TNF-NFkB-p53 axis restricts in vivo survival of hPSC-derived dopamine neuron (CRISPR screen)

First-in-human clinical trials illustrate the feasibility and translational potential of human pluripotent stem cell (hPSC)-based cell therapy in Parkinson's disease (PD). However, a major unresolved challenge is the extensive cell death following transplantation with <10% of grafted dopamine neurons surviving. Here, we performed a pooled CRISPR/Cas9 screen to enhance survival of postmitotic dopamine neurons in vivo. We identified TP53-mediated apoptotic cell death as major contributor to dopamine neuron loss and uncovered a causal link of TNFa-NF?B signaling in limiting cell survival. A surface marker screen enabled the purification of midbrain dopamine neurons obviating the need for genetic reporters. Combining cell sorting with adalimumab pretreatment, a clinically approved TNFa inhibitor, enabled efficient engraftment of postmitotic dopamine neurons leading to extensive re-innervation and functional recovery in a preclinical PD mouse model. Thus, transient TNFa inhibition may present a clinically relevant strategy to enhance survival of human PSC-derived lineages in PD and beyond. Overall design: CRISPR screen study of TP53 WT dopamine neurons, in vitro and in vivo