184 Identifying murine tumor models that capture the differentiation trajectory of tumor infiltrating lymphocytes (TILs)

A better understanding of tumor infiltrating leukocyte (TIL) differentiation is necessary to advance therapeutic strategies and inform melanoma patient outcomes. We have previously identified that the transcriptome CD8+ TILs can be placed on a spectrum early activation late memory states. Halting in associated with poor response immune checkpoint blockade (ICB), whereas progression towards resident states was productive ICB responses improved survival However, it remains unknown which, if any murine models currently being used model T cell demonstrate this trajectory. Identification such would allow us study signals driving differentiation. queried public dataset where OT-1 cells were activated vitro transferred into B16-OVA bearing mice presence or absence ICB. found treated which exhibited control had upregulated gene programs positive patients, as well persistent signatures memory. Control nonresponse activation, demonstrating faithfully captured trajectory we for human TILs. Future work will extend analysis include other congenic varied immunogenicity YUMM, YUMMER, examine cues shift states, hopes identifying rational combinations