Hepatitis E ; etiology ; prevention & control ; Hepatitis E virus ; immunology ; Humans ; Viral Hepatitis Vaccines ; immunology

China ; epidemiology ; Hepatitis E ; epidemiology ; Hepatitis E virus ; genetics ; immunology ; Humans ; Immunoglobulin E

Animals ; Hepatitis E ; prevention & control ; Hepatitis E virus ; immunology ; Humans ; Viral Hepatitis Vaccines

OBJECTIVETo observe anti-HEV IgG response to vaccination of recombinant antigen fragments and evaluate its protection from Hepatitis E Virus infection in rhesus monkeys (Macaca mulatta).

METHODSTwelve monkeys were divided into three groups and immunized respectively with three different recombinant antigens: namely Ag1 (carboxyl terminal 431 amino acids of ORF2), Ag2 (128aa fragment at the carboxyl terminal of ORF2), and Ag3 (full length ORF3 ligated with two ORF2 fragments encoded by 6743-7126nt and 6287-6404nt). The monkeys were challenged intravenously with fecal suspension from experimentally infected rhesus monkeys, and the other three monkeys served as the placebo group for challenge with HEV. The dynamic changes of the levels of ALT and anti-HEV IgG were examined. Pathological changes of liver tissue were observed by light microscope. Excretion of virus was detected by RT-nPCR.

RESULTSHepatic histopathology of two monkeys in the placebo group was consistent with acute viral hepatitis, and ALT was elevated 3-4 weeks after inoculated with virus, up to 10-20 times higher than normal level. The liver tissue of monkeys immunized with antigen kept normal, ALT in several monkeys elevated mildly, and anti-HEV IgG conversation occurred at 1-2 weeks after vaccination, with the titer reaching 1:12,800. The virus RNA could be detected by RT-nPCR from days 7 to 50 in monkeys of control group, and from days 7 to 21 in vaccinated monkeys after challenged with virus.

CONCLUSIONSThe recombinant antigens could induce the production of anti-HEV IgG, which protected rhesus monkeys from acute Hepatitis symptoms related to HEV infection.

Animals ; Antigens, Viral ; immunology ; Hepatitis E ; prevention & control ; Hepatitis E virus ; immunology ; Immunoglobulin G ; immunology ; Macaca mulatta ; RNA, Viral ; blood ; Recombinant Proteins ; immunology ; Vaccination ; Viral Hepatitis Vaccines ; immunology

BACKGROUNDTo observe the protective effect of hepatitis E virus (HEV) ORF2 recombinant protein expressed in prokaryote cell cynomolgus macaques (cynos) against challenging with wild-type HEV.

METHODSCynos were immunized with HEV ORF2 recombinant protein and then challenged with wild-type HEV, the unimmunized cynos were used as control. Blood samples were collected and tested to see if there were dynamic changes of ALT and antibody to HEV before and after challenge with wild-type HEV.

RESULTSAll the five unimmunized cynos re-presented hepatitis 3 weeks after challenging with wild-type HEV. However, all the five immunized cynos showed no hepatitis and pathological changes.

CONCLUSIONSCynos can be efficiently protected by immunization with HEV ORF2 recombinant protein against wild-type HEV. This protein can be a promising candidate for HEV vaccine.

Animals ; Female ; Hepatitis Antibodies ; blood ; Hepatitis E ; immunology ; prevention & control ; Hepatitis E virus ; immunology ; Macaca mulatta ; Male ; Recombinant Proteins ; immunology ; Viral Proteins ; immunology

OBJECTIVETo predict and identify B-cell linear epitopes of hepatitis B e antigen (HBeAg).

METHODSThe B-cell linear epitopes of HBeAg were predicted using the software provided by NCBI Database and Immune Epitope Database (IEDB) and synthesized by a solid-phase method followed by conjugation with keyhole limpet hemocyanin (KLH). The KLH conjugates were used for immunization of New Zealand white rabbits, and the immune response of the rabbits was monitored by direct ELISA using a bovine serum albumin conjugate of the predicted epitopes. RESULTS Four new B-cell linear epitopes of HBeAg were identified, namely (1)MDIDPYKEFG(10), (37)LYREALESPEHCSP(50), (74)SNLEDPAS(81) and (127)RTPPAYRPPNAPIL(140). The rabbits immunized with the KLH conjugate showed an antibody titer over 1:512 000. The antisera of B-cell linear epitopes collected could specifically react with HBeAg as shown by ELISA.

CONCLUSIONFour B-cell linear epitopes of HBeAg have been confirmed using bioinformatics methods, which provides new evidence for further functional studies of HBeAg in hepatitis B.

Animals ; Computational Biology ; Epitopes, B-Lymphocyte ; immunology ; Hepatitis B e Antigens ; immunology ; Hepatitis B virus ; immunology ; Rabbits

Hepatitis B ; immunology ; virology ; Hepatitis B Antibodies ; blood ; Hepatitis B e Antigens ; blood ; Hepatitis B virus ; immunology ; physiology ; Humans ; Immunologic Tests ; methods ; Virus Replication

China ; epidemiology ; Female ; Hepatitis E ; blood ; epidemiology ; Hepatitis E virus ; immunology ; Humans ; Immunoglobulin M ; blood ; Male ; Middle Aged

OBJECTIVETo evaluate the serological markers and biological marker in the diagnosis of hepatitis E infection in a rhesus monkey model.

METHODS86 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.

RESULTSAll 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.

CONCLUSIONE2-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.

Alanine Transaminase ; blood ; Animals ; Biomarkers ; Genotype ; Hepatitis Antibodies ; blood ; Hepatitis E ; diagnosis ; Hepatitis E virus ; classification ; genetics ; immunology ; Immunoglobulin E ; blood ; Immunoglobulin M ; blood ; Macaca mulatta

OBJECTIVETo understand the prevalence of sub-clinical infection of hepatitis E virus (HEV) among blood donors.

METHODSA cluster sampling strategy was used to sample all blood donors from July to August in 2002 in Beijing. Their blood was tested for IgM and IgG antibody against HEV.

RESULTSThe prevalence of anti-HEV IgM among blood donors in Beijing was 1.74%. The rate of abnormal alanine aminotransferase (ALT) in anti-HEV IgM positive donors is significantly higher than anti-HEV IgM negative donors. Among all ALT abnormal donors, 2.68% can be associated with HEV sub-clinical infection. The percentage is similar with HBV but higher than HCV.

CONCLUSIONThere are sub-clinical infection of HEV among blood donors, which is one of the cause of abnormal ALT in the donors.

Adult ; Alanine Transaminase ; blood ; Blood Donors ; Female ; Hepacivirus ; immunology ; Hepatitis Antibodies ; blood ; Hepatitis E ; epidemiology ; Hepatitis E virus ; immunology ; Humans ; Immunoglobulin M ; blood ; Male