Multiparametric Detection of Effects of TILs and Oncolytic Virotherapy on Xenograft Mouse Model of Glioblastoma.

Background/Objectives: Glioblastoma (GBM) is an aggressive primary brain tumor with dismal prognosis and limited treatment options. Immunotherapy, including personalized approaches using tumor-infiltrating lymphocytes (TILs) and allogeneic natural (NK) or engineered killer cells (chimeric antigen receptor NK, NK-CAR), and oncolytic viruses (OV), has shown some potential in GBM. Combining different therapeutic strategies may enhance treatment efficacy. Here, we present a xenograft GBM mouse model with multiparametric detection for various immunotherapy research applications. Methods: In a xenograft GBM NOD-Prkdcs scid Il2rgem1/Smoc (NSG) mouse model based on orthotopic transplantation of patient-derived GBM cultures retaining tumor heterogeneity, intravenous and intratumor immunotherapeutic interventions by TIL and OV therapy were performed. Xenograft engraftment was evaluated using intravital MRI; delivery of OV and TILs to the tumor and changes in the tumor and peritumoral space were assessed using intravital confocal microscopy; and metabolic and structural changes in the tumor and peritumoral environment were assessed via fluorescence lifetime imaging microscopy (FLIM) and optical coherence tomography (OCT). The intravital imaging data were compared with the results of preliminary and final histological and immunocytochemical data. Results: Both OV and TILs demonstrated tumor-specific targeting and delivery across the blood-brain barrier. Further, we showed that in this model the xenograft response to both therapeutic treatments can be assessed using FLIM and OCT. Conclusions: Overall, this work presents an optimized mouse model suitable for assessing the effect of combined TIL immunotherapy and OV on GBM in translational studies.