CD40LG gene replacement with a functional CD40LG transgene. (A) CD40LG cDNA gene replacement templates targeting the 5′UTR region of exon 1 of CD40LG: CD40LG[GFP.CD40L.3′UTR] (top) and CD40LG[GFP.CD40L.WPRE] (bottom). Total AAV packaging sizes are 4616 and 4234 bp, respectively. (B) Average HDR rate (percentage GFP+; n = 4 separate healthy male donors) of each gene-editing template in CD4+ T cells. (C) GFP (x-axis) and CD40L (y-axis) coexpression or (D) CD40-muIg binding in T cells edited with cDNA gene replacement templates. (Top row) Resting; (bottom) P/I activated. *Plots in panels C and D were generated at separate times, using different donor T cells.