Identification of an epitope for T-Cells correlated with antibody response to hepatitis B surface antigen in vaccinated humans

Two antigenic T-cell epitopes of HBsAg, designated HBs16-31 and HBs81-99, were identified using synthetic peptides and HBsAg-specific T-cell lines. HBs16-31 was recognized by five HBsAg-specific T-cell lines from vaccinees with both high and low antibody titers, whereas HBs81-99 was recognized by two T-cell lines derived from vaccinees with high antibody titers. The antibody titer against HBsAg was correlated significantly with the proliferation of vaccinee's PBLs in response to HBs81-99 (r = 0.47) but not to HBs16-31, suggesting that HBs81-99 plays a critical role in anti-HBs antibody production in humans vaccinated with HBsAg.