To engineer cells that can specifically target the central nervous system (CNS), we identified extracellular CNS-specific antigens, including components of the CNS extracellular matrix and surface molecules expressed on neurons or glial cells. Synthetic Notch receptors engineered to detect these antigens were used to program T cells to induce the expression of diverse payloads only in the brain. CNS-targeted T cells that induced chimeric antigen receptor expression efficiently cleared primary and secondary brain tumors without harming cross-reactive cells outside of the brain. Conversely, CNS-targeted cells that locally delivered the immunosuppressive cytokine interleukin-10 ameliorated symptoms in a mouse model of neuroinflammation. Tissue-sensing cells represent a strategy for addressing diverse disorders in an anatomically targeted manner.

To develop an effective and sustainable cell therapy for sickle cell disease (SCD), we investigated the feasibility of targeted disruption of the BCL11A gene, either within exon 2 or at the GATAA motif in the intronic erythroid-specific enhancer, using zinc finger nucleases in human bone marrow (BM) CD34+ hematopoietic stem and progenitor cells (HSPCs). Both targeting strategies upregulated fetal globin expression in erythroid cells to levels predicted to inhibit hemoglobin S polymerization. However, complete inactivation of BCL11A resulting from bi-allelic frameshift mutations in BCL11A exon 2 adversely affected erythroid enucleation. In contrast, bi-allelic disruption of the GATAA motif in the erythroid enhancer of BCL11A did not negatively impact enucleation. Furthermore, BCL11A exon 2-edited BM-CD34+ cells demonstrated a significantly reduced engraftment potential in immunodeficient mice. Such an adverse effect on HSPC function was not observed upon BCL11A erythroid-enhancer GATAA motif editing, because enhancer-edited CD34+ cells achieved robust long-term engraftment and gave rise to erythroid cells with elevated levels of fetal globin expression when chimeric BM was cultured ex vivo. Altogether, our results support further clinical development of the BCL11A erythroid-specific enhancer editing in BM-CD34+ HSPCs as an autologous stem cell therapy in SCD patients.