Abstract
Human T cells that recognize a major epitope of the hepatitis B surface antigen were studied for their ability to react with antigen when presented by mouse fibroblasts that express class II products of the human major histocompatibility gene complex after gene transfection. L cells expressing HLA-DPw4, but not those expressing HLA-DR4 or HLA-DR7, induced strong proliferative responses of antigen-specific T cells to either hepatitis B surface antigen or the synthetic peptide S1d, which bears the immunodominant T-cell epitope. These results identified a genetic restriction element of human helper T-lymphocyte responses to a major antigenic determinant of hepatitis B virus and might be important in the design of subunit vaccines to this pathogen. Peptides that induce T-cell responses that are restricted by a frequently encountered major histocompatibility complex molecule in the general population such as DPw4 would be ideal candidates as subunit vaccines.