Immunotherapy is a highly promising treatment option for cancer. At present, only a small proportion of cancer patients benefits from immunotherapeutic interventions. There is an unmet need to... Show moreImmunotherapy is a highly promising treatment option for cancer. At present, only a small proportion of cancer patients benefits from immunotherapeutic interventions. There is an unmet need to understand which factors determine a patient’s response to immunotherapy as well as to develop novel immunotherapeutic approaches that address shortcomings of current immunotherapies.In this thesis, we have performed an unprecedented characterization of immune cell subsets participating in anti-tumor responses in colorectal cancer and pancreatic ductal adenocarcinoma with different single-cell technologies. Most cancer immunology research studied the role of cytotoxic T cells in both cancer types, while a comprehensive analysis of both innate and adaptive components of cancer immunity was largely lacking. With such an approach, we demonstrated an important involvement of understudied unconventional (γδ T cells) and innate (innate lymphoid cells (ILCs)) immune effector cells in anti-tumor immunity. These immune subsets displayed cytotoxic activity and showed potential for therapeutic exploitation. Further studies will focus on their functional characterization and potential reconversion into a therapeutic agent.This thesis resulted from the collaboration between research groups led by Noel de Miranda (Pathology, LUMC) and Frits Koning (Immunology, LUMC), and underscores the relevance of applying single-cell technologies for the study of complex biological systems. Show less
Several studies have highlighted the uniqueness of the human immune system in early life. Due to the scarceness of human fetal tissues and technical limitations, a system-wide and detailed... Show moreSeveral studies have highlighted the uniqueness of the human immune system in early life. Due to the scarceness of human fetal tissues and technical limitations, a system-wide and detailed phenotypical characterization of the composition and development of the human fetal immune system was lacking. Here, I delineate the composition and development of the human fetal immune system using an array of advanced high-throughput technologies. First, mass cytometry analysis of the innate lymphoid cells revealed a previously unrecognized subset named int-ILC in the fetal intestine, which can give rise to NK cells and ILC3s. Moreover, by combining the acquired datasets from (imaging-) mass cytometry, single-cell RNA-sequencing and TCR sequencing with advanced computational analysis tools and functional analysis this revealed that memory-like CD4+ T cells were already generated in the developing human fetal intestine, indicative of in utero exposure to foreign antigens. Additionally, (imaging-) mass cytometry analysis of the immune cells in the fetal intestine, spleen and liver revealed an early-life immune compartmentalization in these different fetal tissues. Overall, our results deepens the understanding of prenatal immunity and may ultimately be useful for the development of “early” intervention strategies to prevent the development of immune mediated diseases later in life. Show less
