Identification of HLA-DRB1*1501-restricted T-cell epitopes from prostate-specific antigen.

The development of immunotherapy for prostate cancer based on the induction of autoimmunity to prostate tissue is very attractive because prostate is not a vital organ beyond the reproductive years. CD4 T cells play an important role in the development of antitumor immune responses, yet the identification of naturally processed MHC Class II-restricted epitopes derived from prostate differentiation antigens has not been described. To facilitate the search for prostate-specific antigen (PSA)-derived MHC class II-restricted peptides, we immunized mice transgenic for HLA-DRB1*1501 with human PSA and showed a robust dose-dependent immune response to the antigen.