During infection, Toll-like receptor agonists induce natural killer (NK)-cell activation by stimulating dendritic cells (DCs) to produce cytokines and transpresent IL-15 to NK cells. Yet the cellular dynamics underlying NK-cell activation by DCs in secondary lymphoid organs are largely unknown. Here, we have visualized NK-cell activation using mice in which NK cells and DCs express different fluorescent proteins. In response to poly I:C or lipopolysaccharide, NK cells maintained a vigorous migratory behavior, establishing multiple short contacts with maturing DCs. Furthermore, mature antigen-loaded DCs that made long-lived interactions with T cells formed short-lived contacts with NK cells. The different behaviors of T cells and NK cells during activation was correlated with distinct calcium responses upon interaction with DCs. That NK cells become activated while remaining motile may constitute an efficient strategy for sampling local concentrations of cytokines around DCs in secondary lymphoid tissues.
"While these long-lasting synapses have been observed with human cells in vitro, DCs, and NK cells establish only short interactions, usually below 3 min, in mouse lymph nodes (47). It is so far unknown, which species differences might cause these divergent interaction kinetics. "
[Show abstract][Hide abstract] ABSTRACT: Dendritic cells (DCs) and natural killer (NK) cells shape each other's functions early during immune responses. DCs activate NK cells and NK cells can mature or kill DCs. In this review we will discuss which DC and NK cell subsets are mainly affected by this interaction, where these encounters might take place and which signals are exchanged. Finally, we will point out what the clinical benefit of understanding this interaction might be and how it changed our view on NK cells as innate lymphocytes.
Frontiers in Immunology 11/2013; 4:365. DOI:10.3389/fimmu.2013.00365
"These activating domains segregate from inhibitory domains that allow MHC class I/KIR interactions and form rapidly within the first minutes of mature DC interaction with NK cells. The rapid establishment of the immunological synapse between mature DCs and resting NK cells, which ensures NK-cell activation and DC protection from NK-cell cytotoxicity at the same time, seems to be important, because in vivo imaging has revealed that DCs and NK cells might only interact with each other in T-cell areas of secondary lymphoid tissues for short periods of time with the majority of contacts being around 1min  . At these early time points, however, the synapse between DCs and NK cells is not stabilized by cytoskeletal components like actin. "
[Show abstract][Hide abstract] ABSTRACT: In both human and mouse it has been recently realized that natural killer (NK) cells do not emerge from the bone marrow with full functional competence but rather acquire functions in interaction with antigen-presenting cells (APCs), primarily dendritic cells (DCs). Here we review the mechanisms and the consequences of this NK-cell preactivation, as well as discuss new experimental models that now allow investigating these interactions for human NK cells and their response to human pathogens in vivo. These investigations will allow harnessing NK cells during vaccination for improved innate and adaptive immunity.
BioMed Research International 03/2011; 2011(3):251679. DOI:10.1155/2011/251679 · 2.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: As the PC market is poised to migrate rapidly from bulky CRTs to
thin flat panel display (FPD) monitors, a number of interface issues
must be resolved to enable and accelerate this transition. This paper
addresses a few, but major FPD interface issues, including numerous
signal wires, high clock speeds, and lack of a standard interface which
prohibits interoperability for plug-and-play
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