DNA-Based Vaccination Primes Tumor-Rejecting T-Cell Responses

DNA-based vaccination efficiently primes MHC-restricted T-cell responses. This technique specifically stimulates MHC-II-restricted CD4(+) T-cell responses and MHC-I-restricted CD8(+) T-cell responses against "strong" (immunodominant) or "weak" (subdominant or cryptic) epitopes of intracellular, secreted or membrane-associated protein antigens. In many experimental systems, T-cell-mediated effector functions have the potential to control tumor growth. In particular MHC-I-restricted cytotoxic T lymphocytes (CTL) can reject tumors. This has been shown using either defined tumor-associated antigens (TAA), or viral antigens containing well-defined, MHC-binding and CTL-stimulating epitopes that are expressed by transfected tumor cells.