Development of Transgenic TCR-T cells for efficient cytolytic response in cancer immunotherapy 2075

Description Adoptive cell transfer (ACT) therapy is a promising approach for cancer treatment. However, attempts to utilize the patient’s tumor-infiltrating lymphocytes (TILs) revealed mixed results. This avenue also relies on pre-existing tumor-specific T-cells of sufficient quality. We used viral transduction to redirect peripheral blood T-cells to target tumor cells using α/β TCR genes with the desired specificity. However, this approach leads to lower cytolytic activity compared to high-quality cloned CD8 cells. This can be attributed to semi-random insertion of the TCR genes into the genome and α/β chain mispairing with endogenous TCR, resulting in a heterogenous transgenic TCR-T cell population with varying levels of TCR expression. To solve these problems, we used CRISPR-CAS9 editing to knock out endogenous α/β-TCR prior to viral transduction. This approach produced transgenic TCR T-cells with improved sensitivity and magnitude of response. To further improve the quality of TCR-T cells, we will insert transgenic TCR genes, specifically into endogenous TCR locus, using the CRISPR-CAS9 knock-in approach. This approach would result in consistently high levels of TCR expression on T cells due to the natural maintenance of endogenous TCR locus in the open state that supports continuous transcription. A comprehensive comparison of these design strategies will provide crucial information for transgenic TCR-T cell-based therapy and new insight into TCR signaling.