| 1. |
- Guldevall, Karolin, 1981-, et al.
(author)
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Microchip screening platform for assessment of cytotoxic effector cells
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Other publication (other academic/artistic)abstract
- Here we report a screening platform for assessment of the cytotoxic potential of individual natural killer (NK) or T cells within larger populations. Human primary NK cells or human Epstein-Barr virus (EBV)- specific T cells were distributed across a silicon-glass microchip containing 32 400 individual microwells loaded with target cells. Through fluorescence screening and automated image analysis the numbers of effector and live or dead target cells in each well could be assessed at different time-points after initial mixing. Cytotoxicity was also studied by time-lapse live-cell imaging in microwells quantifying the killing potential of individual NK cells. Although most resting NK cells (≈75%) were non-cytotoxic to the leukemia cell line K562, some NK cells were able to kill several (≥3) target cells within the 12 hours long experiment. We demonstrate that this assay can be used to enumerate and characterize cytotoxic cells, something that could find clinical applications, e.g. in the selection of donors for stem cell transplantation or generation of highly specific and cytotoxic cells for adoptive immunotherapy.
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| 2. |
- Hsu, Hsiang-Ting, et al.
(author)
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NK cells converge lytic granules to promote cytotoxicity and prevent bystander killing
- 2016
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In: Journal of Cell Biology. - : Rockefeller University Press. - 0021-9525 .- 1540-8140. ; 215:6, s. 875-889
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Journal article (peer-reviewed)abstract
- Natural killer (NK) cell activation triggers sequential cellular events leading to destruction of diseased cells. We previously identified lytic granule convergence, a dynein-and integrin signal-dependent movement of lysosome-related organelles to the microtubule-organizing center, as an early step in the cell biological process underlying NK cell cytotoxicity. Why lytic granules converge during NK cell cytotoxicity, however, remains unclear. We experimentally controlled the availability of human ligands to regulate NK cell signaling and promote granule convergence with either directed or nondirected degranulation. By the use of acoustic trap microscopy, we generated specific effector-target cell arrangements to define the impact of the two modes of degranulation. NK cells with converged granules had greater targeted and less nonspecific "bystander" killing. Additionally, NK cells in which dynein was inhibited or integrin blocked under physiological conditions demonstrated increased nondirected degranulation and bystander killing. Thus, NK cells converge lytic granules and thereby improve the efficiency of targeted killing and prevent collateral damage to neighboring healthy cells.
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| 3. |
- Vanherberghen, Bruno, et al.
(author)
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Classification of human natural killer cells based on migration behavior and cytotoxic response
- 2013
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In: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 121:8, s. 1326-1334
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Journal article (peer-reviewed)abstract
- Despite intense scrutiny of the molecular interactions between natural killer (NK) and target cells, few studies have been devoted to dissection of the basic functional heterogeneity in individual NK cell behavior. Using a microchip-based, time-lapse imaging approach allowing the entire contact history of each NK cell to be recorded, in the present study, we were able to quantify how the cytotoxic response varied between individual NK cells. Strikingly, approximately half of the NK cells did not kill any target cells at all, whereas a minority of NK cells was responsible for a majority of the target cell deaths. These dynamic cytotoxicity data allowed categorization of NK cells into 5 distinct classes. A small but particularly active subclass of NK cells killed several target cells in a consecutive fashion. These "serial killers" delivered their lytic hits faster and induced faster target cell death than other NK cells. Fast, necrotic target cell death was correlated with the amount of perforin released by the NK cells. Our data are consistent with a model in which a small fraction of NK cells drives tumor elimination and inflammation.
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