How is the CAR receptor introduced to the T cell?

To create CAR-T cells, the genetic material coding the engineered receptor must be delivered to and incorporated within the host T cell genome. Delivery can be accomplished through a variety of methods, including plasmid transfection and viral vector transduction, but stable gene transfer and transcription is required for sustained CAR surface expression. Stably transfected/transduced CAR-T cells can then be selected, expanded, and used for research or therapeutic purposes.1

Reference:
1. X. Wang and I. Rivière, “Clinical manufacturing of CAR T cells: foundation of a promising therapy,” Mol Ther Oncolytics 3:16015, 2016.