LEF1 Drives a Central Memory Program and Supports Antitumor Activity of Natural Killer T Cells

Va24-invariant natural killer T cells (NKT) possess innate anti-tumor properties that can be exploited for cancer immunotherapy. We have shown previously that the CD62L+ central memory-like subset of these cells drives the in vivo antitumor activity of NKTs, but molecular mediators of NKT central memory differentiation remain unknown. Here, we demonstrate that relative to CD62L- cells, CD62L+ NKTs express a higher level of the gene encoding the Wnt/b-catenin transcription factor lymphoid enhancer binding factor 1 (LEF1) and maintain active Wnt/b-catenin signaling. CRISPR/Cas9-mediated LEF1 knockout reduced CD62L+frequency after antigenic stimulation, whereas Wnt/b-catenin activator Wnt3a ligand increased CD62L+ frequency. LEF1 overexpression pro-moted NKT expansion and limited exhaustion following serial tumor challenge and was sufficient to induce a central memory- like transcriptional program in NKTs. In mice, NKTs expressing a GD2-specific chimeric-antigen receptor (CAR) with LEF1 demonstrated superior control of neuroblastoma xenograft tumors compared with control CAR-NKTs. These results iden-tify LEF1 as a transcriptional activator of the NKT central memory program and advance development of NKT cell-based immunotherapy.