Background and Aims: Hepatic metastasis (HM) worsens cancer prognosis and impairs immunotherapy efficacy. While immune checkpoint inhibition (ICI) failure is attributed to cytotoxic T lymphocyte (CTL) apoptosis and deactivation, HM’s impact on adoptive cell transfer (ACT) remains poorly understood. We aim to define, mechanistically dissect, and potentially overcome HM-induced ACT suppression by targeting the fate and functional changes of transferred CTLs.
Methods: We employ dual-site metastatic murine models (HM vs. pulmonary metastasis [PM]) to elucidate HM-induced ACT suppression. SynNotch-labelled CTLs engaged with HM or PM will be isolated post-transfer, followed by scRNA-seq to identify candidate genes responsible for CTLs’ fate and functional changes within the HM microenvironment. Genetically modified CTLs targeting these genes will then be evaluated for their potential to overcome HM-induced suppression.
Results: We established robust and reproducible dual-site murine models with HM or PM via portal or tail vein injection. HM significantly impaired rejection of cognate subcutaneous tumours, confirming ACT suppression. SynNotch-based labelling enabled precise isolation of HM-experienced CTLs for single-cell transcriptomics, revealing differentially expressed genes linked to CTLs’ fate and functional changes. These candidate genes provide direct actionable targets to restore—and potentially enhance—CTL antitumor efficacy in metastatic settings.