Stem Cell Technology May Restore Cancer-Fighting Power to Immune Cells

Invariant natural killer T (iNKT) cells are toxic immune cells that serve as important regulators of immune responses to fight off cancer cells. The function and quantity of iNKT cells are often suppressed in cancer patients. In an attempt to restore the function of these weakened iNKT cells, researchers from Kyoto University and the National Cancer Center in Japan reprogrammed iNKT cells isolated from patients to create induced pluripotent stem cells (iPSCs), which have the capability to generate any cell in the body. Using an optimized set of molecules called cytokines, they were able to direct these iPSCs to become iNKTs again. The newly differentiated iNKT cells exhibited many of the properties of the original iNKTs, were able to interact with other immune cell types, and showed more potent killing activity against cancer cells in a dish. This novel immunotherapy strategy allows for restoration of function and number (given the ability of iPSCs to reproduce themselves) of a potent immune cell type essential for killing off cancer cells. This research also illustrates how such patient-focused research can lead to development of therapies relevant to human diseases quickly without the need to use animal models.