Search

Eight donors immune to hepatitis B(HB)after natural infection were studied for their cellmediated immune response to hepatitis B core (HBc) protein in vitro. Significant specific activation was observed in highly purified peripheral blood lymphocytes and T cells from these donors after 5-8 days of incubation with HBc protein. This in vitro response wits modulated by monocytic cells and maximal ³H-thymidine incorporation was elicited with low concentrations of the antigen (0.1-10 ng/ml). The cell-mediated immune reactivity towards HBc-protein was significantly (P<0.005) elevated compared to the envelope material of the virus (HBsAg) when analysed in the same donor population. In contrast, donors with plasma-derived hepatitis B vaccine induced immunity lo HB exhibited only specific lymphocyte activation to HBsAg, These data Indicate that the composition of immune responses conferring protection against HBV after natural infection is far more complex than after immunization with the hepatitis B vaccine. Further characterization of the cell-mediated immune response to HBc protein and its relation to protection against HBV seems warranted when strategies for new HB-vaccines are being designed. [ABSTRACT FROM AUTHOR]

The article focuses on human serum albumin (HSA) and the enigma of chronic hepatitis type B. The interaction between HSA and virus particles permits the entrance of HBV into uninfected hepatocytes. It has been demonstrated that antigen associated with self carriers induces immunological unresponsiveness. The ease of tolerance induction is favoured by intravenous administration of antigen in high concentration in soluble form. Immature B cells in neonates are highly susceptible to tolerance induction. Reactive B-cell clones are deleted or rendered anergic when exposed to antigen in a tolerogenic form.