FUNCTIONAL IMPLICATIONS OF HEPATITIS-B SURFACE-ANTIGEN (HBSAG) IN THET-CELLS OF CHRONIC HBV CARRIERS

This study was undertaken to investigate the role of T-lymphocyte-deri ved soluble factors in the maintenance of the hepatitis B virus (HBV) chronic carrier state. Cell-free supernatants from the peripheral bloo d T lymphocytes of chronic HBV carriers were produced by incubating th em for 48 h in tissue culture medium. These supernatants were added to in vitro hepatitis B s antibody (HBsAb)-producing cultures of periphe ral blood mononuclear cells from hepatitis B surface antigen (HBsAg) v accinees stimulated with HBsAg or pokeweed mitogen. T-cell supernatant s from chronic carriers suppressed in vitro HBsAb antibody synthesis, whereas those from control subjects did not. This suppression was anti gen specific as the supernatants did not suppress synthesis of total I gG or IgM. HBV viral sequences were demonstrable, by Southern and dot- blot hybridization, in the T cells secreting this factor, We also demo nstrated the presence of HBsAg in T-cell supernatants derived from the se cells. These results show that HBsAg of T-cell origin may have a ro le in suppressing HBsAb production. Our observations point to the role of HBsAg-specific cellular and humoral responses in favouring persist ence of the chronic HBV carrier state.