Generation of Human iNKT Cell Lines

Natural killer T (NKT) cells comprise an important immunoregulatory T cell subset and express cell surface proteins characteristic of both natural killer cells and T cells. Invariant NKT (iNKT) cells are activated by lipid antigen presented in the context of CD1d molecules, in contrast to classic T cell subsets, which recognize peptide antigens presented by MHC molecules. Following activation, iNKT cells rapidly secrete large amounts of cytokines and can lyse tumor cells and virally infected cells; however, iNKT cells are reduced in patients with autoimmune disease and cancer. The potential to characterize and investigate the prospective use of iNKT cells for therapeutic purposes has significantly increased with the ability to stimulate and expand human iNKT cells. In this protocol, we describe a method to generate and propagate primary human iNKT cells. Specifically, primary iNKT cells were isolated from human peripheral blood mononuclear cells (PBMC), and then expanded periodically with irradiated α-GalCer loaded autologous immature dendritic cells (DC) in the presence of human IL-2.