Rubella virus (RV), one of pathogens in TORCH syndrome, can lead to anisotropy of the fetus, and therefore it is of great significance to screen RV infection among women at child-bearing age. At the present, the screening of RV infection is mainly based on the ELISA method, the specificity of RV antigens is very important for ELISA tests. The antigenicity of RV is closely associated with its structural proteins, including capsid protein C, and envelope glycoproteins E1 and E2, which are important surface antigens of RV. This paper reviews the advances in the studies on the structure features, immunogenicity and recombinant proteins of the three structural proteins.
Antibodies, Viral ; analysis ; Enzyme-Linked Immunosorbent Assay ; Recombinant Proteins ; immunology ; Rubella virus ; genetics ; immunology ; Viral Core Proteins ; genetics ; immunology ; Viral Envelope Proteins ; genetics ; immunology ; Viral Structural Proteins ; genetics ; immunology

OBJECTIVETo clone the gene encoding nucleocapsid protein (NP) of hantavirus strain Z10 (HV-Z10), to construct its prokaryotic expression system as well as to establish a rNP-IgM direct capture ELISA based on HRP-labeled recombinant NP (rNP), in order to detect serum samples of patients suffering from hemorrhagic fever with renal syndrome (HFRS) and to evaluate the effects of detection.

METHODSGene encoding NP of strain HV-Z10 was amplified by PCR and then its prokaryotic expression system pET28a-Z10N-E. coli BL21DE3 was constructed, using routine genetic engineering method. SDS-PAGE was applied to measure the expression of rNP and ion-exchange plus Ni-NTA-affinity chromatography was performed to purify the recombinant product. Western blot assay was used to determine the specific immuno-reactivity of rNP while HRP-labeled rNP-IgM direct capture ELISA was established to detect the serum samples from 95 cases of confirmed HFRS patients. The detection effect was compared with that by routine HV-IgM indirect capture ELISA method.

RESULTSpET28a-Z10N-E. coli BL21DE3 was able to express rNP with high efficiency. The purified rNP only showed a single protein fragment in the gel after SDS-PAGE. HV-IgG could efficiently recognize rNP and hybridize with the recombinant protein. 94.73% (90/95) of HFRS patients' serum samples were positively confirmed by rNP-IgM direct capture ELISA, while a positive rate of 92.63% (88/95) in the same samples was confirmed by HV-IgM indirect capture ELISA. The distributions of A450 values of the serum samples detected by the two IgM capture ELISAs as well as the changes of the A450 mean values from several serum samples with different dilutions were similar.

CONCLUSIONWe successfully constructed a high efficient prokaryotic expression system of NP encoding gene of hantavirus strain HV-Z10. The rNP-IgM direct capture ELISA that established in this study could be used as a new serological test for HFRS diagnosis because of its simplicity, safety, with high sensitivity and specificity.

Blotting, Western ; Capsid Proteins ; genetics ; immunology ; metabolism ; Enzyme-Linked Immunosorbent Assay ; methods ; Humans ; Immunoglobulin M ; immunology ; Recombinant Proteins ; genetics ; immunology ; metabolism ; Viral Core Proteins ; genetics ; immunology ; metabolism

Hepatitis C virus (HCV) core protein is considered to be an attractive candidate for development of protective HCV vaccines. However, this protein may attenuate the induction of systemic immune responses due to its immunomodulatory properties. In this study, we constructed a HCV core gene-containing eukaryotic expression plamid pCI-C, and an in vivo-inducible prokaryotic expression plasmid pZW-C, and transformed the recombinant plasmids into an attenuated Salmonella typhimurium aroA strain SL7207. The resulting bacterial strains SL7207/pCI-C and SL7207/pZW-C were used to orally immunize BALB/c mice, and the immune responses specific to HCV core protein were assessed. Immunization with the recombinant bacteria SL7207/pCI-C led to a persistent drop in percentage of CD3 CD4 T cells, and induced a weak anti-core IgG production. Splenocytes from SL7207/pCI-C immunized mice developed a relatively weak proliferation response and inferior cytotoxic activity compared to those from the mice immunized with bacteria SL7207/pZW-C. Boost immunization with SL7207/ pCI-C yielded limited improvement in immune strength, while the boost with bacteria SL7207/pZW-C significantly enhanced the immune response. These results suggest that de novo synthesis of native HCV core protein may blunt the induction of immune responses. Attenuated S. typhimurium carrying HCV core protein could efficiently activate systemic cellular and humoral responses, and may be a promising strategy for the development of core-based HCV vaccines.
Animals ; Hepacivirus ; genetics ; immunology ; Mice ; Plasmids ; genetics ; Salmonella typhimurium ; genetics ; metabolism ; Vaccines, DNA ; immunology ; Viral Core Proteins ; genetics ; immunology ; Viral Hepatitis Vaccines ; genetics ; immunology

BACKGROUNDTo observe the features of serum specific IgA, IgG, IgM antibodies in the acute phase of hemorrhagic fever renal syndrome (HFRS).

METHODSThe nucleocapsid (NP) protein and glycoproteins (GP) of Hantavirus were expressed by recombinant baculovirus, and used as ELISA antigens to test 61 serial sera of 14 acute phase HFRS patients.

RESULTSSeoul like virus RNA were detected from 11 of 14 patients. An early and strong IgA, IgG and IgM antibody response to recombinant NP (rNP) was observed in almost all HFRS cases. The titers of antibody to rNP was apparently higher than that to Rgp. In the early stage, titer of IgG antibody elevated most drastically among all the three classes of antibodies to rNP, followed by IgM and IgA antibody responses. The elevation trend of IgM and IgA antibodies to rNP stayed nearly at the same level, but the IgA titers to rNP were apparently higher than that of IgM. Among the antibodies to rGP, IgA changed distinctly greater than IgG. The elevation trend of IgM could be found during first week after the onset, and the titers dropped gradually after the second week. IgM antibodies of one case who was viral RNA positive were not detected at early stage, but IgA titers were high. The only severe case of the 14 patients kept the lower IgA, IgG and IgM during the whole acute phase.

CONCLUSIONHFRS patients kept an early and strong humoral response to NP and GPs in acute phase of HFRS.IgA could be used together with IgM to improve the diagnostic accuracy.

Acute Disease ; Adult ; Antibodies, Viral ; blood ; Capsid Proteins ; genetics ; immunology ; Female ; Hantavirus ; genetics ; immunology ; Hemorrhagic Fever with Renal Syndrome ; immunology ; virology ; Humans ; Immunoglobulin Isotypes ; blood ; Male ; Viral Core Proteins ; genetics ; immunology ; Viral Envelope Proteins ; genetics ; immunology

OBJECTIVETo examine the antigenicity of hepatitis C virus (HCV) F protein and investigate serum prevalence of anti-F in HCV-infected patients.

METHODSEleven pairs of overlapping primers were used to synthesize the full-length HCV f gene, from which the truncated HCV f65 gene fragment was amplified by PCR. HCV f65 gene was then cloned into pET32a(+), and transformed into E. coli strain Plyss (DE3). This recombinant E.coli was induced by IPTG for the production of HCV F65 protein. The expressed HCV F65 protein, purified by Ni-NTA agarose, was further used in ELISA to detect serum anti-F, and to immunize rabbits for making polyclonal anti-F. The rabbit polyclonal anti-F was purified by Staphylococcus aureus protein A agarose.

RESULTSAfter recombinant pET32a(+)-f65 was constructed successfully, HCV F65 protein was expressed and purified. The purified HCV F65 protein was used as a capture antigen in ELISA to detect serum anti-F in HCV infected patients (n = 30). The result showed that the mean A450 value and the positive rate of serum anti-F were 0.125+/-0.061 and 63.3%, respectively. The rabbit-derived polyclonal anti-F reacted specifically with HCV F65 protein, of which the titer was 1:30,000.

CONCLUSIONOur expressed HCV F65 protein is of antigenicity, and can be used to determine serum anti-F. Anti-F IgG does exist in the sera of the HCV-infected patients. Moreover, the rabbit-derived polyclonal anti-F can be used to detect HCV F protein.

Animals ; Antibodies, Viral ; blood ; Hepacivirus ; genetics ; immunology ; Hepatitis C ; blood ; epidemiology ; immunology ; Hepatitis C Antigens ; blood ; immunology ; Humans ; Prevalence ; Rabbits ; Viral Core Proteins ; blood ; immunology ; Viral Envelope Proteins ; immunology

OBJECTIVETo search for and verify some common B cell epitopes in the core proteins of woodchuck hepatitis virus and human hepatitis B virus.

METHODSMonoclonal antibodies against both core proteins of woodchuck hepatitis virus (WHV) and human hepatitis B virus (HBV) were prepared by inoculating Balb/c mice with denatured recombination WHV and HBV core proteins. ELISA and immunoblotting assays for WHcAg and HBcAg were carried out by using these antibodies. Immunohistochemistry was carried out with liver tissue sections of both WHV-infected woodchucks and chronic HBV-infected patients. The epitopes were mapped with the mouse mAbs (6D1 and 1H4) by using a panel of 24 16mer overlapping peptides covering the entire WHcAg. The amino acid sequences of WHcAg and HBcAg were compared.

RESULTSCross-reactions were observed between mAbs (6D1 and 1H4) and WHcAg and between Mabs and HBcAg/HBcAg in ELISA and immunoblotting assay. Liver tissue sections of both WHV-infected woodchucks and chronic HBV-infected patients could be stained specifically by mAbs. The epitopes were mapped at aa1-8 (6D1) and aa125-140 (1H4) of the core proteins of both WHV and HBV by using ELISA assay. WHcAg and HBcAg share similar amino acids sequences at aa1-8 and aa125-140 respectively.

CONCLUSIONThe core proteins of woodchuck hepatitis virus and human hepatitis B virus share common linear B cell epitopes which span aa1-8 and aa125-140 respectively.

Animals ; Antibodies, Monoclonal ; biosynthesis ; B-Lymphocytes ; immunology ; Cell Line, Tumor ; Cross Reactions ; Epitopes, B-Lymphocyte ; immunology ; Hepatitis B Core Antigens ; immunology ; Hepatitis B Virus, Woodchuck ; genetics ; immunology ; Hepatitis B virus ; genetics ; immunology ; Humans ; Marmota ; Mice ; Viral Core Proteins ; immunology

BACKGROUNDS/AIMS: Hepatitis B virus(HBV) specific cytotoxic T lymphocyte (CTL) response is believed to play a major role in virus control and liver damage in chronic hepatitis B(CHB). We performed this study to evaluate whether HBV specific CTL could be visualized directly by tetrameric HLA-A2/core 18-27 complex(T c18-27) in the peripheral blood and liver of patients with CHB. On the basis of our results we clarified patients intrahepatic compartmentalization and correlation with HBV specific CTL and viral replication or liver damage. METHODS: We stained peripheral blood mononuclear cells of 33 HLA-A2 + and 8 HLA-A2 patients with CHB with cychrome conjugated anti-CD8 mAb and phycoerythrin conjugated T c18-27. Among these we analysed intrahepatic lymphocyte of 11 HLA-A2 + patients. We compared the frequency of T c18-27 specific CD8+ cells with serum HBV-DNA levels or alanine aminotransferase(ALT) levels. RESULTS: The frequency of circulating T c18-27 specific CD8+ cell was higher(9-101 cells per 50,000 CD8+ cells) than background level in 14 among 33 patients. The frequency of intrahepatic T c18-27 specific CD8+ cells was 12-2100 cells per 50,000 CD8+ cells in 8 out of 11 patients whose liver was obtained This was 17.4-150 times higher than circulating T c18-27 specific CD8+ cells. The frequency of circulating T c18-27 specific CD8+ cells was increased in 10 out of 18 patients with serum HBV DNA level <0.5 pg/mL and ALT < 40 IU/L. It was increased in just 4 out of 15 patients with HBV DNA level > 800 pg/mL and ALT >70 IU/L. The frequency of intrahepatic T c18-27 CTL tended to be lower in high levels of serum HBV DNA and was not correlated with liver inflammation. CONCLUSION: This study provess that if HBV-specific CTLs are barely detectable in the peripheral blood of CHB, much more HBV-specific CTLs are in the liver and most HBV-specific CTLs are infiltrated in the liver. Also, in the presence of an effective HBV specific CD8 response the inhibition of viral replication can be independent of liver damage.
CD8-Positive T-Lymphocytes/immunology ; DNA, Viral/analysis ; English Abstract ; HLA-A2 Antigen/analysis/*immunology ; Hepatitis B Virus/genetics/*immunology ; Hepatitis B, Chronic/*immunology/virology ; Human ; T-Lymphocytes, Cytotoxic/*immunology ; Viral Core Proteins/*immunology

Hepatocytes are the primary targets of the hepatitis C virus (HCV). While immunosuppressive roles of HCV core protein have been found in several studies, it remains uncertain whether core protein expressed in hepatocytes rather than in immune cells affects the CD8+ T cell response. In order to transduce genes selectively into hepatocytes, we developed a baculoviral vector system that enabled primary hepatocytes to express a target epitope for CD8+ T cells, derived from ovalbumin (OVA), with or without HCV core protein. Culture of OVA-specific CD8+ T cells with hepatocytes infected with these baculoviral vectors revealed that core protein has no effect on proliferation or apoptosis of CD8+ T cells. Our results suggest that HCV core protein does not exert its suppressive role on the CD8+ T cell immune response through expression in hepatocytes.
Viral Core Proteins/*metabolism ; Ovalbumin/genetics/immunology ; Mice ; Hepatocytes/cytology/*virology ; Green Fluorescent Proteins/genetics ; Genetic Vectors ; Cell Proliferation ; CD8-Positive T-Lymphocytes/*immunology ; Baculoviridae/genetics ; Apoptosis ; Animals

To develop a safe and broad-spectrum effective hepatitis C virus (HCV) T cell vaccine,we constructed the recombinant adenovirus-based vaccine that carried the hepatitis C virus truncated NS3 and core fusion proteins. The expression of the fusion antigen was confirmed by in vitro immunofluorescence and western blotting assays. Our results indicated that this vaccine not only stimulated antigen-specific antibody responses,but also activated strong NS3-specific T cell immune responses. NS3-specific IFN-γ+ and TNF-α+ CD4+ T cell subsets were also detected by a intracellular cytokine secretion assay. In a surrogate challenge assay based on a recombinant heterologous HCV (JFH1,2a) vaccinia virus,the recombinant adenovirus-based vaccine was capable of eliciting effective levels of cross-protection. These findings have im- portant implications for the study of HCV immune protection and the future development of a novel vaccine.
Adenoviridae ; genetics ; metabolism ; Animals ; CD4-Positive T-Lymphocytes ; immunology ; Cross Protection ; Female ; Genetic Vectors ; biosynthesis ; genetics ; Hepacivirus ; genetics ; immunology ; Hepatitis C ; immunology ; prevention & control ; virology ; Humans ; Interferon-gamma ; immunology ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins ; administration & dosage ; genetics ; immunology ; Viral Core Proteins ; administration & dosage ; genetics ; immunology ; Viral Hepatitis Vaccines ; administration & dosage ; genetics ; immunology ; Viral Nonstructural Proteins ; administration & dosage ; genetics ; immunology

To evaluate the clinical feasibility of the antibody titer against a chimeric polypeptide (named Core 518), in which a domain of Core and NS3 of hepatitis C virus (HCV) was fused, ELISA was performed in a total of 76 serum samples. Each serum was serially diluted using two-fold dilution method with distilled water into 10 concentrations. They were all positive for second generation anti-HCV assay (HCV EIA II; Abbott Laboratories). Genotyping RT-PCR, quantitative competitive RT-PCR, and RIBA (Lucky Confirm; LG Biotech) were also assayed. Anti-Core 518 antibody was detected in x 12800 or higher dilutions of sera from 35 of 43 chronic hepatitis C (81.4%) and nine of 16 hepatocellular carcinoma sera (56.3%), one of four cirrhosis (25%), 0 of four acute hepatitis C, and one of nine healthy isolated anti-HCV-positive subjects (p=0.0000). The anti-Core 518 antibody titers were well correlated with the presence of HCV RNA in serum (p=0.002). The anti-Core 518 antibody titers decreased significantly in nine of ten responders to IFN-alpha treatment. Monitoring anti-Core 518 titers may be helpful not only for differentiating the status of HCV infection among patients with various type C viral liver diseases, but also for predicting responses to IFN-alpha treatment.
Adult ; Aged ; Female ; Genotype ; Hepatitis C/immunology* ; Hepatitis C/drug therapy* ; Hepatitis C/diagnosis ; Hepatitis C/blood ; Hepatitis C Antibodies/immunology* ; Hepatitis C Antibodies/blood ; Hepatitis C Antigens/immunology* ; Hepatitis C-Like Viruses/immunology* ; Hepatitis C-Like Viruses/genetics ; Human ; Immunoblotting ; Interferon Alfa-2a/therapeutic use* ; Male ; Middle Age ; RNA, Viral/blood ; Recombinant Fusion Proteins/immunology ; Viral Core Proteins/immunology* ; Viral Nonstructural Proteins/immunology*