Abstract
Natural killer cells, or NK cells, are a type of cytotoxic lymphocyte critical to the innate immune system. The role that NK cells play is analogous to that of cytotoxic T cells in that they provide rapid responses to virus-infected cells and responses to tumor formation. Unmodified NK cells have long been used in various immunotherapies to treat different tumors, with only marginal success. However, in the last few years, NK cells modified to express chimeric antigen receptors (CAR-NK cells) have emerged as particularly ideal cellular platforms for antigen-specific antitumor agents. Unlike CAR-T cells, they do not elicit allogeneic responses or graft-versus-host disease and therefore can be administered to recipients with differing MHC expression. This article outlines protocols to obtain CD19-CAR-NK cells, focusing on the importance of obtaining and culturing a purified NK cell population and how to attain good transfection efficiency. © 2020 Wiley Periodicals LLC Basic Protocol 1: Purification and culture of adult peripheral blood and umbilical cord blood NK cells Basic Protocol 2: CD19-CAR lentiviral transduction of adult peripheral blood or umbilical cord blood NK cells Support Protocol: Production of lentiviral supernatant.