BACH2 regulates T cell lineage state to enhance CAR T cell function

Nearly all chimeric antigen receptors (CARs) signal in the absence of antigen, referred to as 'tonic signaling'. Tonic signaling of CARs containing 41BB domains enhances T cell fitness and function, in contrast to the exhaustion driven by CD28-containing CARs. Here we show that 41BB induces BACH2, a transcriptional regulator that directs stem and memory programs. Overexpression of BACH2 successfully prevented exhaustion but locked CAR T cells in a quiescent state. We linked BACH2 to a degradation domain to tune BACH2, enabling us to prevent exhaustion while enabling potent effector function that broadly enhanced the long-term efficacy of CAR T cells targeting liquid and solid tumors. Through interrogation of…

• DR
  Damon Runyon Cancer Research Foundation
• VF
  V Foundation for Cancer Research
• CD
  Children's Discovery Institute