Patent ID: 8728811

Claim:
A method for expanding cytotoxic lymphocytes which comprises: culturing precursor cells, capable of differentiating to cytotoxic lymphocytes, wherein the precursor cells are selected from the group consisting of peripheral blood mononuclear cells and blood components containing these cells in the presence of at least one recombinant fibronectin fragment together with interleukin-2 and an anti-CD3 antibody, wherein the recombinant fibronectin fragment is a polypeptide comprising an amino acid sequence selected from the group consisting of SEQ ID NOS: 8 to 19, wherein said culturing is performed for 2-15 days, wherein the expanded cytotoxic lymphocytes maintain cytotoxic activity longer than cytotoxic lymphocytes expanded in the absence of at least one fibronectin fragment, wherein said cytotoxic activity of the expanded cytotoxic lymphyocyte is evaluated as the cytotoxic activity against a target cell labeled with a fluorescent substance by determining fluorescent intensity ascribed to the target cell destroyed by said expanded cytotoxic lymphyocyte, and wherein the expanded cytotoxic lymphocytes express more CD8 than cytotoxic lymphocytes expanded in the absence of at least one fibronectin fragment.