<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "Functional Phenotyping of Natural Killer Cells by Droplet Microfluidics"^^ . "Cytotoxic immune cells, such as Natural Killer (NK) cells, are key players \r\ninvolved in the detection and elimination of malignant cells. Consequently, they \r\nhold significant promise for use in cell-based cancer immunotherapies. While \r\ntranslation into clinical practice is ongoing, much remains to be understood\r\nabout how and under which conditions NK cells can effectively kill target cancer \r\ncells. In contact with target cells, a heterogeneous cytotoxic response can be \r\nobserved where the majority of NK cells can remain unresponsive, while others \r\nwill deliver a cytotoxic hit. Remarkably, a small fraction of NK cells will kill \r\nseveral target cells in a row – an ability termed serial killing.\r\nIn this thesis, I developed a modular droplet microfluidic pipeline to \r\nsuccessfully resolve this phenomenon on a single-cell level. Towards this end, \r\nsingle primary human NK cells are co-encapsulated with several target cells into \r\npicoliter-sized droplets allowing the observation and quantification of\r\ncytotoxicity and serial killing behavior. Moreover, I developed an advanced high-throughput dielectrophoretic droplet sorter to isolate serial killing NK cells, \r\nthereby providing a missing link between the droplet microfluidic assay and \r\nother non-microfluidic techniques. I solved key engineering problems related to \r\nthe reliability, accuracy and throughput of the droplet sorting resulting in a \r\nplatform called MultiCell-Sort: a generalized tool that allows advanced \r\nscreening experiments based on cell-cell interactions beyond the application in \r\nserial killing.\r\nLeveraging the capabilities of MultiCell-Sort platform, the ultimate goal \r\nof my doctoral work was to shed light on the reasons for the heterogeneous \r\ncytotoxic response of NK cells. First, I identified an array of surface markers \r\nvia flow cytometry to provide a high-level signature of the serial killing subset. \r\nIV\r\nTo investigate what molecular fingerprints and regulators are associated with \r\nthe serial killing phenotype, I performed single cell RNA sequencing, analyzing \r\ntranscriptomic profiles of serial killing versus non-cytotoxic NK cells. I could \r\nshow that serial killing NK cells undergo metabolic reprogramming during \r\ntarget cell exposure, engaging in the Warburg effect. Multiple indicators point \r\nto the transcription factor Myc as the central effector of this switch. \r\nFurthermore, trajectory analysis of the transcriptome dataset revealed a rather \r\nsmall population among naïve, unstimulated NK cells that exhibit a \r\ndevelopmental trajectory towards the serial killing phenotype and therefore \r\nmatch the description of a serial killing precursor population. Given their gene \r\nexpression profile, I hypothesize that these potential precursors might be primed \r\nby Myc and upstream regulators to respond rapidly to IL2 stimulation and gain \r\nthe serial killing capacity. In the future, a preselection of serial killing precursor \r\ncells and validation of their superior anti-tumor efficacy could yield in an \r\nimproved population that could be further expanded. Second, developing \r\nstrategies to induce a Myc-driven switch across bulk populations of NK cells \r\ncould broadly boost their cytotoxicity. Taken together, these insights open up \r\navenues to enhance NK cell cytotoxicity that could be translated to advance\r\nNK cell-based cancer immunotherapies."^^ . "2026" . . . . . . . "Florian Felix Valentin"^^ . "Aubermann"^^ . "Florian Felix Valentin Aubermann"^^ . . . . . . "Functional Phenotyping of Natural Killer Cells by Droplet Microfluidics (PDF)"^^ . . . "Functional Phenotyping of Natural Killer Cells by Droplet Microfluidics (Other)"^^ . . . . . . "Functional Phenotyping of Natural Killer Cells by Droplet Microfluidics (Other)"^^ . . . . . . "Functional Phenotyping of Natural Killer Cells by Droplet Microfluidics (Other)"^^ . . . . . . "Functional Phenotyping of Natural Killer Cells by Droplet Microfluidics (Other)"^^ . . . . . "HTML Summary of #37099 \n\nFunctional Phenotyping of Natural Killer Cells by Droplet Microfluidics\n\n" . "text/html" . .