Ex-vivo expansion of patient-derived PBMCs preferentially results in effector memory T-cell proliferation with restored autologous efficiency in HBV-HCC

BackgroundT-cell-based therapies achieved milestones in targeting solid tumors, such as hepatocellular carcinoma, by leveraging the cytotoxic potential of effector memory T-cells. However, a key challenge lies in the ex-vivo expansion of functional memory T-cells while simultaneously preventing over-differentiation into senescent TEMRA cells. MethodsPBMC derived from 10 HCC patients and two healthy donors were used for expansion in small bioreactors equipped with a permeable membrane for 2 weeks. During expansion, surface marker composition, cytokine and chemokine production were observed. Enriched T-cell subsets from three patients with chronic HBV infection were analysed in detail. We extracted the enriched complement of one chronically infected patient to elucidate the therapeutic potential. ResultsWe successfully expanded the effector T-cell subsets for all investigated samples and consistently enriched the cell amount over time. Subsequently, we showed that the expanded patient-derived T-cells showed functionality against autologous liver cancer-derived cells by inducing receptor and protein-mediated cell death. ConclusionWe showed the consistent ex-vivo expansion of T-cell subsets of initial patient-derived PBMCs. The enriched subsets exhibit cytotoxic functionality and shift to cytolytic TEMRA cells in an immune evasion setting in the context of chronic HBV-infected patient-derived liver cancer cells.