Biliary atresia (BA) is one of the most serious digestive system diseases, which threatens the health of infants. Liver fibrosis is a major cause of death in children with BA. In the process of the pathogenesis of BA, virus infection can in?duce a series of immune and inflammatory reaction, result in a decrease of regulatory T cells (Treg cells) and high expression of CD14, activating a variety of inflammatory pathways and TGF-β/Smad2/3 pro-fibrogenic pathway, which produces a large number of medium damage of liver cells and bile duct cells, releases proinflammatory factor, oxygen metabolism matter and cytokines. These changes further aggravate damage of hepatobiliary system and cause the internal environment imbalance of liver parenchyma cells. The imbalance of internal environment with adaptive degeneration and necrosis in liver parenchyma cells, hepatic macrophages and gathered inflammatory cells leads to the activation of hepatic stellate cells (HSCs). HSCs can be converted into fibroblast cells, and promote the process of liver fibrosis. Immune and inflammatory lesions, pro-fibrogenic pathway are the important factors in contributing to liver fibrosis and cirrhosis of biliary atresia.

Objective To investigate the expression and function of transforming growth factor (TGF)-β1 and Smad2 in liver fibrosis of biliary atresia (BA). Methods Liver biopsy specimens were collected from autopsy (normal group, n=5), congenital biliary dilatation (CBD group, n=10), BA patients underwent Kasai procedure (early hepatic fibrosis group, n=19) and liver transplantation (transplantation group, n=11). The first three groups were collected from January 2010 to July 2014 in Tianjin Children’s Hospital, and the last group was collected from January 2013 to January 2014 in Tianjin First Central Hospital. The hematoxylin and eosin (HE) stain were used to observe the degree of liver fibrosis of four groups. Immunohistochemistry (IHC) was used to observe expressions of TGF-β1 and Smad2 in liver tissues of these samples. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to test the quantitative mRNA of TGF-β1 and Smad2 in these samples. Results Results of HE showed that no fibrosis in autopsy group, mild fiber cell hyperplasia in CBD group, severe fibrosis in Kasai group and significant pseudolobule in transplantation group. Results of IHC showed that TGF-β1 was expressed in the cytoplasm of hepatocytes, bile duct cells, lymphocytes and neutrophils. The average optical density of TGF-β1 was the highest in Kasai group compared with that of other three groups (P < 0.05). There was no significant difference in Smad2 expression in cytoplasm of hepatocytes, bile duct cells and lymphocytes between four groups (P>0.05). Results of qRT-PCR showed that both TGF-β1 mRNA and Smad2 mRNA were the highest in early hepatic fibrosis group than those of CBD group and transplantation group (P<0.017). Conclusion In early stage of BA, TGF-β1 and Smad2 promote liver fibrosis until the formation of P-P,P-C desmosome structure. However, with BA fibrosis becomes more serious, the pro-fibrogenic function of TGF-β1 and Smad2 becomes less.

Objective To investigate the expression and significance of integrin αvβ8, p38 and extracellular signal-regulated protein kinase 1/2 (ERK1/2) proteins, which are TGF-β1 pathway related regulatory protein, in liver fibrosis of children with biliary atresia (BA). Methods Fifteen cases of BA (Kasai group) and 10 cases of congenital biliary dilatation (CBD group) were collected in Tianjin Children’s Hospital. And liver biopsy specimens were collected in Tianjin first central hospital, including 10 cases of BA children who underwent liver transplantation due to liver failure after Kasai operation (liver transplantation group). The specimens of front part of the right lobe of the liver were taken for HE and immunohistochemistry (IHC) staining. The expressions ofαvβ8, p38 and ERK1/2 in liver were observed by IHC staining in three groups of liver tissues. Results HE staining showed fibroblast hyperplasia occasionally in CBD group, portal area expansion, fibrous tissue proliferation and wide spread bridging fibrosis with few pseudo lobules in Kasai group. In transplantation group, portal area was widened, the degree of fibrosis was severe and bridging fibrosis generally formed resulted in pseudo lobules widely. Imunohistochemistry showed that the expressions of αvβ8 and ERK1/2 were weakly positive, and the expression of p38 was negative in CBD group. In Kasai group, the expressions of αvβ8, p38 and ERK1/2 proteins were all strongly positive in liver cytoplasm, biliary epithelial cells and vascular endothelial cell cytoplasm. In liver transplantation group the expressions of αvβ8, p38 and ERK1/2 proteins were all strongly positive. The semi-quantitative analysis showed that the expressions levels of αvβ8, p38 and ERK1/2 were significantly higher in Kasai and liver transplantation groups than those of CBD group (P<0.05). There were no significant differences in expression levels ofαvβ8, p38 and ERK1/2 between Kasai group and transplantation group (P>0.05). Conclusion The expressions ofαvβ8, p38 and ERK1/2 are gradually increased in liver of BA with the process of fibrosis, which indicate that they may be involved in
the process of BA liver fibrosis.

Objective To evaluate GGT in combination with B ultrasound for the diagnosis of biliary atresia (BA) infants suffering from obstructive jaundice.Methods A retrospective analysis was made on 69 sick infants including 55 BAs and 14 non-BAs as identified by intraoperative cholangiography.The preoperative laboratory GGT and ultrasound data were collected and analyzed.The sensitivity,specificity,positive predictive value,negative predictive value and accuracy were compared.Results BA patients had significantly higher GGT than Non-BA patients (t =-4.164,P ＜ 0.05).The sensitivity,specificity,positive predictive value,negative predictive value and accuracy of GGT ＞ 306 U/L were 69.1％,92.9％,97.4％,43.3％,73.9％,respectively.In BA group,abnormal gallbladder was significantly associated with proadening portal vein,broadening hepatic artery compared with Non-BA patients (x2 =9.995,P ＜0.05).The accuracy of abnormal gallbladder on ultrasound was 78.3％.When two method combined for the diagnosis of BA,the sensitivity,specificity,positive predictive value,negative predictive value were 92.7％,92.9％,98.1％ and 76.5％ and accuracy can reach 92.8％.Conclusions For obstructive jaundice infants with GGT ＞ 306 U/L and abdominal gallbladder ultrasound finding intraoperative cholangiography should be carried out to make definite diagnosis of BA.

OBJECTIVETo study the therapeutic T cell vaccine for the treatment of chronic hepatitis B by improving the cellular immunization of HBsAg vaccine with the coexpression of the preS1 (1-42) and the Core (1-144) antigen of HBV in E. coli.

METHODSThe genes of HBcAg (1-144) and preS1 (1-42) were amplified and fused by PCR. This fused gene was inserted in the prokaryotic expression vector pET-11d and expressed in E. coli.

RESULTSIt was showed by SDS-PAGE that the protein molecular weight of the coexpression product was about 20 kD, 20% of all bacteria protein. The monoclonal antibodies against core and preS1 antibody could react with this fused protein by Western-blot technique respectively. The fused gene was verified by sequencing. Under the immune electron microscopy, this fused protein is typical particle of HBcAg but in an aggregated form.

CONCLUSIONThe results might aid for studying T cell immunotherapeutic vaccine for chronic hepatitis B.

DNA Primers ; Escherichia coli ; metabolism ; Gene Expression ; Hepatitis B Core Antigens ; biosynthesis ; genetics ; Hepatitis B Surface Antigens ; biosynthesis ; genetics ; Molecular Weight ; Polymerase Chain Reaction ; Protein Precursors ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; chemistry ; genetics

Objective To construct a recombinant fusion protein with pneumococcal surface pro-tein A (PspA) of Stretococcus pneumonia (SPN) familyⅠclade 1 and 2, and to analyze the immunogenici-ty of the fusion protein.Methods The gene fragments encoding theα-helix of PspA of the two clades were amplified by PCR and then inserted into the expression vector pET-27b(+) to construct the recombinant ex-pression plasmid.The transformed Escherichia coli BL21 strains carrying expression plasmid were induced by IPTG to express the recombinant protein.The titers and affinity of antibodies against PspA protein were measured by ELISA.An opsonophagocytic assay and an animal experiment were performed to evaluate the immunogenicity of the recombinant protein.Results Double enzyme cutting and gene sequencing confirmed the two purpose gene fragments were correctly expressed in the expression vector pET-27b(+).The titers of anti-PspA antibody in the serum of Kunming ( KM) mice immunized with the fusion protein were 1 ×104 . The affinity of anti-PspA antibody reached to 2×105 .The rates of recombinant PspA6B-PspA05 protein me-diated phagocytosis for SPN6B, SPN05 and SPN01 strains were 20%, 15% and 8.8%, respectively.No SPN23F strain was engulfed by macrophages upon the stimulation with PspA6B-PspA05 protein.The survival rates of mice injected with SPN05, SPN6B, SPN01 and SPN23F strains were respectively 75%, 92%, 75%and 33%upon the immunization of PspA6B-PspA05 protein.Conclusion The recombinant fusion protein PspA6B-PspA05, constructed with the PspA proteins of Stretococcus pneumonia familyⅠclade 1 and 2, was successfully expressed in the E.coli prokaryotic system with the advantage of high immunogenicity.High ti-ters of anti-PspA antibodies with high specificity were induced in KM mice upon the stimulation with Ps-pA6B-PspA05 protein.Moreover, a cross-protective immunity was induced in KM mice upon the immuniza-tion with PspA6B-PspA05 protein.

BACKGROUNDTo study to immunogenicity of recombinant HEV ORF2 protein expressed in pichia pastoris.

METHODSBALB/c mice were immunized with the recombinant HEV ORF2 protein. The ability of antiserum to bind HEV was tested using affinity-capture reverse transcription polymerase chain reaction (RT-PCR). Moreover, the recombinant protein was used to immunize BALB/c mice by different routes with different adjuvants. Serum conversion rate of anti-HEV antibody and the ELISA titer were detected.

RESULTSThe antiserum could capture native HEV for RT-PCR. As to the immunization effect, the immune response by intramuscular route was better than that of the intraperitoneal route. The protein with alum and CpG adjuvant could elicits more significant immune responses than using the alum adjuvant alone. The best way was to immunize with the protein with alum and CpG adjuvant by intramuscular route with a boosted injection on the 4th week after the first immunization. The ED50 was 0.023 microgram. This is the first report that the antibody elicited by recombinant HEV ORF2 protein expressed in pichia pastoris recognizes native HEV. High immunogenicity of this kind of ORF2 was also demonstrated by inducing strong immune response in mice with good ED50 result.

CONCLUSIONSThe high immunogenicity of this kind of HEV ORF2 may make a foundation for the development of new type of hepatitis E vaccine.

Animals ; Antibody Formation ; Female ; Hepatitis E virus ; immunology ; Mice ; Mice, Inbred BALB C ; Pichia ; genetics ; Recombinant Proteins ; genetics ; immunology ; Reverse Transcriptase Polymerase Chain Reaction ; Viral Proteins ; immunology

BACKGROUNDTo determine the antigenicity of HGV NS5 recombinant proteins expressed in E.coli.

METHODSHGV NS5a,NS5b and core/NS5b fusion genes were cloned into pThioC vector. Three expression plasmids were transformed into JM109(DE3) competent cells then expressed with induction by IPTG. Western blot and ELISA were used to determine the antigenicity after the three recombinant proteins were purified.

RESULTSAfter identification by restriction enzyme and sequencing, it was confirmed that the expressed was target proteins espected. Purified expression proteins were found strongly immunoreactive among anti HGV positive sera by Western blot and ELISA. Compared with mixed recombinant antigen (including core, NS5a synthetic peptide and NS3 recombinant proteins), in the 22 positive sera detected with mixed antigen, 68%(15/22), 90%(20/22) and 73%(16/22) were positive by P5a,P5b and Pc?5b antigens; In the 70 negative samples with mixed antigen, 7%(5/70), 1%(1/70) and 6%(4/70) were positive by P5a, P5b and Pc?5b antigens. The positive alone was found among RTPCR positive specimen using these recombinant antigens.

CONCLUSIONSNS5 gene expressed in E.coli?which couldn't be covered with other regions of antigens was one of the essential epitopes to HGV immunologic diagnosis.

Antibodies, Viral ; blood ; Antigens, Viral ; blood ; Epitopes ; immunology ; GB virus C ; genetics ; immunology ; Humans ; Plasmids ; genetics ; Recombinant Proteins ; biosynthesis ; immunology ; Viral Nonstructural Proteins ; genetics ; immunology

BACKGROUNDTo obtain thermal stable, soluble, biologically active hepatitis E virus recombinant antigen using thioredoxin fusion expression system.

METHODSHEV ORF2 gene fragment (6964-7126 nt) was inserted into thioredoxin fusion expression vector pThioHisA. The recombinant plasmid was transformed into E. coli BL21 strain. After induction with IPTG, cells were lysed and the supernatant was subjected to 80 degree treatment for 10 minutes. After centrifugation, the supernatant was tested by ELISA.

RESULTSSDS-PAGE analysis showed the thioredoxin. HEV fusion protein was highly expressed and was thermally stable, soluble. HEV specific ELISA confirmed this fusion protein possessing HEV specific antigenicity.

CONCLUSIONSUsing thioredoxin fusion expression system, a soluble, thermal stable, biologically active HEV recombinant antigen was successfully expressed.

Antigens, Viral ; biosynthesis ; genetics ; Gene Expression ; Genetic Vectors ; Hepatitis E virus ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Thioredoxins ; genetics ; Viral Proteins ; biosynthesis ; genetics