Methods for retrovirus-mediated gene transfer to tumor cells

The past several years have seen a renewed interest in active immunotherapy approaches for the treatment of human tumors because of the exciting findings learned from preclinical studies employing genetically altered tumor vaccines. Many clinical protocols are currently being conducted using several different genetic approaches for augmenting antitumor immune responses. These include: 1. Ex vivo gene transfer of cytokine genes into tumor cells. 2. Ex vivo gene transfer of suicide genes into tumor cells with subsequent activation of the suicide mechanism in vivo 3. Ex vivo cytohne gene transfer to cultured tumor-intiltrating lymphocytes (TIL) to generate more potent T-cells for adoptive transfer 4. In viva gene transfer of major histocompatibility complex (MHC) class I molecules by direct injection of the gene into an accessible tumor mass.