Nienke Vrisekoop

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Neutrophils are essential effector cells of the innate immune response and are indispensable for host defense. Apart from their antimicrobial functions, neutrophils inform and shape subsequent immunity. This immune modulatory functionality might however be considered limited because of their generally accepted short lifespan (< 1 day). In contrast to the(More)
In mice, recent thymic emigrants (RTEs) make up a large part of the naïve T cell pool and have been suggested to be a distinct short-lived pool. In humans, however, the life span and number of RTEs are unknown. Although (2)H(2)O labeling in young mice showed high thymic-dependent daily naïve T cell production, long term up- and down-labeling with (2)H(2)O(More)
Developing T cells express diverse antigen receptors whose specificities are not prematched to the foreign antigens they eventually encounter. Past experiments have revealed that thymocytes must productively signal in response to self antigens to mature and enter the peripheral T cell pool (positive selection), but how this process enhances effective mature(More)
Parallels between T cell kinetics in mice and men have fueled the idea that a young mouse is a good model system for a young human, and an old mouse, for an elderly human. By combining in vivo kinetic labeling using deuterated water, thymectomy experiments, analysis of T cell receptor excision circles and CD31 expression, and mathematical modeling, we have(More)
Naïve T cells continually recirculate between blood and secondary lymphoid organs, scanning dendritic cells (DC) for foreign antigen. Despite its importance for understanding how adaptive immune responses are efficiently initiated from rare precursors, a detailed quantitative analysis of this fundamental process has not been reported. Here we measure lymph(More)
Cell dynamics in subcutaneous and breast tumors can be studied through conventional imaging windows with intravital microscopy. By contrast, visualization of the formation of metastasis has been hampered by the lack of long-term imaging windows for metastasis-prone organs, such as the liver. We developed an abdominal imaging window (AIW) to visualize(More)
Metastasis, the process by which cells spread from the primary tumor to a distant site to form secondary tumors, is still not fully understood. Although histological techniques have provided important information, they give only a static image and thus compromise interpretation of this dynamic process. New advances in intravital microscopy (IVM), such as(More)
Long-term asymptomatic human immunodeficiency virus (HIV)-infected individuals (LTA) usually have low viral load and low immune activation. To discern whether viral load or immune activation is dominant in determining progression to AIDS, we studied three exceptional LTA with high viral loads. HIV type 1 isolates from these LTA were as pathogenic as viruses(More)
Although accumulating evidence indicates that chronic lymphocytic leukemia (CLL) is a disease with appreciable cell dynamics, it remains uncertain whether this also applies to patients with stable disease. In this study, (2)H(2)O was administered to a clinically homogeneous cohort of nine stable, untreated CLL patients. CLL dynamics in blood and bone marrow(More)
Forced overexpression and/or downregulation of proteins regulating epithelial-to-mesenchymal transition (EMT) has been reported to alter metastasis by changing migration and stem cell capacity of tumor cells. However, these manipulations artificially keep cells in fixed states, while in vivo cells may adapt transient and reversible states. Here, we have(More)