Chimeric Antigen Receptor-Induced Bcl11b Suppression Propagates Natural Killer-Like Cell Development

The transcription factor B Cell CLL/Lymphoma 11B (BCL11B) is indispensable for T lineage development of lymphoid progenitors. Here we show that chimeric antigen receptor (CAR) expression early in ex vivo generated lymphoid progenitors suppresses Bcl11b, leading to suppression of T cell-associated gene expression and acquisition of natural killer (NK) cell-like properties. These results give important insights into differentiation of murine and human lymphoid progenitors driven by synthetic CAR transgene-expression and inform the potential use of ex vivo generated CARiK cells as a broadly applicable product for targeted immunotherapy. Microarray data analysis of sorted human CAR-engineered lymphoid progenitors (h1928z3: n=3; h19delta: n= 5; h1928z3 + hCD19: n= 3) from OP9-DL1 in vitro cultures on day 18. Human CD34+ HSPCs derived from umbilical cord blood samples were engineered with a CD28-based second-generation human CAR targeting human CD19 (h1928z3) or a non-signaling control CAR (h19delta) and pre-differentiated on OP9-DL1 stromal cells in vitro. For CAR stimulation, irradiated CD19+ Daudi cells were added during the culture (h1928z3_stim).