Polyclonal expansion of functional tumor-reactive lymphocytes infiltrating glioblastoma for personalized cell therapy

Tumor-infiltrating lymphocyte (TIL)-therapy has received FDA approval for the treatment of advanced melanoma and shows potential for broader applications in solid tumors, including glioblastoma. In this study, tumor-reactive TILs (tr-TILs) are isolated and enriched for CD137 expression from cavitron ultrasonic aspirator (CUSA) emulsions of 161 adult patients diagnosed with diffuse gliomas. Tr-TILs are successfully expanded in 87 out of the 161 patients, reflecting an expansion rate of 54%. Notably, the presence of IDH1 mutation and the cumulative dose of steroids are identified as significant negative predictors of expansion efficacy. The expanded tr-TILs exhibit distinct phenotypic and molecular dysfunctional features yet show upregulated expression of progenitor/memory-like markers and polyclonal T-cell receptors. Importantly, these tr-TILs demonstrate specific antitumor reactivity against autologous tumor cells in both in vitro and in vivo xenograft models. These findings provide a compelling background for a personalized immunotherapeutic approach while tackling one of the most significant challenges in oncology. TCRvb sequencing of 10 representative tr-TILs samples expanded in vitro to characterize their clonotypic profiles.