Research progress towards interferon stimulated genes and its clinical signifi-cance / 中国免疫学杂志

Interferon (IFN) acts on the surface of the target cell receptors and activate the expression of interferon stimulated genes(interferon stimulated genes,ISGs) through a series of signal transduction.ISGs have antiviral and immunomodulation and other biological functions,indicating ISGs are important molecules for interferon to function and have some potential clinical significance.A large number of research results showed that ISGs may predict the antiviral effect of IFN-α;specific expression of ISGs in patients with autoimmune diseases in vivo may be used as a new biomarker for clinical diagnosis of the diseases;ISGs may act as a new target for cancer treatment and have other potential applications.This review mainly focuses on the induction,the biological functions like antiviral effects and the potential clinical significance of ISGs.

Surveillance for occult HBV infection and HBsAg variants in blood donors / 病毒学报

Occult hepatitis B virus (HBV) infection status of blood donors in a southern city in China was investigated by immunological assays and nucleic acid testing. Overall, 17 (0.19%, 95% CI: 0.11%-0.30%) of the 9023 HBsAg negative samples were found to be positive for the presence of HBV DNA. "A" epitope sequences were obtained from 14 among them. Mutation(s) in aa124-aa147 existed in 6 (42.9%, 6/14) samples and 4 (66.7%, 4/6)were G145R mutation. Ratio of genotype C in occult donors (10/17) was statistically higher than HBs-positive donors (0/15, P<0.01), which implied that HBV genotype C leaded to occult infection more easily.

Quantitation of HTLV-I proviral load using real-time quantitative PCR with Taqman MGB probe / 病毒学报

A quantitative real-time PCR assay was developed to measure the proviral load of human T-lymphotropic virus type I (HTLV-I) in peripheral blood. The technology utilizes special primers and Taqman MGB fluorescence probe to measure amplification products from the gag-pro-pol polyprotein gene of HTLV-I. HTLV-I copy number was normalized to the amount of cellular DNA by quantitation of the beta-actin gene, The amplification system was sensitive to detect 5 copy/microL. The standard curve had a good linearity when the quantity for the gene was between 10(3) and 10(7) copy/microL (R2 = 0.999). Good reproducibility was observed in each intra- and inter-assay. We also measured proviral load in peripheral blood in 12 HTLV-I seropositive former blood donors. Proviral load for HTLV-I infected donors ranged from 0.015 to 12.819 copy/cell in WBC with the mean of 3.116 copy/cell.

Investigation epidemiology and sub-clinical infection of hepatitis E in voluntary blood donors in south Zhejiang / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the southern region of Zhejiang hepatitis E virus (HEV) infection.</p><p><b>METHODS</b>A cluster sampling strategy was used to sample all blood donors from February to October in 2008 in Wenzhou blood center. Their blood was tested for IgG and IgM antibody against HEV. Reverse transcriptase-polymerase chain reaction(RT-PCR) and sequencing were applied to detect its genotype and sequence homology in HEV IgM-positive specimen.</p><p><b>RESULTS</b>The prevalence of anti-HEV IgG in 3044 cases of blood donors was 33.28%. IgG increased with age. There are certain increase in positive rates between the 20-year-old group and over 40 years of age group from 21.16% to 50.36%. The positive rate of IgM was 0.92%. The ratio of infection among different age group was the highest in the age range from 31 to 40 years and up to 1.90%. IgG and IgM through their negative and positive analysis of samples found in their group with donors age, sex and blood type does not significantly related to each other. Nucleic acids were found in three cases through PCR amplification in all 28 cases of HEV IgM positive samples. The total positive rate was one-thousandth, of which two cases for gene 4, 1 cases of infection for gene 1.</p><p><b>CONCLUSION</b>The results indicate that there was a certain percentage of HEV virus in voluntary blood donors in south Zhejiang.</p>

The preliminary analysis of the recognition epitopes of anti-HEV monoclonal antibodies on HEV ORF2 / 病毒学报

Western blot, capture-PCR, blocking ELISA and synthetic polypeptides were used to systematically study the recognition epitopes on HEV ORF2 of 23 anti-HEV monoclonal antibodies(McAbs) which were previously generated in our laboratory directed against HEV ORF2. Results showed that seven McAbs recognized linear epitopes that located at aa408-458 of HEV ORF2 and 16 conformation-dependent McAbs, most of which recognized the surface epitopes of native HEV, located at aa459-606 of HEV ORF2. The systematical study of the recognition epitopes of anti-HEV McAbs on HEV ORF2 provides important information for the investigation of virus receptor and HEV infection mechanism, as well as its vaccine and diagnostics development.

Evaluation of two anti-hepatitis E virus IgM kits / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To evaluate two commercial anti-hepatitis E virus (HEV) IgM kits used for differential diagnosis of acute enteric viral hepatitis.</p><p><b>METHODS</b>The kit for IgM capture assay, was produced with a recombinant HEV structural protein protecting primates against experimental infection by different HEV genotypes, while the other kit for indirect ELISA was produced with recombinant structural proteins from different HEV genotypes. The serum specimens were taken from 241 cases with a confirmed or presumptive diagnosis of hepatitis A and 74 cases with a confirmed or presumptive diagnosis of hepatitis E.</p><p><b>RESULTS</b>The sensitivity and specificity of the IgM capture assay kit were 97% and 100%, respectively, and the corresponding values for the other kit were 70% and 78%, respectively.</p><p><b>CONCLUSION</b>The IgM capture assay kit has higher sensitivity and specificity in diagnosing acute enteric viral hepatitis E.</p>

Hepatitis E virus infection in population of non-remunerate blood donors in Shaoxing / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the incidence of HEV infection in population of non-remunerate blood donors in Shaoxing.</p><p><b>METHODS</b>Blood specimens from 3701 non-remunerate blood donors were collected, ELISA were used to study anti-HEV IgG and IgM antibodies, RT-PCR were further used to study HEV RNA in samples from donors whose anti-HEV IgM was positive.</p><p><b>RESULTS</b>Anti-HEV IgG positive rate was 29.19% (1107/3701), anti-HEV IgM positive rate was 1.35% (50/3701) among non-remunerate blood donors in Shaoxin. Six cases were positive for HEV RNA. The positive rate was 0.16% (6/3701), and all the 6 cases belonged to HEV genotype 1. Different seasons showed no interference on the positive rate of IgG and IgM.</p><p><b>CONCLUSION</b>The detecting and studying of HEV infection among donors was important to ensure the safety of blood products and blood transfusion.</p>

Establishment of a new combined enzyme immunoassay for detection of HBV preS1 and core antigens and the consistency with HBV DNA test / 病毒学报

In this study, a new combined enzyme immunoassay(NRAg ELISA) for detection of HBV PreS1 and core antigens which was highly consistent with serum HBV DNA test was established. The serial serum dilution test indicated that the average sensitivity of the assay was 10(3.2) genome copies/mL (95% CI: 10(2.2-4.2) genome copies/mL), which was notably higher than the test performed on Pre S1 or core antigen alone. The test with sera from 994 blood donors whose HBsAg were negative demonstrated that the specificity of this assay was 99.7% (95% CI: 99.1%-99.9%). 271 serum samples from chronic hepatitis patients were also examined and the result showed that the total consistent rate between NRAg ELISA and HBV DNA was 96.3% (95% CI: 93.3%-98.2%). The NRAg ELISA S/CO(signal/cutoff) was closely correlated with HBV genome copies (R = 0.9158, n=231). Furthermore,by using this assay,we found a patient whose HBsAg was negative but HBV DNA was positive. Sequencing result showed that HBV genome from this patient had a point mutation in the "a"epitope of S gene. Our results indicate that HBV NRAg ELISA has a high relativity with HBV DNA test, and can effectively detect the mutation of HBsAg,it is expected to be a potent tool for screening HBsAg mutant and is a convenient method for substituting HBV DNA test.

The molecular differences between genotype 1 and genotype 4 of HEV in their neutralization region / 病毒学报

HEV is classified into H (human) group and Z (zoonosis) group according to its compatible host. H group contains genotype 1 and genotype 2 HEV isolates which infect human only; Z group contains genotype 3 and genotype 4 HEV isolates which infect both human and animals. After analysis of amino acid sequences between ORF2 aa368 and aa606, four group-conserved sites that were all located in the neutralization region of ORF2 were identified. They are aa483, aa492, aa497 and aa599. Mutation analysis and capture PCR were then performed on these sites with a group of monoclonal antibodies. Results showed that the difference of the aa497 between H and Z groups was responsible for the maintenance of their group-specific immunodominant epitopes, probably through confirmation-dependent epitope changes. Thus, aa497 and its related change on the surface structure of HEV may play important roles in host selection by H and Z groups of HEV.

Significance of serological markers and virological marker for hepatitis E in rhesus monkey model / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To evaluate the serological markers and biological marker in the diagnosis of hepatitis E infection in a rhesus monkey model.</p><p><b>METHODS</b>86 rhesus monkeys had been infected with different doses of HEV. Hence, they were taken sequential blood samples at intervals up to 86 weeks for 4 hepatitis E virus (HEV) specific antibody assays (E2-IgM, E2-IgG, GL-IgG, and YES-IgG), and nucleic acid assay.</p><p><b>RESULTS</b>All the animals produced E2-IgG and all but one also produced E2-IgM and excreted the virus in stool, whereas positive rate of GL-IgG and YES IgG were low and correlated with virus level. Hepatitis occurred over a period of 4 weeks (between 3 an 7 weeks) after infection. Virological marker occurred mainly during incubation period and declined rapidly after onset of hepatitis. Seroconversion of E2-IgM occurred before onset of hepatitis in 70% monkeys and declined rapidly up to 50% of peak value after 4 weeks. E2-IgM seroconversion was closely paralleled by E2-IgG; however, E2-IgG persisted in all animals for the entire duration of experiment of up to 86 weeks. Production of GL-IgG and YES-IgG was delayed by one week after the E2 antibodies, these antibodies showed a transient occurrence and seroprevalence declined to 50% of the peak value over a period of 12 weeks.</p><p><b>CONCLUSION</b>E2-IgM might be used as a suitable acute hepatitis E marker, and E2-IgG as a suitable epidemiological marker. The seroconversion or titer elevation of GL-IgG and YES-IgG antibodies probably used to confirm the infection. The viral markers are optional for early diagnosis.</p>

Detection of hepatitis E virus on a blood donor and its infectivity to rhesus monkey / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To understand the infectivity and pathogenicity of the plasma of hepatitis E virus (HEV) viremia to primate animals.</p><p><b>METHODS</b>RNA fragment of HEV genotype IV was detected on one healthy donor who was positive for anti-HEV IgM and negative for anti-HEV IgG. Then 10 ml plasma from above donor was transfused to rhesus monkey to observe its infectivity and pathogenicity.</p><p><b>RESULTS</b>Acute hepatitis E was developed in rhesus monkey who accept HEV RNA positive plasma. It was confirmed by virological, immunological, biochemical and histopathological data.</p><p><b>CONCLUSION</b>Acute hepatitis E can be induced by plasma transfusion of HEV viremia, which indicate the possibility of transfusion transmitted hepatitis E</p>

Evaluation of the reliability of three different hepatitis E diagnosis reagents on the clinical acute hepatitis E / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To evaluate the reliability of different hepatitis E diagnosis reagent tests on the acute hepatitis E.</p><p><b>METHODS</b>Three acute hepatitis E diagnosis tests, E2-IgM (Wantai, China), GL-IgM and GL-IgG (Genelabs, Singapore) were compared for their reliability in a sera panel composed by 273 healthy individuals and 525 hepatitis.</p><p><b>RESULTS</b>The specificity of E2-IgM on the diagnosis of acute hepatitis E was 100.0%, it was significantly higher than GL-IgM (96.7%) and GL-IgG (85.4%). The sensitivity of E2-IgM and GL-IgG were 97.9% and 93.8% respectively, both significantly higher than GL-IgM (72.9%). Among 65 acute hepatitis cases being positive on GL-IgM test but negative on E2-IgM, 58 (89.2%) cases were found to be positive with anti-hepatitis A virus IgM, it indicated that the GL-IgM test might be interfered by other IgM antibodies on serum.</p><p><b>CONCLUSION</b>E2-IgM is a good test for the diagnosis of acute hepatitis E.</p>

Serological characteristics of a hepatitis E outbreak / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To look into the serological characteristics of a hepatitis E outbreak.</p><p><b>METHODS</b>Sera from the first five patients with acute icteric hepatitis who developed the disease successively within ten days and the 1,675 employees routinely having their lunch in a dining hall of a department (outbreak population) were examined for anti.HEV IgM and IgG at 26th days after the outbreak, and the 883 employees of a neighboring department not having their lunch in the hall were selected as control (control population).</p><p><b>RESULTS</b>The five patients were all positive for anti-HEV IgM and IgG. The positive rates of anti-HEV IgM and IgG in outbreak population were 8.7% and 38.4% respectively, both significantly higher than those in control population which were only 0.1% and 28.6%. The numbers with abnormal ALT in the 145 individuals with anti-HEV IgM(+) of outbreak population were significantly higher than those in the IgM(-) individuals of the same group as well as in control, while the abnormal ALT ratio in the IgM(-) individuals of the outbreak was not higher than that in control. The results from the four patients' serial sera showed that the anti-HEV IgM titers declined gradually and were undetectable at about 4th month after infection, and the IgG titers increased to peak in about 2-3 months after infection, then declined very slowly. The mean IgG titer of the anti-HEV IgM(+) individuals was significantly higher than that of the IgM(-) but IgG(+) individuals in outbreak population, and the latter was significantly higher than the IgG(+) individuals in control, which suggested that the post-infection individuals' immunities to HEV were boosted during the outbreak. There was no difference between sex or age groups for the anti-HEV IgM(+) ratio, but the abnormal ALT was much more frequent in the anti-HEV IgM(+) male than in the female, and no difference was observed between age groups.</p><p><b>CONCLUSION</b>The pathogen of the outbreak of acute icteric hepatitis was hepatitis E virus and associated with food intake. Anti-HEV IgM and IgG were used not only for diagnosis of hepatitis E but also for surveilance in mass population. The attack risk was not associated with age or sex, but the abnormal ALT was much more frequent fresh infectors in male.</p>

The study of aggregate of the ORF2 peptide of hepatitis E virus expressed in Escherichia coli / 生物工程学报

A fragment of hepatitis E virus open reading frame-2(ORF2), located from amino acid residues 394 to 604, was expressed in E. coli. The recombinant protein NE2 was found to form homodimer mostly in SDS-PAGE, which can be dissociated to monomers when treated with urea, and it was recognized more strongly in its dimeric form than the monomer by HEV reactive human serum in Western blotting. Besides, many aggregated form of NE2 from dimer to at least hexamer can be seen in MALDI-TOF-MS. And when the hydrated dynamic semidiameter of NE2 moleculars in PBS was measured as about 4 nm by Dynamic Light Scattering (DLS), being equal to tetramer, but with high polydispersity, which suggested that the NE2 moleculars were existed in PBS in many different sizes. These results suggested that the recombinant NE2 can aggregate into several oligomer forms, the association in the dimer is most strong, and dimers can assemble further to form some super-structure.