antigen specific CD8+ T cells and the expression of CD127 in peripheral blood mononuclear cells ( PBMCs) from patients infected with HBV using these HLA-A*0201/HBV tetramers. Results: The frequencies and expansion ability of antigen specific CD8+ T cells in most self-limited HBV infected individuals were higher than that in chronically HBV infected patients. In low copy period the frequencies of antigen specific CD8+ T cells were similar to those in immune clearance phase at a high viral load and liver damage and in immune clearance phase, which had no significant correlation with virus quantitation and ALT level. In chronic infection the ability of antigen specific CD8+ T cells proliferation was inversely proportional to the viral titer. In most self-limited HBV infected individuals the IFN-γsecretion functions of antigen specific CD8+ T cells were higher than in chronic infection,but in immune tolerance phase these cells lost the ability. HBsAg level was different at different stages after HBV infection:it was highest in immune tolerance phase,but in immune clearance phase,activity period and low copy period the correlation with HBV DNA replication gradually declined. The frequency of CD8+ CD127+ T cells in chronic HBV infection was lower than the control group and self-limited infection group,especially in immune tolerance with HBeAg+ and immune clearance phase. Conclusion: The frequencies of antigen specific CD8+ T cells are not the main determinant of immune-mediated protection in chronic HBV infection,memory antigen specific CD8+ T cells are not clear or missing,which provides the possibility for therapeutic vaccines and immunization therapy.
ABSTRACT
This study investigated the expression profiles of IL-10 gene in three human hepatoma cell lines including Huh7, HepG2, and HepG2 transfected with a plasmid containing hepatitis B virus (HBV) named HepG2.2.15. RT-PCR analysis demonstrated that IL-10 message RNA was absent in HepG2 and Huh7 cells, whereas it was present in HepG2.2.15 cells, which was consistent with ELISA result. Furthermore, except for lamivudine other antiviral treatments did not significantly decrease the HBV DNA level in HepG2.2.15 cells, while they had different effects on the expression of IL-10 protein, although stimulation by LPS had no significant effect. In addition, except for poly(I:C), the other treatments decreased the expression of IL-10 protein to different degrees, but had no significant effects on the expression of NF-κB and MyD88. Meanwhile, all treatments we used had effect on the expression of STAT1. In conclusion, IL-10 was expressed in HepG2.2.15 cells and STAT1 pathway might be involved in the regulation of IL-10 expression in HepG2.2.15 cells, but it was not the sole pathway, the exact mechanism warrants further study.
ABSTRACT
To better understand the effect of a new split variant of human asialoglycoprotein receptor (ASGPR H1b) on ASGPR ligands' binding ability, we established a functional cell line which expresses ASGPR. The full lengths of ASGPRH1a and H2c fragments from human liver were amplified by reverse transcript PCR (RT-PCR) and inserted into eukaryotic expression vector pIRES2EGFP, pCDNA3.1 (Zeo+) respectively. The recombinants were co-transfected into HeLa cells. After selection by using Neocin and Zeocin, a stably transfected cell line was established, which was designated 4-1-6. The transcription and expression of ASGPRH1a and H2c in 4-1-6 were confirmed by RT-PCR, Western blotting and immunofluorescence. The endocytosis function of the artificial "ASGPR" on the surface of 4-1-6 was tested by FACS. It was found that the cell line 4-1-6 could bind ASGPR natural ligand molecular asialo-orosomucoid (ASOR). After the eukaryotic plasmid H1b/pCDNA3.1 (neo) was transfected into cell line 4-1-6, H1b did not down-regulate the ligand binding ability of ASGPR. The eukaryotic expression plasmid H1b/pcDNA3.1 (neo) and H2c/pcDNA3.1 (neo) were co-transfected transiently into Hela cell. Neither single H1b nor H1b and H2c could bind ASOR. In conclusion, a functional cell line of human asialoglycoprotein receptor (ASGPR) which expresses both H1a and H2c stably was established. The new split variant H1b has no effect on ASGPR binding to ASOR. ASGPRH1b alone can't bind to ASOR, it yet can't form functional complex with ASGPRH2c.
ABSTRACT
Objective:To prepare and test tetrameric sH-2K~d-HBc complex for the further measurement of the specific CTL response.Methods:PE labled streptavidin with 4 biotinylated binding sites can bind to 4 biotinylated monomer to form the corresponding tetramer.Mice were immunized via different methods of genetic immunization by use of the construted pcDNA3-C plasmid to get the specific CTLs.Then our prepared tetramer was applied to stain the specific CTLs by the analysis of flow cytometry.Results:We applied our prepared tetramer to stain the cells from the experimental groups and control group.The results showed the tetramer was able to discriminate the frequencies of specific CTL induced by the three immunol methods(0.24%,0.26%,0.36% vs 0.07%,P≤0.05).This demonstrated that the prepared tetramer could bind its targets specifically and efficiently.The three immunol methods induced different levels of immune responses.Compared with the traditional muscle injection,gene gun induced weaker humoral immune response and stronger cellular immune response,and hydrodynamic injection induced the strongest humoral and cellular immune responses.Conclusion:Have successfully constructed the sH-2K~d-HBc tetramer.The techniques and methods can be used for preparation of tetramers of other types of MHCⅠ molecules.
ABSTRACT
The pathogenesis of HBsAg (+)/HBsAb (+) double positive hepatitis B virus infection was investigated by simulating HBsAg/HBsAb coexistence in vitro and establishing HBsAg/HBsAb double positive model in vivo. Eukaryotic expression plasmids PCI-SY, PCI-adw, PCI-adr, PCI-ayw, which expressed S gene product of different serotypes, were constructed and transfected into HepG2 cells. Recombinant proteins were purified from the transfected cells. At the same time, HBsAg mouse antiserum was obtained by immunizing mice with PCI-SY plasmid. HBsAg/HBsAb coexistence was simulated using these antigens and antiserum. Furthermore, the expression plasmids expressing different serotypes of S gene product including PCI-adw, PCI-adr, and PCI-ayw were injected into mice via tail vein. HBsAg and HBsAb in mice sera were tested at the first and 7th day respectively after antigen plasmids injection. Both in vitro simulation and in vivo animal models demonstrated that HBsAg antigen and HBsAb of the same serotypes could not coexist, but HBsAg antigen and HBsAb of different serotype could coexist. HBsAg/HBsAb double positive hepatitis B virus infection could be due to infection of viruses of different serotypes.
ABSTRACT
Hepatitis B virus (HBV)-specific cytotoxic T lymphocytes (CTLs) are believed to play a major role in viral clearance and disease pathogenesis during HBV infection. To clarify the differences in host immune responses between self-limited and chronic HBV infections, we constructed three HLA-A*0201/HBV tetramers with immunodominant epitopes of core18-27, polymerase 575-583 and envelope 335-343, and analyzed the HBV-specific CTLs in peripheral blood mononuclear cells (PBMCs) from patients infected with HBV. The frequencies and expansion ability of HBV-specific CD8(+) T cells in most self-limited HBV infected individuals were higher than those in chronic HBV-infected patients. HBV-specific CD8(+) T cells could be induced by in vitro peptide stimulation from chronic patients with a low level of serum HBV-DNA but not from those with a high level of serum HBV-DNA. In chronic infection, no significant correlation was found either between the frequencies of HBV-specific CD8(+) T cells and the viral load, or between the frequencies and the levels of alanine transaminase. Our results suggested that the frequencies of HBV-specific CTLs are not the main determinant of immune-mediated protection in chronic HBV infection and immunotherapeutic approaches should be aimed at not only boosting a HBV-specific CD8(+) T response but also improving its function.
ABSTRACT
Previous studies have shown that expression of the interferon-sensitive gene (ISG)I5 protease UBP43 is increased in the liver biopsy specimens of patients who do not respond to interferon (IFN)-α therapy. We hypothesized that UBP43 might hinder the ability of IFN to inhibit HBV replication. In this study, we investigated whether vector-based siRNA promoted by Hi (psiUBP43) could enhance IFN inhibiting HBV replication in cell culture. UBP43 was specifically silenced using shRNA. In HepG2.2.15 cells, the HBeAg and HBV DNA levels were significantly reduced by IFN after transfection of shRNA, imphicated that vector-based siRNA promoted by HI (psiUBP43) could enhance IFN inhibiting HBV replication in cell culture. These data suggest that UBP43 modulates the anti-HBV type I IFN response, and is a possible therapeutic target for the treatment of HBV infection.
ABSTRACT
The recombinant plasmid pCI-TSLC1 carrying TSLC1 gene was stably transfected into human hepatocellular carcinoma cell line HepG2. Cell proliferation was analyzed by MTT assay. The ability of migration was determined by transwell and FACSort flow cytometry was used to detect the cell cycle distribution and apoptosis. Western blotting revealed that H4 expressed higher amounts of TSLC1 protein than H15 and H0 did. The growth of TSLC1-transfected cells was significantly sup- pressed in vitro, and the ability of migration was reduced as well. The re-expression of TSLC1 could induce cell apoptosis. It was concluded that TSLC1 strongly inhibited the growth and ability of mi- gration of HepG2 cell line in vitro and also induced apoptosis, suggesting that TSLC1 could reduce the tumorigenicity of human hepatocellular carcinoma cell line HepG2 in vitro, which provided a ba-sis for further exploring the roles of TSLC1 in hepatocellular cellular carcinoma.
ABSTRACT
The recombinant plasmid pCI-TSLC1 carrying TSLC1 gene was stably transfected into human hepatocellular carcinoma cell line HepG2. Cell proliferation was analyzed by MTT assay. The ability of migration was determined by transwell and FACSort flow cytometry was used to detect the cell cycle distribution and apoptosis. Western blotting revealed that H4 expressed higher amounts of TSLC1 protein than H15 and H0 did. The growth of TSLC1-transfected cells was significantly suppressed in vitro, and the ability of migration was reduced as well. The re-expression of TSLC1 could induce cell apoptosis. It was concluded that TSLC1 strongly inhibited the growth and ability of migration of HepG2 cell line in vitro and also induced apoptosis, suggesting that TSLC1 could reduce the tumorigenicity of human hepatocellular carcinoma cell line HepG2 in vitro, which provided a basis for further exploring the roles of TSLC1 in hepatocellular cellular carcinoma.
Subject(s)
Apoptosis/genetics , Cell Adhesion Molecules/genetics , Cell Proliferation , Hep G2 Cells , Immunoglobulins/genetics , Neoplasm Invasiveness/genetics , Transfection , Tumor Suppressor Proteins/geneticsABSTRACT
<p><b>OBJECTIVE</b>To clarify the relationship between the loss of expression of the deleted in pancreatic carcinoma locus 4 (DPC4) proteins and the pathogenesis of biliary tract carcinoma.</p><p><b>METHODS</b>71 primary biliary tract carcinoma (BTCa), including 38 common bile duct (CBD) carcinomas, 18 gallbladder carcinomas, 15 hilar bile ducts (HBD) carcinomas were examined by immunohistochemical staining. In addition, the CBD carcinomas were divided into two groups: tumors with metastasis (M(+) group, 27 cases) and tumors without metastasis (M(-) group, 11 cases).</p><p><b>RESULTS</b>The frequency of loss of the expression of DPC4 protein was 32.8% in BTCa, 47.3% in CBD carcinoma, 11% in gallbladder carcinoma, 13% in HBD carcinoma. Comparison of the frequency of loss expression of DPC4 was significant statistical difference in CBD carcinoma versus gallbladder carcinoma and HBD carcinoma (P < 0.01). The frequency of loss expression of DPC4 was 48.1% in the M(+) group and 45.4% in the M(-) group.</p><p><b>CONCLUSION</b>There are a close relationship between pathogenesis of BTCa and inactivation of DPC4 and different frequencies of DPC4 gene alternation in various locations of the biliary tract, which are not significantly increased with tumor metastasis in BTCa.</p>
Subject(s)
Humans , Bile Duct Neoplasms , Biliary Tract , Carcinoma , DNA-Binding Proteins , Metabolism , Pancreatic Neoplasms , Smad4 Protein , Trans-ActivatorsABSTRACT
Objective:To develop a new model of evaluating histocompatibility between donor and recipient.Methods:①We harvested 15 couples of blood samples of donor and recipient in human BMT and detected histocompatibility between donor and recipient using the aboved model.The time when GVHR began was recorded.②Skin grafts of KunMing hybride mice were respectively placed on inbred mice,BALB/c and C57BL/6.And then histocompatibility between donor and recipient was detected using the model.Survival time of skin allografts was recorded.Results:The smaller differences of histocompatibility evaluated by means of the model were,the later GVHR in human BMT would happen and the longer survival time of skin allografts in mice would become.Conclusion:The model could be used to detect correctly histocompatibility between donor and recipient.