Abstract: Provided are a production method for cytotoxic T cells with increased recognition of cancer cells, a cancer treatment drug including said cytotoxic T cells, and a treatment method using said treatment drug.

Abstract: A method for inducing an antigen-specific cytotoxic T lymphocyte (CTL) which recognizes determinants of disease-related antigens, such as from cancer or tumor cells, viral infections, intracellular bacterial infections, or parasitic infections. Lymphocytes are contacted or co-cultured with a cell line which expresses at least one major histocompatibility (MHC) class I molecules and a co-stimulatory molecule, after or while bringing the cell line into contact with a disease antigenic peptide. Alternatively, the lymphocytes may be contacted with a cell line expressing at least one MHC class I molecules and an accessory molecule and presenting an antigen. The CTLs induced by these methods may be used to treat cancer or infectious diseases. Methods for testing the proliferation potential of a lymphocyte sample using cell lines expressing MHC class I molecules and accessory molecules are also disclosed.