A significant change in the 5-hmCSeal signal is observed between UT-7 WT cells and cells carrying single or dual phospho-site substitution cells around the BCL11A gene enhancer region
An allogeneic blood stem cell transplantation is the only durable cure for sickle cell disease. Non-cell therapy approaches that target suppressor proteins of fetal hemoglobin gene (HBG) expression will provide the basis for novel therapies. Here we identify TET2 dioxygenase as a unifying regulator of both HBG suppressor BCL11A, and HBG activators HBBP1 and BGLT3 lncRNAs. Down regulation of TET2 functions by replacement of a single c-terminus phospho tyrosine residue is sufficient for activation of HBG by a mechanism that involves loss of TET2 binding with transcription factor GATA1 and redistribution of DNA hydroxymethylation in BCL11A enhancer and HBBP1/BGLT3 genes. By creating a transgenic sickle cell mouse in a Tet2 phospho tyrosine null background we demonstrate reactivation of fetal hemoglobin with resulting improvement in anemia and loss in sickle cell morphology and normalization of blood counts thereby identifying a mechanism for HBG activation without the need for gene editing approach. Overall design: 5-hmCSeal profiling of wildtype UT7 cells and their Crispr derivatives (Y1939A, Y1964A, and DM)  around the BCL11A gene enhancer region (+55, +58, and +62).