Production and large-scale expansion of functionally active NK cells suitable for use in immunotherapy of hematological and solid tumors

Natural killer cells (NK) are part of the innate immune system of the body and play an important role in the immune surveillance of foreign cells and the body’s own altered cells, including the transformed ones. The NK cells, without prior stimulation, can eliminate target cells which do not express their own MHC class I molecules or express stress-induced molecules. These basic, natural functions of the NK cells as a tool in the fight against malignant tumors have attracted particular attention. For this purpose, various approaches are used to increase the number and/or enhance the functional activity of the NK cells. One approach uses cytokines to selectively increase both the number and effectiveness of the NK cell antitumor function. Another approach focuses on checkpoint inhibitors targeting the NK cell receptor. Bispecific and trispecific activators have been developed to enhance the specific immune response by cross-linking specific tumor antigens with effector cells. In addition, methods of adoptive transfer of the NK cells have shown promising results, however, a fairly large volume of cell mass is required there.