TMIC-28. TITLE: AN IMMUNE-RELATED, SEX-SPECIFIC T-CELL SIGNATURE IN GLIOBLASTOMA MICROENVIRONMENT WITH PROGNOSTIC IMPACT
Giulia Romagnoli, Martina Offi, Imerio Capone, Andrea Tavilla, Irene Canini, Caterina Lapenta, Mariachiara Buccarelli, Martina Giordano, Valentina Tirelli, Massimo Sanchez, Alessandra Fragale, Stefano Giannetti, Giovanni Maria Ceccarelli, Rina Di Bonaventura, Francesco Doglietto, Alessandro Olivi, Liverana Lauretti, Mauro Biffoni, Lucia Ricci-Vitiani, Roberto Pallini, Lucia Gabriele, Quintino Giorgio D’AlessandrisAbstract
BACKGROUND
Glioblastoma, IDH-wildtype (GBM), is the most prevalent and aggressive primary brain cancer with a poor prognosis. Immune checkpoint inhibitors (ICIs) have been explored in GBM with limited success, highlighting the need for a better understanding of the tumor microenvironment (TME). This study investigated whether the expression of specific immune checkpoints on tissue-resident memory T cells (Trm) predicts patient outcomes.
METHODS
In a single cohort observational study, tumor samples from 45 histologically confirmed GBM patients were processed to obtain single-cell suspensions. Multiparametric flow cytometry was used to analyze the correlation of Trm phenotypes with overall survival (OS) and progression-free survival (PFS). Univariate and multivariate analyses were conducted to assess the prognostic significance of Trm subsets.
RESULTS
Low frequency of exausted Trm expressing programmed cell death protein 1 (PD1) and T cell immunoglobulin and mucin domain-containing protein 3 (TIM3) was associated with better clinical outcomes. Multivariate analysis identified low CD8+CD103+PD1+TIM3+ Trm and Karnofsky performance status (KPS) ≥70 as the most significant independent prognostic factors for longer OS (hazard ratios—HR [95%CI]: 0.14 [0.04–0.52] p < 0.001, 0.39 [0.16–0.96] p = 0.04, respectively). Additionally, younger patients (<63 years) and males had distinct immune profiles affecting prognosis. Notably, the proportion of exausted CD8+CD103+PD1+ Trms had a prognostic correlate only in male patients, consistent with findings by other groups on the existance of gender-specific immune TME in GBM.
CONCLUSIONS
Further exploration of Trm-based immune profiling has the potential to shed light on GBM resistance to ICIs and to help in personalizing treatment strategies.