Efficient and Traceless Aptamer‐Based Serial Selection of Naïve and Early Memory CD8 T Cells for CAR T Cell Therapy

Abstract Chimeric antigen receptor (CAR) T cell therapies have shown clinical success in cancer treatment. However, the compositions of the final products can differ substantially between patients, leading to variable treatment responses. Recent studies suggest that CAR T cells manufactured from defined T cell subsets show greater potency and persistence and improved predictability of therapeutic efficacy. Current clinical‐scale selection of T cell subsets relies on antibody‐based magnetic activated cell sorting, which is costly and results in suboptimal product purity and yield, presenting a significant challenge for clinical translation. Here, a high‐affinity CD62L aptamer and a traceless, sequential selection system are reported for the high‐yield and high‐purity isolation of CD62L⁺CD8⁺ T cells without residual selection labels. It is demonstrated that multiple aptamer‐reversal agent pairs can be integrated into a magnetic platform for multi‐parameter and high‐throughput cell sorting. CAR T cells manufactured from aptamer‐selected CD62L⁺CD8⁺ T cells, encompassing naïve and early memory CD8 + T cells, exhibit distinct phenotypic and functional advantages compared to those manufactured from bulk CD8 + T cells. This aptamer‐based approach has the potential to improve the clinical efficacy of current adoptive T cell therapies by enabling precise and scalable selection of T cell subsets, with broad applications beyond T cell subset selection.