NK Cell and NKT Cell Immunotherapy

NK cells are a vital component of our innate immune system and serve a variety of biologic functions, including the eradication of tumor. Their importance in preventing leukemic relapse after stem cell transplantation is well documented. The cytotoxic activity of NK cells is regulated by activating and inhibitory signals resulting from interactions between their cell surface receptors and ligands expressed on potential targets. NK cells may destroy tumors directly, or may participate in antibody dependent cellular cytotoxicity (ADCC). The function of NK cells can be augmented by the use of drugs, cytokines, or through genetic modifications. NK cells may also be expanded, ex vivo, for use in adoptive immunotherapy. NKT cells possess features of both the innate and adaptive immune system, and express an invariant T cell receptor (iNKT cells) that recognizes glycolipid antigens in the context of the MHC class-I-like CD1d molecule. iNKT cells are also being utilized for cancer immunotherapy.