Expansion of NK cells and therapeutic uses thereof
The present invention relates to novel methods for preferentially activating and expanding NK cells. The methods utilize the stimulatory effects of IL-15 and CD137 ligand to preferentially expand and activate NK cells in a mixed cell culture comprising NK cells.
1. A modified cell line comprising cells that lack major histocompatibility complex I molecules wherein said cells are genetically modified to express membrane bound interleukin-15 and a co-stimulatory factor ligand CD137L, where said modified cell line activates natural killer (NK) cells and fails to activate T lymphocytes.
2. The cell line of claim 1 , wherein said cells also lack major histocompatibility complex II molecules.
3. A method of preferentially expanding natural killer (NK) cells in a mixed cell culture comprising NK cells and T lymphocytes which comprises culturing said mixed cell culture with a modified cell line comprising cells that lack major histocompatibility complex I molecules wherein said cells are genetically modified to express membrane bound interleukin-15 and a co-stimulatory factor ligand CD137L, where said modified cell line activates natural killer (NK) cells and fails to activate T lymphocytes.