The cytokine pattern on viral antigen recognition is believed to exert a profound influence on the resolution of viral infections and viral clearance. This study was initiated to investigate whether a cytokine imbalance oriented toward Th2 type response plays a role in chronic hepatitis B. Cytokine profiles of peripheral blood mononuclear cells associated with chronic hepatitis B were analysed by RT-PCR. Upon HBsAg stimulation, expression of IFN-gamma, IL-2, IL-4, and IL-10 was detected in 41%, 8%, 41%, and 50% of the patients, respectively. Among these cytokines, the expression of IFN-gamma was associated with high levels of serum AST/ALT. However, we could not prove that Th2 type cytokines had a protective effect on hepatocytes. Upon HBxAg stimulation, there was no recognizable association of cytokine patterns with AST/ALT levels. In conclusion, production of a Th1 cytokine, IFN-gamma, by HBsAg-reactive cells was associated with hepatocyte damage in chronic hepatitis B, while no counteracting effect of Th2 cytokines produced by those cells was observed.
Cytokines/genetics ; Cytokines/biosynthesis* ; Hepatitis B Surface Antigens/pharmacology ; Hepatitis B Surface Antigens/immunology* ; Hepatitis B, Chronic/immunology* ; Human ; Interferon Type II/genetics ; Interferon Type II/biosynthesis ; Leukocytes, Mononuclear/immunology ; Liver/cytology ; Recombinant Fusion Proteins/pharmacology ; Recombinant Fusion Proteins/immunology ; Th1 Cells/immunology* ; Th1 Cells/drug effects ; Th2 Cells/immunology* ; Th2 Cells/drug effects ; Trans-Activators/pharmacology ; Trans-Activators/immunology*

Hepatitis B virus (HBV) infection disrupt the innate immunity response, which may play an important role in the chronic mechanism, while retinoic acid-induced gene I (RIG-I) mediated signaling pathway is one of the most important channel in the innate immunity. HBx and HBV polymerase may disrupt RIG-I mediated signaling pathway. The recent advances about HBV and RIG-I are reviewed in this article.
DEAD Box Protein 58 ; DEAD-box RNA Helicases ; metabolism ; Gene Products, pol ; metabolism ; Hepatitis B ; immunology ; Humans ; Immunity, Innate ; immunology ; Signal Transduction ; Trans-Activators ; metabolism

The expression profile in the mouse hepatitis B virus X (HBx)-transfected model was investigated in order to lay a foundation for further study on the implication of cytokines expression in hepatitis B virus (HBV) infection. Hydrodynamic injection method via the tail vein was used to establish the animal HBx-transfected model. By using microassay, the differential expression of gene in each group was analyzed, which was further confirmed by using real-time PCR and semi-quantitative PCR. Most of chemokine genes such as Ccl2, Ccl5, Ccl9, MIG and IP-10 were up-regulated in the HBx-transfected mouse model versus the control mice, which was coincided with the microarray results. Western blotting and immunohistochemistry were applied to detect the expression of MIG and IP-10 in the liver tissues. Simultaneously, ELISA was adopted to measure the content of IFN-γ in the liver tissues. DNA microassay revealed that the expression of 611 genes changed in HBx-transfected mice as compared with that in pCMV-tag2B-transfected mice, and most of the screened chemokines were up-regulated (including MIG and IP-10). Additionally, IFN-γ protein levels were increased by 20.7% (P<0.05) in pCMV-tag2B-HBx-transfected mice as compared with the untreated mice. IFN-γ protein levels were reduced by 53.9% (P<0.05) in pCMV-tag2B-transfected mice as compared with the untreated mice, which was consistent with the up-regulation of MIG and IP-10. It was suggested HBx transfection could induce the expression of MIG and IP-10 in the liver tissues, which might play the roles in HBV-related liver immunity and cytokines-mediated antiviral effect.
Animals ; Chemokine CXCL10 ; immunology ; Chemokine CXCL9 ; immunology ; Cytokines ; immunology ; DNA, Viral ; genetics ; Hepatitis B ; genetics ; immunology ; virology ; Hepatitis B virus ; genetics ; immunology ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Trans-Activators ; genetics ; Transfection ; methods

The MHC class II transactivator (CIITA) is the master transcriptional regulator of genes involved in MHC class II restricted antigen presentation. Previously we suggested another role of CIITA in Th1/Th2 balance by demonstrating that forced expression of CIITA in murine T cells repressed Th1 immunity both in vitro and in vivo. However, the results were contradictory to the report that CIITA functioned to suppress the production of Th2 cytokine by CD4+T cells in CIITA deficient mice. In this study, we investigated the influence of constitutive expression of CIITA in T cells on Th2 immune response in vivo using murine experimental colitis model. In the dextran sodium sulfate-induced acute colitis, a disease involving innate immunity, CIITA transgenic mice and wild type control mice showed similar progression of the disease. However, the development of oxazolone-induced colitis, a colitis mediated by predominantly Th2 immune response, was aggravated in CIITA-transgenic mice. And, CD4+T cells from the mesenteric lymph node of CIITA-transgenic mice treated with oxazolone exhibited a high level of IL-4 secretion. Together, these data demonstrate that constitutive expression of CIITA in T cells skews immune response to Th2, resulting in aggravation of Th2-mediated colitis in vivo.
Trans-Activators/*physiology ; Th2 Cells/*immunology ; T-Lymphocytes/*metabolism ; Oxazolone/pharmacology ; Nuclear Proteins/*physiology ; Mice, Transgenic ; Mice, Inbred C57BL ; Mice ; Interleukin-4/biosynthesis ; Colitis/*etiology ; Animals

OBJECTIVEThis paper studied the effect of RNaseP against CIITA on repressing class II MHC (MHCII) expression.

METHODSIt was constructed that M1-RNA with guide sequences (GS), recognizing the 629 site of CIITA (M1-629-GS), by PCR from pTK117 plasmid, then was cloned into psNAV (psNAV-M1-629-GS). CIITA target gene was obtained from Raji cell by RT-PCR, and then inserted into pGEM-7zf (+) (pGEM-800). psNAV-M1-629-GS and pGEM-800 were transcribed and then mixed up and incubated in vitro. Stable transfectants of hepatocyte with psNAV-M1-629-GS by nanometer were tested for MHCII induction by recombinant human interferon-gamma (IFN-gamma). mRNA abundance of CIITA was measured by RT-PCR.

RESULTSIt showed that M1-629-GS could exclusively cleave pGEM-800 that formed a base pair with the GS. When induced with IFN-gamma, the expression of HLA-DR, -DP, -DQ on psNAV-M1-629-GS+ hepatocyte was (1.01+/-0.51)%, (4.37+/-1.28)%, (1.98+/-0.42)% respectively, was down-modulated 90.65%, 89.11% and 65.32% compared with control, while the mRNA content of CIITA reduced significantly (P<0.01).

CONCLUSIONM1-629-GS could effectively repress MHCII expressing through cleaving CIITA mRNA. These results provided insight into the future application of it as a new nucleic acid drug against the rejection of hepatic transplantation.

Graft Rejection ; prevention & control ; Histocompatibility Antigens Class II ; analysis ; Humans ; Liver Transplantation ; immunology ; Nuclear Proteins ; genetics ; RNA, Messenger ; analysis ; Ribonuclease P ; pharmacology ; Trans-Activators ; genetics

OBJECTIVEDifferent from primary membranous nephropathy, hepatitis B virus associated membranous nephropathy (HBV-MN) shows lower deposits of membrane attack complex (C5b-9) in glomerular subepithelium. The causes of relatively low complement activation in this disease remain unclear. The aim of this study was to investigate the influence of hepatitis B x protein (HBx) on the expression of CD59 and Crry in mouse podocytes.

METHODCultured mouse podocytes were divided into adenovirus vector hepatitis B virus X gene (Ad-HBx) transfected group (Ad-X group), blank podocytes group (B group) and adenovirus vector transfected group (Ad group). CD59 and Crry mRNA expression were assayed by semiquantitative RT-PCR. CD59 and Crry expression were tested by flow cytometry. The effect of HBx on complement activation was evaluated with MTT method. And then, the effects of P38MAPK, PI-3K and ERK1/2 pathway inhibitors (SB203580, LY294002, U0126) and DMSO on CD59 and Crry expression were respectively detected by flow cytometry.

RESULTProteins CD59 and Crry expression rates (%) in group B, Ad group and Ad-X group were 17.71 ± 3.81, 18.29 ± 3.36 and 45.7 ± 9.01; 18 ± 2.31, 21.78 ± 2.01 and 47.45 ± 9.95, respectively. Compared with group B, CD59 and Crry expression in group Ad was not significantly different (P values for both > 0.05), but CD59 and Crry protein expression in Ad-X group was significantly higher than that in groups B and Ad (P values for both < 0.005); CD59 and Crry gene expression in group Ad was not significantly different from that in group B (P values for both > 0.05). However, CD59 and Crry gene expression of Ad-X group was significantly higher than that in groups B and Ad (P values for both < 0.05). Flow cytometry detected CD59 protein expression rates (%) were 17.35 ± 1.24, 46.19 ± 9.77, 43.03 ± 6.83 and 40.04 ± 6.39 and Crry protein expression rates (%) were 18.14 ± 3.56, 31.95 ± 1.68, 31.95 ± 1.69 and 37.14 ± 3.92 after SB203580, LY294002, U0126 and DMSO were added to Ad-X group respectively. P38 pathway inhibition resulted in significantly lower CD59 and Crry expression than Ad-X group (P values for all < 0.005), but PI-3K, ERK1/2 pathway inhibitors and DMSO had no significant effect on the expression of CD59 and Crry (P values for all > 0.05). The inhibition rates of cell lysis were significantly higher in Ad-X group than in groups B and Ad at each serum dilution point (P values for all < 0.05), while groups B and Ad had no significant difference in cell viability.

CONCLUSIONHBx can up-regulate CD59 and Crry expression in podocytes through activating P38 pathway, resulting in decreased complement activation, which may facilitate latent HBV infection in podocytes and play a role in development of hepatitis B virus associated glomerulonephritis (HBV-GN).

Animals ; CD59 Antigens ; metabolism ; Cells, Cultured ; Mice ; Podocytes ; immunology ; metabolism ; Receptors, Complement ; metabolism ; Trans-Activators ; metabolism ; p38 Mitogen-Activated Protein Kinases ; metabolism

Replication of the hepatitis B virus is suppressed by deficiency of the X protein. Although several molecules that block cellular targets of X protein reduce the production of hepatitis B virus progeny, the effect of a specific inhibitor of X protein on viral replication has not been investigated. To block X protein specifically, we adopted an intracellular expression approach using H7 single chain variable fragment (H7scFv), an antibody fragment against X protein. We previously demonstrated that cytoplasmic expression of H7scFv inhibits X protein-induced tumorigenicity and transactivation. In this study, intracellular H7scFv expression inhibits reporter gene transactivation but not viral replication determined by endogenous hepatitis B virus polymerase activity assay and real-time PCR. Our findings imply that intracellular expression of antibody fragment against X protein may not be an alternative therapeutic modality for inhibition of hepatitis B virus replication.
Virus Replication/*drug effects ; Trans-Activators/*antagonists & inhibitors/immunology ; Immunoglobulin Variable Region/genetics/metabolism/*pharmacology ; Hepatitis B virus/*drug effects/physiology ; Hepatitis B e Antigens/metabolism ; Cell Line

OBJECTIVETo develop a tight tetracycline-controlled HCV-C double transgenic mouse model.

METHODSBy crossbreeding of ApoE-rtTA-tTS transgenic mice with TRE-HCV-C transgenic mice, the double transgenic mice were produced in the F1 generation. The presence of HCV-C and tTS gene in the F1 generation was confirmed by PCR, followed by further identification and quantification of the transgene using Southern blot hybridization. The expression of HCV-C in the liver of the mouse model was detected immunohistochemically.

RESULTS AND CONCLUSIONTwo transgenic mice were obtained, which contained ApoE-rtTA-tTS and TRE-HCV-C genes in the genome. Five founders contained HCV-C gene as confirmed by PCR and Southern blot hybridization. The tight tetracycline-controlled system may facilitate further study of HCV-C gene expression and gene therapy of hepatic cellular carcinoma.

Animals ; Apolipoproteins E ; genetics ; Blotting, Southern ; Breeding ; Crosses, Genetic ; Female ; Gene Expression Regulation, Viral ; drug effects ; Hepacivirus ; genetics ; immunology ; Hepatitis C Antigens ; genetics ; immunology ; Male ; Mice ; Mice, Transgenic ; Polymerase Chain Reaction ; Tetracycline ; pharmacology ; Trans-Activators ; genetics ; Viral Core Proteins ; genetics

OBJECTIVETo observe Smads protein expression in lung tissue of quartz exposed mice and to explore its association with pulmonary fibrosis in silicosis.

METHODSThe experimental mice were divided into control and quartz groups. 0.2 g/kg weight of quartz was injected intratracheally in quartz group. Samples were collected at the 1st, 3rd, 5th, 7th, 14th and 28th day after injection. Immunohistochemical methods with quantitative image analysis were used to assay the protein expression of transforming growth factor beta(1) (TGF-beta(1)), Smad 2/3, Smad 4, and Smad 7 protein levels. Protein expression level is presented by positive unit (PU).

RESULTSSmad 2/3 protein expression increased from day 3, reaching its peak level in day 14 [(42.2 +/- 2.4) PU], and decreased gradually. The elevation of Smad 4 protein level began from day 5, and the highest degree came into day 14 [(40.0 +/- 1.8) PU], decreased thereafter. The expression of Smad 7 presented a decreasing tendency at the beginning and reaching the lowest level in day 14 [(33.5 +/- 3.3) PU]. It seemed to elevate in day 28, but was still lower than the controls. There were positive correlation between Smad 2/3, Smad 4 and TGF-beta(1) (r = 0.91, r = 0.71, respectively, P < 0.05) and also between Smad 2/3 and hydroxyproline contents of lung tissue (r = 0.85, P < 0.05) except Smad 7.

CONCLUSIONSmad protein may have certain association with pulmonary fibrosis in silicosis.

Animals ; DNA-Binding Proteins ; immunology ; metabolism ; Lung ; metabolism ; Male ; Mice ; Mice, Inbred Strains ; Pulmonary Fibrosis ; chemically induced ; metabolism ; Quartz ; toxicity ; Smad2 Protein ; Smad3 Protein ; Smad4 Protein ; Smad7 Protein ; Trans-Activators ; immunology ; metabolism ; Transforming Growth Factor beta ; metabolism

The present study was purposed to investigate the relation and difference of expression phase between class II transactivator (CIITA) and HLA-DR antigens after IFN-gamma induction, and the inhibition of CIITA and HLA-DR by STAT1-alpha antisense oligonucleotides (STAT1-alpha AS); and to explore the potential effect and significance of CIITA and STAT1-alpha AS in transplantation immunity. T lymphocytes from peripheral blood of healthy subjects were incubated with IFN-gamma at different doses. RT-PCR was used to detect CIITA mRNA and Western blot was used to analyze HLA-DR antigen. Then the optimum dose of IFN-gamma was chosen for the experiment. CIITA mRNA and HLA-DR antigen were detected at various time points. Different doses of STAT1-alpha AS and sense oligonucleotides (STAT1-alpha S) were added to T lymphocytes followed by IFN-gamma. After incubation with IFN-gamma, the expression of CIITA mRNA and HLA-DR was detected once again. The results showed that CIITA mRNA was detectable at 5 hours after IFN-gamma incubation and reached the peak at 14 hours, then declined, but the CIITA mRNA was still found at 23 hours. HLA-DR antigen was detectable at 28 hours after IFN-gamma incubation and reached a peak at 52 hours, then declined. CIITA mRNA expression was positively correlated to HLA-DR expression, and was earlier than the latter. The expression of CIITA mRNA in the AS groups was significantly lower than that in the control group after 5 micromol/L, 10 micromol/L and 20 micromol/L STAT1-alpha AS treatment (P < 0.01). The expression of CIITA mRNA in the S groups was higher than that in the AS groups (P < 0.01), but there was no significant difference between the S group and the control group. The expression of HLA-DR antigen was significantly inhibited by STAT1-alpha AS, and the expression level of HLA-DR protein in the AS group was about 64.3% of that in the control group (P < 0.01), while there was no significant difference in HLA-DR expression between the S group and the control group. The changes in HLA-DR expression were similar to those in CIITA expression after STAT1-alpha AS treatment. It is concluded that CIITA expression is positively correlated with HLA-DR expression, and was detectable earlier than that of latter after IFN-gamma incubation. Stat1-alpha antisense oligonucleotides may have a sequence-specific inhibiting effect on the expression of CIITA and HLA-DR antigen after IFN-gamma incubation in vitro culture, and can prevent T lymphocyte activation. CIITA may play an important role in pathogenesis of transplantation immunity.
Cells, Cultured ; HLA-DR Antigens ; biosynthesis ; genetics ; Humans ; Interferon-gamma ; pharmacology ; Nuclear Proteins ; biosynthesis ; genetics ; Oligonucleotides, Antisense ; antagonists & inhibitors ; RNA, Messenger ; biosynthesis ; genetics ; STAT1 Transcription Factor ; antagonists & inhibitors ; T-Lymphocytes ; cytology ; Trans-Activators ; biosynthesis ; genetics ; Transplantation Immunology ; immunology