CYTOTOXIC T-CELL RESPONSES IN PATIENTS WITH CHRONIC HEPATITIS-B VIRUS-INFECTION UNDERGOING HBE ANTIGEN-ANTIBODY SEROCONVERSION

Cytotoxic T cells have been identified in the peripheral blood of pati ents with acute hepatitis B virus infections for a short period after clinical presentation. However, in patients in whom the virus persists these have been difficult to demonstrate. In the chronic infection du ring HBe antigen clearance, when there has been an exacerbation of the disease, we have been able to demonstrate an MHC class I-restricted c ytolytic response directed against the nucleocapsid antigens. In an HL A-A2 patient this was induced in vitro with the peptide p18-27, previo usly described as an HLA-A2-restricted T cell epitope. In patients of other HLA types, recombinant core antigen was used to induce antigen-s pecific lysis: statistical analysis of the cytolytic responses of chro nically infected patients demonstrated a nucleocapsid antigen-specific lysis in patients who were seroconverting. Removal of CD4(+) cells re duced non-MHC-restricted cytolysis, allowing an MHC class I-restricted cytolytic component to be demonstrated.