Adoptive immunotherapy of cancer requires the generation of large numbers of tumor antigen-reactive T cells for transfer into cancer patients. Genes encoding tumor antigen-specific T-cell receptors can be introduced into primary human T cells by retroviral mediated gene transfer as a potential method of providing any patient with a source of autologous tumor-reactive T cells. A T-cell receptor-specific for a class I MHC (HLA-A2)-restricted epitope of the melanoma antigen tyrosinase was isolated from a CD4(+) tumor-infiltrating lymphocyte (TIL 1383I) and introduced into normal human peripheral blood lymphocytes by retroviral transduction. T-cell receptor-transduced T cells secreted various cytokines when cocultured with tyrosinase peptide-loaded antigen-presenting cells as well as melanoma cells in an HLA-A2-restricted manner, and could also lyse target cells. Furthermore, T-cell clones isolated from these cultures showed both CD8(+) and CD4(+) transduced T cells could recognize HLA-A2(+) melanoma cells, giving us the possibility of engineering class I MHC-restricted effector and T helper cells against melanoma. The ability to confer class I MHC-restricted tumor cell recognition to CD4(+) T cells makes the TIL 1383I TCR an attractive candidate for T-cell receptor gene transfer-based immunotherapy.