To reduce the cost of CD8+ T cell isolation for CAR-T manufacturing and eliminate residual antibody from microbead techniques, Kacherovsky and Cardle et al. used an iterative selection process to identify DNA aptamers that selectively bind CD8α with high affinity. Complementary oligonucleotide binding to aptamer disrupted secondary structure by strand displacement and released bound CD8+ T cells. CD8+ T cells isolated from blood using aptamers or standard CD8 microbeads had comparable yield and purity and, when manufactured into CAR-T cells, displayed similar gene expression and antitumor efficacy in a mouse model of B cell lymphoma.
Contributed by Alex Najibi
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. We also show that chimeric antigen receptor T cells manufactured from these cells are comparable to antibody-isolated chimeric antigen receptor T cells in proliferation, phenotype, effector function and antitumour activity in a mouse model of B-cell lymphoma. By employing multiple aptamers and the corresponding complementary oligonucleotides, aptamer-mediated cell selection could enable the fully synthetic, sequential and traceless isolation of desired lymphocyte subsets from a single system.
Author Info: (1) Department of Bioengineering, University of Washington, Seattle, WA, USA. (2) Department of Bioengineering, University of Washington, Seattle, WA, USA. Ben Towne Center for Chi
Author Info: (1) Department of Bioengineering, University of Washington, Seattle, WA, USA. (2) Department of Bioengineering, University of Washington, Seattle, WA, USA. Ben Towne Center for Childhood Cancer Research, Seattle Children's Research Institute, Seattle, WA, USA. (3) Department of Bioengineering, University of Washington, Seattle, WA, USA. (4) Department of Bioengineering, University of Washington, Seattle, WA, USA. (5) Ben Towne Center for Childhood Cancer Research, Seattle Children's Research Institute, Seattle, WA, USA. (6) Department of Laboratory Medicine, University of Washington, Seattle, WA, USA. (7) Department of Bioengineering, University of Washington, Seattle, WA, USA. michael.jensen@seattlechildrens.org. Ben Towne Center for Childhood Cancer Research, Seattle Children's Research Institute, Seattle, WA, USA. michael.jensen@seattlechildrens.org. (8) Department of Bioengineering, University of Washington, Seattle, WA, USA. spun@uw.edu.
