Expansion of cytotoxic natural killer cells in multiple myeloma patients using K562 cells expressing OX40 ligand and membrane-bound IL-18 and IL-21.

Background: Natural killer (NK) cell-based immunotherapy is a promising treatment approach for multiple myeloma (MM), but obtaining a sufficient number of activated NK cells remains challenging. Here, we report an improved method to generate ex vivo expanded NK (eNK) cells from MM patients based on genetic engineering of K562 cells to express OX40 ligand and membrane-bound (mb) IL-18 and IL-21.

Methods: K562-OX40L-mbIL-18/-21 cells were generated by transducing K562-OX40L cells with a lentiviral vector encoding mbIL-18 and mbIL-21, and these were used as feeder cells to expand NK cells from peripheral blood mononuclear cells of healthy donors (HDs) and MM patients in the presence of IL-2/IL-15.

Multifunctional Microparticles with Stimulation and Sensing Capabilities for Facile NK Cell Activity Assay.

Natural killer (NK) cells are a subset of innate lymphoid cells playing an important role in immune surveillance and early defense against infection and cancer. They recognize and directly kill infected or transformed cells. At the same time, they produce various cytokines and chemokines to regulate other immune cells.

Expansion of Human NK Cells Using K562 Cells Expressing OX40 Ligand and Short Exposure to IL-21.

Natural Killer (NK) cell-based immunotherapy used to treat cancer requires the adoptive transfer of a large number of activated NK cells. Here, we report a new effective method to expand human NK cells using K562 cells genetically engineered (GE) to express OX40 ligand (K562-OX40L) in combination with a short exposure to soluble IL-21. In addition, we describe a possible mechanism of the NK cell expansion through the OX40 receptor-OX40 ligand axis which is dependent on NK cell homotypic interaction.

X-ray as Irradiation Alternative for K562 Feeder Cell Inactivation in Human Natural Killer Cell Expansion.

Background/aim: γ-Irradiation has been proven to be the most effective method to inactivate K562 cells, but γ-irradiators are not available in some institutes. This study was designed to compare the effects of X-ray and γ-irradiation on K562 cells in natural killer (NK) cell expansion.

Materials And Methods: To expand NK cells, isolated peripheral blood mononuclear cells (PBMCs) were co-cultured with γ-irradiated or X-ray-treated K562 cells plus IL-2 and IL-15.

Pt-Decorated Magnetic Nanozymes for Facile and Sensitive Point-of-Care Bioassay.

Development of facile and sensitive bioassays is important for many point-of-care applications. In this study, we fulfilled such demand by synthesizing Pt-decorated magnetic nanozymes and developing a bioassay based on unique properties of the newly synthesized nanozymes. FeO-Pt/core-shell nanoparticles (MPt/CS NPs) with various compositions were synthesized and characterized.

Dynamic Micropatterning of Cells on Nanostructured Surfaces Using a Cell-friendly Photoresist.

Cellular dynamics under complex topographical microenvironments are important for many biological processes in development and diseases, but systematic investigation has been limited due to the lack of technology. Herein, we developed a new dynamic cell patterning method based on a cell-friendly photoresist polymer that allows in situ control of cell dynamics on nanostructured surfaces. Using this method, we quantitatively compared the spreading dynamics of cells on nanostructured surfaces to those on flat surfaces.

Simple and Sensitive Point-of-Care Bioassay System Based on Hierarchically Structured Enzyme-Mimetic Nanoparticles.

An enzyme-mimetic nanoparticle-based point of care bioassay device is developed for rapid and sensitive detection of analytes. Digital images acquired by smart cellular phones allow quantifying the amounts of analytes. Using this new device, quantitative analysis of liquid sample is performed within 15 min with an order of magnitude enhancement of sensitivity compared with conventional Au nanoparticle-based devices.