How do I select, expand, and store CAR-T cells?

After isolation, selection, and gene transfer, T cells can be selected again based on CAR expression levels and stability. Selected CAR-T cells are then expanded in cell culture until the desired titers have been achieved, upon which the cells are harvested and either used or placed into storage.1

The final CAR-T cell product is evaluated using a list of criteria that varies slightly depending on the method of CAR gene transfer employed. In general, CD3 expression (to confirm T cell phenotype), CAR expression (to confirm successful gene transfer), and in vitro cytotoxic activity are used to assess CAR-T cell purity and potency, while bacterial/endotoxin presence is used to assess safety. Other factors which may be examined include replication-competent viral presence and residual levels of beads and/or antigen presenting cells (APCs).1

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