Generation of γδ T Cells Using iPSC Technology and Evaluation of Zoledronic Acid-Augmented γδ T Cell Therapy for Solid Tumours in a Multi-Organoid Immune-on-a-Chip

Gamma delta (γδ) T cells represent a promising candidate for off-the-shelf allogeneic solid tumour immunotherapy due to their immune surveillance in an MHC-independent manner. However, their low numbers in peripheral blood remain a significant barrier to clinical application. In the first part of this project, we explored the generation of γδ T cells from γδ T cell-derived induced pluripotent stem cells (γδ T-iPSCs). We demonstrated their potential as an alternative renewable source through sequential differentiation from γδ T-iPSCs into haematopoietic stem and progenitor cells (HSPCs) and subsequently into γδ T cells. The second part of this project assessed the anti-tumour activity of γδ T cells, particularly when combined with zoledronic acid (ZOL), an FDA-approved drug for bone disease. ZOL increases the susceptibility of tumour cells to γδ T cell killing by inhibiting the mevalonate pathway in tumour cells. This inhibition causes the accumulation of phosphoantigens, such as isopentenyl pyrophosphate (IPP) which γδ T cells recognise more effectively leading to stronger tumour cell targeting. To investigate ZOL-augmented γδ T cell therapy, we used three distinct 3D solid tumour models. First, co-culture assays with 3D tumour spheroids in suspension were assessed for inherent killing activity of the γδ T cells. Second, gel-embedded spheroids allowed assessment of γδ T cell’s tracking and killing abilities. Third, a Multi-organoid Immune-on-a-chip platform was developed to assess potential off-target effects by incorporating iPSC-derived cerebral, liver and heart organoids alongside tumour spheroids. This combined approach offers a physiologically relevant alternative to conventional 2D cancer models and animal experiments, improving predictive value and addressing ethical concerns. By integrating iPSC-derived γδ T cell generation with advanced 3D tumour models, this work demonstrates the potential of iPSC-derived γδ T cells as an alternative resource and establishes a framework for preclinical evaluation of ZOL-augmented γδ T cell therapy.