Date of Award
2026
Degree Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Cell Biology, Neurobiology and Anatomy
First Advisor
Michael Nishimura
Abstract
T cell receptor (TCR) gene-modified T cells are an evolving area of adoptive cell therapy (ACT) for cancer immunotherapy. Many clinical studies have been performed with varying efficacy, and in collaboration with the NIH, our lab performed a clinical trial using HERV-E TCR transduced T cells for the treatment of metastatic Renal Cell Carcinoma (RCC). This therapy was effective, conferring clinical responses in 66% of patients, however no complete responses were observed, demonstrating the need to improve this T cell therapy to improve clinical outcomes. Methods to improve the TCR expressed in TCR transduced T cells include affinity maturation, structural modifications and TCR chain pairing increases. Affinity maturation and structural modifications can result in cross reactivity and/or adverse events due to changes in the antigen binding domain of the TCR. TCR chain pairing modifications do not result in changes to antigen recognition and instead focus on ensuring proper TCR pairing prior to surface expression, preventing mispairing of the introduced TCR with the endogenous TCR. Previous studies determined codon optimization, switching the human TCR constant regions with the mouse TCR constant regions, and the inclusion of Leucine Zipper cassettes within the TCR to increase TCR chain pairing and surface expression, with increased specific T cell function. These modifications were introduced into the HERV-E TCR and TCR expression, T cell function, and antigen specificity were assessed in multiple ways to determine the impact of increased HERV-E TCR expression in transduced T cells. Ultimately, the inclusion of Leucine Zipper cassettes in the HERV-E TCR was found to improve in vitro T cell function without inducing cross reactivity, however these modifications did not significantly impact survival in tumor-bearing mice in in vivo models. These results suggest the inherent biology of the T cells is critical to long-term function and persistence for anti-tumor efficacy. An avenue to modify the biology of TCR transduced T cells is differential preparation of T cells using IL-7 culturing. Traditional T cell conditioning is performed using an activation step and proliferative cytokines, such as IL-2, to activate, proliferate, and differentiate T cells prior to the introduction of the TCR transgene. These methods, however, can limit the persistence and function of TCR transduced T cells due to the shortening of telomeres, the induction of refractory terminally differentiated T cells, and activation-induced cell death following antigen stimulation. IL-7 culturing without CD3 activation or other cytokines has been shown to increase persistence of CD19 Chimeric Antigen Receptor (CAR) transduced T cells and improve anti-tumor function in tumor-bearing mice. In combination with increased TCR pairing, IL-7 culturing enhances the longevity of HERV-E TCR transduced T cells by promoting a naïve and stem-cell memory phenotype of the T cells, reducing inhibition pathway expression, and prolonging anti-tumor function of transferred T cells in tumor-bearing mice. Altogether, the results of the studies described increased anti-tumor efficacy of IL-7 cultured HERV-E TCR transduced T cells compared to CD3 activated transduced T cells, accompanied by a reduction in GvHD in tumor-bearing mice, suggesting increased tolerability of IL-7 cultured T cells. IL-7 culturing is not limited to increasing efficacy of the HERV-E TCR and can be expanded to prepare T cells expressing TCRs or CARs specific for many cancers or diseases. Therefore, IL-7 culturing may serve as an alternative preparation method for T cell immunotherapies by producing less differentiated therapies with more potential in vivo to confer better clinical outcomes.
Recommended Citation
Quinn, Suzanne, "Strategies to Improve T Cell Receptor Transduced T Cell Function and Longevity for Immunotherapy" (2026). Dissertations. 4324.
https://ecommons.luc.edu/luc_diss/4324
