PurposeHigh-grade glioblastoma is extremely challenging to treat because of its aggressiveness and resistance to conventional chemo- and radio-therapies. On the contrary, genetic and cellular immunotherapeutic strategies based on the stem and immune cells are emerging as promising treatments against glioblastoma (GBM). We aimed to developed a novel combined immunotherapeutic strategy to improve the treatment efficacy using genetically engineered PBMC-derived induced neural stem cells (iNSCs) expressing HSV-TK and second-generation CAR-NK cells against GBM.MethodsiNSCs cells expressing HSV-TK (iNSCs(TK)) and GD2-specific CAR-NK92 (GD2NK92) were generated from PBMC-derived iNSCs and NK92 cell lines, respectively. The anti-tumor effect of iNSCs(TK) and the combinational therapeutics of iNSCs(TK) and GD2NK92 were evaluated by GBM cell line using in vitro and in vivo experiments.ResultsPBMC-derived iNSCs(TK) possessed tumor-tropism migration ability in vitro and in vivo, which exhibited considerable anti-tumor activity via bystander effect in the presence of ganciclovir (GCV). iNSCs(TK)/GCV could slow GBM progression and prolong median survival in tumor-bearing mice. However, the anti-tumor effect was limited to single therapy. Therefore, the combinational therapeutic effect of iNSCs(TK)/GCV and GD2NK92 against GBM was investigated. This approach displayed a more significant anti-tumor effect in vitro and in xenograft tumor mice.ConclusionsPBMC-derived iNSCs(TK) showed a significant tumor-tropic migration and an effective anti-tumor activity with GCV in vitro and in vivo. In addition, combined with GD2NK92, iNSCs(TK) therapeutic efficacy improved dramatically to prolong the tumor-bearing animal model's median survival.