Hepatitis B ; immunology ; prevention & control ; Hepatitis B Vaccines ; immunology

Hepatitis C, Chronic ; immunology ; Humans

Hepatitis B virus (HBV) currently infects more than 400 million people worldwide and they are at risk of developing chronic liver disease, cirrhosis and hepatocellular carcinoma. The immune response to HBV- encoded antigens is responsible both for viral clearance and for disease pathogenesis during HBV infection. While the humoral antibody response to viral envelope antigens contributes to the clearance of circulating virus particles, the cellular immune responses to the envelope, nucleocapsid, and polymerase antigens were known to eliminate virus in infected hepatocytes through cytolytic as well as noncytolytic mechanisms. Liver injury could be initiated by an immune response against HBV, but mainly resulted from HBV non-specific lymphocytes and macrophages. There are growing evidences that T helper 1 memory T cells play a predominant role in suppressing viral replication mainly by IFN-gamma through noncytolytic antiviral mechanism. Elucidation of the immunological and virological basis for HBV infection may yield effective immunotherapeutic and antiviral strategies to terminate chronic HBV infection.
Humans ; Hepatitis B virus/*immunology ; Hepatitis B Antigens/immunology ; Hepatitis B/*immunology

Hepatitis C virus (HCV) infection is a worldwide problem in terms of public health. It causes chronic hepatitis C in 60-80% of patients after acute hepatitis C. Chronic hepatitis C can progress to liver cirrhosis and hepatocellular carcinoma. In the present time, combination therapy of pegylated interferon-alpha and ribavirin is the standard therapy for hepatitis C, but it results in sustained virologic response only in 45-80% of treated patients. In addition, there is no available effective vaccine for HCV. To develop effective immunotherapy or preventive vaccine, understanding of the immune response against HCV is prerequisite. Among several components of immune system, T cells play a key role in the clearance of HCV and immunopathology during hepatitis C. In the study of HCV infection, however, the most important limiting factor is the absence of small animal model as only humans and chimpanzees can be infected by HCV. In this review, T cell response against HCV, which has been known from the studies of the HCV-infected patients and chimpanzees, will be discussed in several circumstances, including acute hepatitis C, chronic hepatitis C and recovered status from hepatitis C.
T-Lymphocytes/*immunology ; Humans ; Hepatitis C, Chronic/immunology ; Hepatitis C/*immunology ; Hepacivirus/immunology

Epitopes ; immunology ; Hepacivirus ; immunology ; Hepatitis C ; immunology ; Humans

OBJECTIVETo analyze the characteristic of T cell response to specific antigen proteins in patients with hepatitis B virus infection.

METHODS76 cases were recruited, including four groups, acute hepatitis B (AHB), active phase of chronic hepatitis B (CHB), inactive HBV carriers (AsC) and past HBV infection. T cell responses stimulated by 3 antigen specific proteins of HBV were detected using enzyme linked immunospot (ELISPOT) assay.

RESULTS(1) There were no significant difference in frequencies to HBsAg, HBcAg and HBeAg in AHB and CHB. The frequencies to HBsAg and HBcAg in AsC were lower than that to HBeAg, and the frequencies to HBsAg in group of past HBV infection were significantly lower than that to HBcAg and HBeAg. (2) The frequencies to HBsAg in AHB and CHB both were higher than in group of past HBV infection. The frequencies to HBcAg of AHB, CHB and AsC were higher than that of group of past HBV infection. (3) There were no significant difference in magnitude to HBsAg, HBcAg and HBeAg in AHB and AsC. In CHB, the magnitude to HBsAg was lower than that to HBcAg. The magnitude of in group of past HBV infection were HBcAg > HBeAg > HBsAg. (4) In four groups, the sequence of the magnitude to HBsAg from high to low was AHB, CHB, group of past HBV infection and AsC. The magnitude to HBcAg in of AsC was lower than other three groups. As to the magnitude to HBeAg, the difference was no significant between any two groups except between AHB and CHB.

CONCLUSIONSThe T cell responses in group of AsC to HBeAg were the highest, while the T cell responses to HBcAg were the highest in group of other groups.

Hepatitis B ; immunology ; virology ; Hepatitis B Antibodies ; immunology ; Hepatitis B Core Antigens ; immunology ; Hepatitis B Surface Antigens ; immunology ; Hepatitis B e Antigens ; immunology ; Hepatitis B virus ; immunology ; isolation & purification ; Humans ; T-Lymphocytes ; immunology

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

In this study, three expression vectors encoding unmodified glycoproteins E1 and E2 from H77 (1a), Hebei (1b) and JFH1 (2a) strains were constructed to form pVRC-H77-E1E2, pVRC-HeBei-E1E2 and pVRC-JFH1-E1E2 expressing constructs. The protein expression was confirmed by immunofluorescene assay(IFA) and Western blot. The Lentiviral vector has the ability to package the cellular membrane into pseudo-particles. The plasmid expressing HCV E1-E2 glycoproteins in native form was co-transfected into 293FT cells with a lentiviral packaging plasmid (pHR'CMV delta R8.2)and a self-inactivated (SIN) transfer plasmid (pCS-CG) containing a reporter EGFP gene to produce infectious HCV pseudo-particles(pp). Flow cytometry assays showed that the HCVpp could infect Huh7 and Huh7-CD81, and the infectivity in Huh7-CD81 was about 2-3 times higher than that in Huh7 cells. Meanwhile, HCVpp could neither infect non-liver cells, for example, the 293 cells, nor HepG2 cell . Titration of HCVpp by p24 ELISA assay or infection assay showed that this HCVpp may contain 5-25 ng/mL p24 or 10(4)-10(5) TU (transducing unit)/ ml. An in vitro HCV neutralizing assays based on HCVpp (1a, 1b, 2a) were then established using AP33, a monoclone antibody with cross-neutralizing ability to different HCV strains. The neutralizing ability of the antibodies from HCV infected patients was further studied with this HCVpp system. In summary, three kinds of HCVpp (1a, 1b, 2a subtype) were successfully developed; In vitro HCV neutralizing assays based on HCVpp and SIN lentiviral system were established. This system paves a way for characterization of early steps of HCV infection (host tropisms, receptor binding, membrane fusion, et al. ) or screening anti-HCV drugs (such as inhibitor to virus entry). This system can be further applied to assess the human immune responses in HCV patients or evaluate HCV vaccine candidates.
Hepacivirus ; immunology ; Hepatitis C Antibodies ; immunology ; Hepatitis C, Chronic ; immunology ; Humans ; Neutralization Tests ; Viral Envelope Proteins ; immunology ; Virion ; immunology

Hepatitis B ; immunology ; prevention & control ; Hepatitis B Vaccines ; immunology ; Humans ; Immunization Schedule ; Vaccination ; Vaccines, Synthetic ; immunology

Autoantibodies ; immunology ; Female ; Hepatitis, Autoimmune ; immunology ; Hepatitis, Viral, Human ; immunology ; Humans ; Male