Immune response of peripheral blood mononuclear cells to antigenic determinants within hepatitis B core antigen in HB virus-infected man

Review of cytokine profiles in patients with hepatitis

The development of T helper 1 versus T helper 2 cells is a major branch point in the immune response and is an important determinant of the body’s response to an infectious pathogen, leading to protection of the host or dissemination of the disease. Resent studies have shown that there exist macrophage activation states in parallel to the T helper cell type 1/2 paradigm, and the T helper 1 development process is governed to a great degree by cytokine IL-12 provided mainly by antigen presenting cells such as macrophages and dendritic cells. A model in patients with hepatitis is proposed that links the pathogen, macrophage activation and T helper cell polarization.

Role of hepatitis B virus in non-B, non-C chronic liver disease: in vitro proliferation and interferon-gamma production of peripheral blood mononuclear cells in response to hepatitis B core antigen and its relation to hepatitis activity

OBJECTIVE

Although hepatitis B virus (HBV) DNA has been detected in the sera of patients with chronic liver disease with neither hepatitis B surface antigen nor antihepatitis C virus antibody (non-B, non-C [NBNC] CLD), whether HBV has some pathogenic role in NBNC CLD has not been made clear.

METHODS

To investigate the significance of HBV DNA in NBNC CLD, we performed in vitro stimulation assays of peripheral blood mononuclear cells (PBMCs) in response to hepatitis B core antigen (HBcAg) in 17 NBNC CLD patients.

RESULTS

HBV DNA with an 8-nucleotide deletion in the core promoter region was detected in 13 (76%) of the 17 patients by nested polymerase chain reaction. Interferon-gamma (IFN-gamma) production and proliferation of PBMCs of HBV DNA-positive patients showed a significant increase in response to HBcAg. The histological activity of hepatitis was also found to be significantly associated with the magnitude of IFN-gamma production and proliferation of PBMCs in response to HBcAg. Although five (38%) of the 13 HBV DNA-positive NBNC CLD patients had anti-HBs and/or anti-HBc, there was no difference in response of PBMCs to HBcAg between the HBV DNA-positive and -negative groups.

CONCLUSION

Our observation suggests that HBV may have a pathogenic role in HBV DNA-positive NBNC CLD, even in those patients without any serological markers of HBV.

Proliferative response of CD4+ T cells and hepatitis B virus clearance in chronic hepatitis with or without hepatitis B e-minus hepatitis B virus mutants

To assess the significance of cell-mediated immunity, T cells were derived from the peripheral blood and liver tissue of hepatitis B virus (HBV)-infected patients and controls. The analysis of the 3H-thymidine-uptake in response to a panel of recombinant HBV antigens revealed that peripheral blood mononuclear cells (PBMC) of the 25 viremic patients with inflammatory active, chronic hepatitis B, 16 with wild-type and nine with HBe-minus HBV mutant infection, showed stronger proliferative responses to HBc and HBe antigens than 16 asymptomatic nonviremic HBsAg carriers with normal aminotransferase levels (HBc: SI 19.3 +/- 3.9 vs. 13.0 +/- 3.2 vs. 8.0 +/- 1.2; P < .01 and HBe: SI 16.6 +/- 4.0 vs. 10.7 +/- 3.5 vs. 6.9 +/- 1.5; P < .05). In 15 patients with acute self-limited hepatitis B, however, significantly stronger HBc antigen-specific T-cell responses were observed during HBV clearance and HBe/anti-HBe seroconversion, whereas in nine completely HBV-immunized patients only minor proliferative responses to HBV antigens were observed. Six HBe/HBcAg- and two HBeAg-specific CD4+ T-cell lines could be expanded from liver tissue and peripheral blood of six viremic patients with chronic hepatitis B. Irrespectively of HBV mutations the HBV-specific activation of the T-cell lines was restricted by the presence of HLA-DR molecules and resulted in the release of Th1-like cytokine patterns. Follow-up of interferon (IFN) recipients showed simultaneous short-term increase of HBc/HBe-specific T-cell reactivities in responder patients during HBV clearance and HBe/anti-HBe seroconversion, whereas in nonresponders high virus load and HBV-specific immune responses were in imbalance.(ABSTRACT TRUNCATED AT 250 WORDS)