Semester of Graduation
Fall 2025
Degree
Master of Science (MS)
Department
Pathobiological Sciences
Document Type
Thesis
Abstract
Chimeric Antigen Receptor (CAR)-T cell therapy has transformed cancer treatment but still faces major limitations, especially against solid tumors. Deletion of Interleukin-2-inducible T-cell kinase (ITK), a non-receptor tyrosine kinase critical for T cell receptor signaling, has emerged as a promising intracellular target to boost CAR-T cell efficacy. While CRISPR-Cas9- mediated ITK knockout improves CAR-T memory and persistence, it compromises cell viability and scalability. Small-molecule ITK inhibitors offer a non-genetic approach but are limited by poor specificity and systemic toxicity.
To overcome these limitations, we developed peptide-based ITK inhibitors that can be co- delivered with the CAR-encoding gene, preserving T cell viability while enhancing therapeutic functions. ITK contains multiple domains critical for signal transduction, including SH2, SH3, and kinase domains. We constructed three phage display libraries each containing ~1.2 billion unique clones to identify peptides targeting either the SH2, SH3 or kinase domain of ITK. Selected peptides showed high specificity with minimal cross-reactivity to ITK homologs, surpassing small molecule ITK inhibitors. Kinase-targeting peptides inhibited ITK enzymatic activity. Interestingly, SH2-binding peptides also inhibited ITK kinase activity, suggesting a regulatory role for this non- catalytic domain.
To further enhance specificity and potency, we engineered, a multi-domain inhibitor that combines top-performing peptides targeting the SH3, SH2, and kinase domains. This multi-pronged strategy enables simultaneous disruption of multiple functional sites within ITK, offering a novel approach to fine-tune CAR-T cell signaling. Our approach represents a significant step toward next-generation CAR-T therapies with improved safety and efficacy.
Date
10-22-2025
Recommended Citation
JalaliFarahani, Melina, "ENHANCING CHIMERIC ANTIGEN RECEPTOR T CELL FUNCTION WITH MULTI-DOMAIN INHIBITORS OF INTERLEUKIN-2-INDUCIBLE T-CELL KINASE" (2025). LSU Master's Theses. 6235.
https://repository.lsu.edu/gradschool_theses/6235
Committee Chair
Veggiani, Gianluca