Identification of the epitopes on HCV core protein recognized by HLA-A2 restricted cytotoxic T lymphocytes

AIM: To identify hepatitis C virus(HCV) core protein epitopes recognized by HLA-A2 restricted cytotoxic T lymphocyte (CTL). METHODS: Utilizing the method of computer prediction followed by a 4h(51)Cr release assay confirmation. RESULTS: The results showed that peripheral blood mononuclear cells (PBMC) obtained from two HLA-A2 positive donors who were infected with HCV could lyse autologous target cells labeled with peptide "ALAHGVRAL (core 150-158)". The rates of specific lysis of the cells from the two donors were 37.5% and 15.8%, respectively. Blocking of the CTL response with anti-CD4 mAb caused no significant decrease of the specific lysis. But blocking of CTL response with anti-CD8 mAb could abolish the lysis. CONCLUSION: The peptide (core 150-158) is the candidate epitope recognized by HLAA2 restricted CTL.

Humoral and cellular immunogenecity of DNA vaccine based on hepatitis B core gene in rhesus monkeys

INTRODUCTIONHepatitis B virus (HBV) is the most commonetiologic agent for infectious liver diseases. It isestimated that there are more than 250 millionchronic HBV carriersin the world today and thereis a significant association among persistentinfection, liver cirrhosis and hepatocellularcarcinoma[1-3].

A comparative study on serologic profiles of virus hepatitis B

INTRODUCTIONHepatitis B viral infection, one of the most-prevalent liver disorders in China and Korea, is aserious infectious disease as it has the potential ofprogressing into liver cirrhosis and primary hepaticcarcinoma. China and Korea both belong to high-risk endemic regions of viral hepatitis[1]. TheHBsAg positive rates in China ranged from 6.9% -17.9% by age, race and test methods[2-5].

Establishment of transgenic mouse harboring hepatitis B virus (adr subtype) genomes

INTRODUCTIONHepatitis B virus (HBV) belongs to the group ofhepatovirus, a major pathogen of human acute andchronic hepatitis B[1 4], which has a very closeassociation with human hepatocellular carcinoma(HCC)[5-8], For example, a statistical data from ahospital in Shanghai showed that 80% of HCCpatients were positive for HBsAg ( personalcommunication).

Immunogenicity of HGV NS5 protein expressed from Sf9 insect cells

INTRODUCTIONAlthough reliable assays for the detection ofhepatitis C virus and E virus became available, still10% 20% hepatitis are not caused byhepatitis A-E virus[1-3]. In 1996, two research groups isolatedthis agent independently and almost simultaneouslyand named hepatitis G virus and GB virus C,respectively[4-7].

Diagnostic value of human cytomegalovirus late mRNA detection in active intrauterine infection

OBJECTIVE: To study the diagnostic value of human cytomegalovirus (HCMV) late mRNA detection in active intrauterine infection. METHODS: The HCMV late mRNA in peripheral blood of 42 HCMV IgM positive pregnant women and their fetal attachments (such as chorionic villi, amniotic fluid, umbilical blood and placenta) were detected by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Late mRNA was detected in 23 of 42 HCMV IgM positive cases, a rate of 54.3%. Fetal appendages in 13 cases of late mRNA positive mothers were also tested, of which 7 were positive, with a vertical transmission rate of 53.8%. In 12 late mRNA negative mothers, only 1 case of fetal appendages tested was positive, with a vertical transmission rate of 8.3%. There was significant difference between the transmission rates of these two groups. CONCLUSIONS: Positive results of HCMV IgM cannot accurately reflect the activity of HCMV at the time of testing. However, the activity of HCMV is closely related to the mother-fetus vertical transmission rate. As an indicator of active HCMV infection, late mRNA can not only reflect the mother-fetus transmission rate during active HCMV infection, but also provide some information about HCMV activity in fetal tissue.

Humoral immune responses in rabbits induced by an experimental inactivated severe acute respiratory syndrome coronavirus vaccine prepared from F69 strain

BACKGROUND: The etiologic agent of severe acute respiratory syndrome (SARS) has been confirmed to be a novel coronavirus (CoV), namely SARS-CoV. Developing safe and effective SARS-CoV vaccines is essential for us to prevent the possible reemergence of its epidemic. Previous experiences indicate that inactivated vaccine is conventional and more hopeful to be successfully developed. Immunogenicity evaluation of an experimental inactivated SARS-CoV vaccine in rabbits was conducted and reported in this paper. METHODS: The large-scale cultured SARS-CoV F69 strain was inactivated with 0.4% formaldehyde and purified, then used as the immunogen combined with Freund's adjuvant. Eight adult New Zealand rabbits were immunized four times with this experimental inactivated vaccine. Twelve sets of rabbit serum were sampled from the third day to the seventy-fourth day after the first vaccination. The titers of specific anti-SARS-CoV IgG antibody were determined by indirect enzyme-linked immunosorbent assay, and the neutralizing antibody titers were detected with micro-cytopathic effect neutralization test. RESULTS: Rapid and potent humoral immune responses were induced by the inactivated SARS-CoV vaccine in all the eight test rabbits. Titers of both specific IgG antibody and neutralizing antibody peaked at about six weeks after first vaccination, with the maximum value of 1:81 920 and 1:20 480, respectively. After that, serum antibody levels remained at a plateau or had a slight decrease, though two boosters were given in the succedent 4 to 5 weeks. Cross neutralization response existed between SARS-CoV F69 strain and Z2-Y3 strain. CONCLUSIONS: The inactivated SARS-CoV vaccine made from F69 strain owns strong immunogenicity, and the cross neutralization response between the two different SARS-CoV strains gives a hint of the similar neutralizing epitopes, which provide stable bases for the development of inactivated SARS-CoV vaccines.