Therapeutic effects against high-grade glioblastoma mediated by engineered induced neural stem cells combined with GD2-specific CAR-NK.

PURPOSE: High-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. METHODS: iNSCs cells expressing HSV-TK (iNSCsTK) and GD2-specific CAR-NK92 (GD2NK92) were generated from PBMC-derived iNSCs and NK92 cell lines, respectively. The anti-tumor effect of iNSCsTK and the combinational therapeutics of iNSCsTK and GD2NK92 were evaluated by GBM cell line using in vitro and in vivo experiments. RESULTS: PBMC-derived iNSCsTK 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). iNSCsTK/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 iNSCsTK/GCV and GD2NK92 against GBM was investigated. This approach displayed a more significant anti-tumor effect in vitro and in xenograft tumor mice. CONCLUSIONS: PBMC-derived iNSCsTK showed a significant tumor-tropic migration and an effective anti-tumor activity with GCV in vitro and in vivo. In addition, combined with GD2NK92, iNSCsTK therapeutic efficacy improved dramatically to prolong the tumor-bearing animal model's median survival.

Rosai-Dorfman disease with spinal and multiple intracranial involvement: a case report and literature review.

Rosai-Dorfman disease (RDD) is a condition of unknown etiology, and characterized by the proliferation of histiocytes. RDD most commonly affects lymph nodes, and central nervous system (CNS) involvement is rare. Here, we describe the case of a 43-year-old man who presented with an intradural tumour of the thoracic spine. The patient underwent a laminectomy for tumour resection and pathology results diagnosed the tumour as a RDD. Two years later, brain magnetic resonance imaging (MRI) revealed multiple intracranial dural-based lesions. Prednisolone treatment was initiated and led to resolution of the disease. We reviewed the literature to the investigate clinical characteristics, imaging features, diagnosis and treatment protocols pertaining to such cases.

Dopaminergic precursors differentiated from human blood-derived induced neural stem cells improve symptoms of a mouse Parkinson's disease model.

Autologous neural stem cells (NSCs) may offer a promising source for deriving dopaminergic (DA) cells for treatment of Parkinson's disease (PD). Methods: By using Sendai virus, human peripheral blood mononuclear cells (PBMNCs) were reprogrammed to induced NSCs (iNSCs), which were then differentiated to dopaminergic neurons in vitro. Whole-genome deep sequencing was performed to search for mutations that had accumulated during the reprogramming and expansion processes. To find the optimal differentiation stage of cells for transplantation, DA precursors obtained at various differentiation time points were tested by engraftment into brains of naïve immunodeficient mice. At last, the safety and efficacy of iNSC-derived DA precursors were tested by transplantation into the striatum of immunodeficient PD mouse models. Results: PBMNC-derived iNSCs showed similar characteristics to fetal NSCs, and were able to specifically differentiate to DA neurons with high efficiency in vitro. The sequencing data proved that no harmful SNVs, Indels and CNVs were generated during the reprogramming and expansion processes. DA precursors obtained between differentiation day 10 to 13 in vitro were most suitable for transplantation when a balanced graft survival and maturation were taken into account. Two weeks after transplantation of DA precursors into mouse PD models, the motor functions of PD mice started to improve, and continued to improve until the end of the experiments. No graft overgrowth or tumor was observed, and a significant number of A9-specific midbrain DA neurons were surviving in the striatum. Conclusion: This study confirmed the efficacy of iNSC-derived DA precursors in a mouse PD model, and emphasized the necessity of genomic sequencing and vigorous safety assessment before any clinical translation using iNSCs.

Conversion of adult human peripheral blood mononuclear cells into induced neural stem cell by using episomal vectors.

Human neural stem cells (NSCs) hold great promise for research and therapy in neural diseases. Many studies have shown direct induction of NSCs from human fibroblasts, which require an invasive skin biopsy and a prolonged period of expansion in cell culture prior to use. Peripheral blood (PB) is routinely used in medical diagnoses, and represents a noninvasive and easily accessible source of cells. Here we show direct derivation of NSCs from adult human PB mononuclear cells (PB-MNCs) by employing episomal vectors for transgene delivery. These induced NSCs (iNSCs) can expand more than 60 passages, can exhibit NSC morphology, gene expression, differentiation potential, and self-renewing capability and can give rise to multiple functional neural subtypes and glial cells in vitro. Furthermore, the iNSCs carry a specific regional identity and have electrophysiological activity upon differentiation. Our findings provide an easily accessible approach for generating human iNSCs which will facilitate disease modeling, drug screening, and possibly regenerative medicine.

Autologous iPSC-derived dopamine neuron transplantation in a nonhuman primate Parkinson's disease model.

Autologous dopamine (DA) neurons are a new cell source for replacement therapy of Parkinson's disease (PD). In this study, we tested the safety and efficacy of autologous induced pluripotent stem cell (iPSC)-derived DA cells for treatment of a cynomolgus monkey PD model. Monkey bone marrow mesenchymal cells were isolated and induced to iPSCs, followed by differentiation into DA cells using a method with high efficiency. Autologous DA cells were introduced into the brain of a cynomolgus monkey PD model without immunosuppression; three PD monkeys that had received no grafts served as controls. The PD monkey that had received autologous grafts experienced behavioral improvement compared with that of controls. Histological analysis revealed no overgrowth of grafts and a significant number of surviving A9 region-specific graft-derived DA neurons. The study provided a proof-of-principle to employ iPSC-derived autologous DA cells for PD treatment using a nonhuman primate PD model.