How are T cells isolated and expanded?
Sustained T cell activation is needed for ex vivo expansion. This can be accomplished by co-incubating T cells with natural or artificial antigen-presenting cells (APCs). Alternatively, antibody-coated beads can deliver the necessary signals to the T cells, and they have become popular to both select for and activate T cells in a single step.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.