Resisting Resistance: Towards Unravelling the Secrets of Cellular Immunotherapy

Abstract

The field of immune-oncology, and the development of a wide range of immunotherapy products that stemmed from it, has dramatically transformed the survival chances for many cancer patients. Nonetheless, there is a large share of patients that does not yet benefit from this success, either due to having difficult to target (solid) tumour types, or through the development of resistance during treatment. Due to the complexity of both cancer and the nature of immunotherapy products, there is a great need to develop novel methods that will allow us to study immune-cancer interactions in a simplified, controlled setting. In this thesis work, we have described optimal protocols to derive breast cancer organoid models (Chapter 2), which have further been used to study engineered immune cell product behaviour in the context of immune-organoid co-cultures (Chapter 4), and furthermore for studying processes underlying sensitivity and resistance to these cellular immunotherapy products (Chapter 5). Additionally, we have provided a thorough overview on the contributions of the field of 3D imaging to our understanding of cancer biology and treatment response (Chapter 3). Most excitingly, we have developed several novel tools to study both immunotherapy products and the tumours they target in unprecedented detail. With our imaging method and associated computational analysis platform called BEHAV3D (Chapter 4), we have provided a revolutionary method to study the behaviour of engineered immune cells, revealing that these products contain a mixture of cells with different behaviours, complex interactions, and (serial) killing capacities. With our newly developed method and analysis pipeline to detangle tumour heterogeneity called FUN-CLON (Chapter 5), we were able to explore the extensive landscape of factors influencing response to engineered T cell therapy, revealing several recurring profiles of responding and not responding cell states and characteristics. Together, these tools offer exciting opportunities for both preclinical and clinical applications, with the aim of further guiding cellular immunotherapy product development and improving patient outcomes.