The Use of a New Transposon Vector without CH2CH3 Further Enhances the CAR Expression in PB-Modified T Cells
(A) Schematic representation of the transposon plasmid encoding CD19.CAR (pIRII-CAR.CD19-28-ζ) with (original vector) or without (short vector) IgG-CH2CH3 hinge region. The size of the CD19.CAR plasmid was reduced from 6,438 bp to 5,798 bp by depleting the IgG1-CH2CH3 spacer. Plasmid and insert sizes of each vector are also shown. (B) Ex vivo expansion of ACE CAR-T with the original or the short transposon vector. PBMCs were transfected with either the original or the short transposon vector encoding CD19.CAR and cultured using the ACE CAR-T method. Cell numbers were determined by a trypan blue exclusion assay on days 7 and 14. The data are presented as the mean ± SD of experiments from nine donors. (C and D) CD19.CAR expression on PB-modified T cells was examined by flow cytometry. Representative results (C) and summary results (D) from nine donors are shown.