TALEN-mediated GR editing in Streptamer-selected CMV-specific CD8⁺ T cells. (A) Major histocompatibility complex class I Streptamers (HLA-A02) allow isolation of CMV-specific (NLV peptide) CD8⁺ T cells in high purity from donor blood leukocytes. (B) Primary T-cell transfection efficacy (>98%) and viability (>60%), using electroporation with in vitro transcribed mRNA. (C) Representative TALEN-induced nonhomologous end joining recombination mutagenesis in Streptamer-selected primary T cells by MiSeq analysis. (D) Western blot analysis of TALEN and GR expression before and after DEX enrichment of mutated cells. (E) Off-target site analysis from in silico prediction after next-generation sequencing. FSC-A, forward scatter area.