Presenter: Austin Hansen
Authors: Austin Hansen, Christopher Haynie, Kiara Whitley, Michelle Townsend, Stella Meier, K O'Neill, K Scott Weber
Faculty Advisor: Scott Weber
Institution: Brigham Young University
Effective immunotherapeutic targeting of cancer cells requires identification of specific antigenic differences between cancerous and healthy cells. Hypoxanthine Guanine Phosphoribosyl Transferase (HPRT) is a cytoplasmic enzyme involved in the DNA salvage pathway for DNA synthesis. Certain cancers (e.g., prostate and breast) upregulate and express HPRT on the cell membrane, making HPRT a potential cancer biomarker for cancer immunotherapies. Antibodies specific for unique cancer proteins are critical to develop targeted cancer immunotherapies. Using a yeast display library and cell sorting, we selected for high-affinity human scFv antibodies against HPRT that can be utilized in chimeric antigen receptor (CAR) T cell therapies and antibody-dependent therapeutic approaches. Our initial screening identified 11 potential clones that bind to HPRT at 100 nM concentration. Quantification of binding affinity and specificity will determine the best clones that we will transfer into a CAR T cell construct to evaluate CAR T cell cytotoxicity. Thus, we have isolated and are characterizing 11 HPRT specific clones for their ability to target cancer cells without destroying healthy cells.