Traceless aptamer-mediated isolation of CD8 T cells for chimeric antigen receptor T-cell therapy.

Chimeric antigen receptor T-cell therapies using defined product compositions require high-purity T-cell isolation systems that, unlike immunomagnetic positive enrichment, are inexpensive and leave no trace on the final cell product. Here, we show that DNA aptamers (generated with a modified cell-SELEX procedure to display low-nanomolar affinity for the T-cell marker CD8) enable the traceless isolation of pure CD8 T cells at low cost and high yield. Captured CD8 T cells are released label-free by complementary oligonucleotides that undergo toehold-mediated strand displacement with the aptamer.