Donor CD19 CAR T cells exert potent graft-versus-lymphoma activity with diminished graft-versus-host activity

Allogeneic chimeric antigen receptor (CAR) T cells are capable of inducing graft-versus-host disease (GVHD) in recipients, yet this is not commonly seen in the clinic. Marcel van den Brink, Michel Sadelain and colleagues show that alloreactive CAR T cells have reduced effector function due to signaling through the CAR and T cell receptor, resulting in reduced GVHD, while the graft-versus-leukemia effect is maintained by non-alloreactive CAR T cells.