Immunization against hepatitis B through adoptive transfer of immunity.

Clearance of hepatitis B virus (HBV) infection requires an effective T-cell-dependent humoral response that is often defective in HBV carriers and in immunosuppressed patients. We have shown in mice and humans that bone marrow (BM)-derived memory cells, capable of producing antibodies to the HBV envelope and nucleocapsid antigens, are transferable from BM donors (BMD) to their recipients. BMD BALB/c mice were immunized with recombinant HBV surface antigen (HBsAg), and BM from anti-HBs-positive donors was transplanted to irradiated recipient mice, who seroconverted to anti-HBs within 30 days of bone marrow transplantation (BMT), and responded to booster vaccination. In a similar manner, 19/26 human BM recipients, who received their HLA-matched BM from BMDs immunized once with HBsAg, seroconverted within several weeks after BMT. Antibodies to HBsAg were also observed in 3 recipients of peripheral blood lymphocytes (PBL) obtained from HLA-matched immunized human donors. Finally, clearance of HBsAg and HBV DNA was observed in an HBsAg carrier with leukemia who received BMT from his HLA-matched anti-HBc+/anti-HBs+ brother. These results indicate that adoptive transfer of immunity to HBV may be achieved through immunization of BM or PBL donors against HBV.