Allelic variation of KIR and HLA tunes the cytolytic payload and determines functional hierarchy of NK cell repertoires.

The functionality of natural killer (NK) cells is tuned during education and is associated with remodeling of the lysosomal compartment. We hypothesized that genetic variation in killer cell immunoglobulin-like receptor (KIR) and HLA, which is known to influence the functional strength of NK cells, fine-tunes the payload of effector molecules stored in secretory lysosomes. To address this possibility, we performed a high-resolution analysis of KIR and HLA class I genes in 365 blood donors and linked genotypes to granzyme B loading and functional phenotypes.

Live single cell imaging assays in glass microwells produced by laser-induced deep etching.

Miniaturization of cell culture substrates enables controlled analysis of living cells in confined micro-scale environments. This is particularly suitable for imaging individual cells over time, as they can be monitored without escaping the imaging field-of-view (FoV). Glass materials are ideal for most microscopy applications.

NK cells integrate signals over large areas when building immune synapses but require local stimuli for degranulation.

Immune synapses are large-scale, transient molecular assemblies that serve as platforms for antigen presentation to B and T cells and for target recognition by cytotoxic T cells and natural killer (NK) cells. The formation of an immune synapse is a tightly regulated, stepwise process in which the cytoskeleton, cell surface receptors, and intracellular signaling proteins rearrange into supramolecular activation clusters (SMACs). We generated artificial immune synapses (AIS) consisting of synthetic and natural ligands for the NK cell-activating receptors LFA-1 and CD16 by microcontact printing the ligands into circular-shaped SMAC structures.

A collagen-based microwell migration assay to study NK-target cell interactions.

Natural killer (NK) cell cytotoxicity in tissue is dependent on the ability of NK cells to migrate through the extracellular matrix (ECM) microenvironment. Traditional imaging studies of NK cell migration and cytotoxicity have utilized 2D surfaces, which do not properly reproduce the structural and mechanical cues that shape the migratory response of NK cells in vivo. Here, we have combined a microwell assay that allows long-term imaging and tracking of small, well-defined populations of NK cells with an interstitial ECM-like matrix.

161533 TriKE stimulates NK-cell function to overcome myeloid-derived suppressor cells in MDS.

Myelodysplastic syndrome (MDS) is a clonal heterogeneous stem cell disorder driven by multiple genetic and epigenetic alterations resulting in ineffective hematopoiesis. MDS has a high frequency of immune suppressors, including myeloid-derived suppressor cells (MDSCs), that collectively result in a poor immune response. MDSCs in MDS patients express CD155 that ligates the T-cell immunoreceptor with immunoglobulin and ITIM domain (TIGIT) and delivers an inhibitory signal to natural killer (NK) cells.

Intrinsic Functional Potential of NK-Cell Subsets Constrains Retargeting Driven by Chimeric Antigen Receptors.

Natural killer (NK) cells hold potential as a source of allogeneic cytotoxic effector cells for chimeric antigen receptor (CAR)-mediated therapies. Here, we explored the feasibility of transfecting CAR-encoding mRNA into primary NK cells and investigated how the intrinsic potential of discrete NK-cell subsets affects retargeting efficiency. After screening five second- and third-generation anti-CD19 CAR constructs with different signaling domains and spacer regions, a third-generation CAR with the CH2-domain removed was selected based on its expression and functional profiles.

[Migration of an axillary plexus catheter fragment : A severed catheter tip unnoticed on removal wandered into the central nervous system].

MIGRATION OF AN AXILLARY PLEXUS CATHETER FRAGMENT INTO THE INTRACEREBRAL COMPARTMENT: During removal of an axillary plexus catheter used for pain therapy, the catheter was probably inadvertently and unnoticed severed together with the suture fixation. The error went unnoticed and an approximately 14 cm long catheter fragment remained in the patient. The patient complained of neck pain, nausea and vomiting 2.

Microchip Screening Platform for Single Cell Assessment of NK Cell Cytotoxicity.

Here, we report a screening platform for assessment of the cytotoxic potential of individual natural killer (NK) cells within larger populations. Human primary NK 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 NK and live or dead target cells in each well could be assessed at different time points after initial mixing.

Valsalva Retinopathy: A Rare Complication After General Anesthesia.

Sudden visual loss after general anesthesia is a rare and serious complication. Unilateral visual loss can be caused by an increase in pressure in the preretinal veins with subsequent rupture and hematoma formation. Our patient most likely experienced an increase in venous pressure as a consequence of temporarily increased intrapulmonary pressures during a sustained Valsalva maneuver shortly after tracheal intubation.