Extracellular vesicles in the TME of neuroblastoma: modulator of efficacious immunotherapies?

Abstract

Despite giving rise to improved survival rates in neuroblastoma, 40% of high-risk patients fail to respond or develop resistance to immunotherapy. Neuroblastoma poses a big challenge for immunotherapy by secretion of immunomodulatory proteins and extracellular vesicles (EVs) into the tumour microenvironment (TME). Therefore, we aim to investigate the optimal method to isolate extracellular vesicles from the secretome of neuroblastoma tumour organoids with the purpose of preserved functional activity of the EVs. We isolated EVs from 14 neuroblastoma tumour organoids and healthy reference cells by use of size exclusion chromatography (SEC) after which the EVs were characterised and quantified. We established the EVs preserved some functional capacity in co-culture with immune cells and demonstrated the isolation method is compatible with MS analysis of the EV protein composition. Thus this study establishes a suitable method to isolate functional EVs from tumour organoids, enabling further research into their potential immunosuppressive capacity in the TME of neuroblastoma.