BackgroundRecently, we found that Staphylococcus aureus produces extracellular vesicles (EV) that contain pathogenic proteins. Although S. aureus infection has been linked with atopic dermatitis (AD), the identities of the causative agents from S. aureus are controversial. We evaluated whether S. aureus-derived EV are causally related to the pathogenesis of AD.MethodsExtracellular vesicles were isolated by the ultracentrifugation of S. aureus culture media. The EV were applied three times per week to tape-stripped mouse skin. Inflammation and immune dysfunction were evaluated 48 h after the final application in hairless mice. Extracellular vesicles-specific IgE levels were measured by ELISA in AD patients and healthy subjects.ResultsThe in vitro application of S. aureus EV increased the production of pro-inflammatory mediators (IL-6, thymic stromal lymphopoietin, macrophage inflammatory protein-1α, and eotaxin) by dermal fibroblasts. The in vivo application of S. aureus EV after tape stripping caused epidermal thickening with infiltration of the dermis by mast cells and eosinophils in mice. These changes were associated with the enhanced cutaneous production of IL-4, IL-5, IFN-γ, and IL-17. Interestingly, the serum levels of S. aureus EV-specific IgE were significantly increased in AD patients relative to healthy subjects.ConclusionThese results indicate that S. aureus EV induce AD-like inflammation in the skin and that S. aureus-derived EV are a novel diagnostic and therapeutic target for the control of AD.

Protein-protein interactions (PPIs) trigger a wide range of biological signaling pathways that are crucial for biomedical research and drug discovery. Various techniques have been used to study specific proteins, including affinity chromatography, activity-based probes, affinity-based probes and photo-affinity labeling (PAL). PAL has become one of the most powerful strategies to study PPIs. Traditional photocrosslinkers are used in PAL, including benzophenone, aryl azide, and diazirine. Upon photoirradiation, these photocrosslinkers (Pls) generate highly reactive species that react with adjacent molecules, resulting in a direct covalent modification. This review introduces recent examples of chemical proteomics study using PAL for PPIs.

The emergence of multidrug-resistant Klebsiella pneumoniae highlights the need to develop preventive measures to ameliorate Klebsiella infections. Bacteria-derived extracellular vesicles (EVs) are spherical nanometer-sized proteolipids enriched with outer membrane proteins. Gram-negative bacteria-derived EVs have gained interest for use as nonliving complex vaccines. In the present study, we evaluated whether K. pneumoniae-derived EVs confer protection against bacteria-induced lethality. K. pneumoniae-derived EVs isolated from in vitro bacterial culture supernatants induced innate immunity, including the upregulation of co-stimulatory molecule expression and proinflammatory mediator production. EV vaccination via the intraperitoneal route elicited EV-reactive antibodies and interferon-gamma-producing T-cell responses. Three vaccinations with the EVs prevented bacteria-induced lethality. As verified by sera and splenocytes adoptive transfer, the protective effect of EV vaccination was dependent on both humoral and cellular immunity. Taken together, these findings suggest that K. pneumoniae-derived EVs are a novel vaccine candidate against K. pneumoniae infections.

Eosinophils play proinflammatory roles in helminth infections and allergic diseases. Under steady-state conditions, eosinophils are abundantly found in the small intestinal lamina propria, but their physiological function is largely unexplored. In this study, we found that small intestinal eosinophils down-regulate Th17 cells. Th17 cells in the small intestine were markedly increased in the ΔdblGATA-1 mice lacking eosinophils, and an inverse correlation was observed between the number of eosinophils and that of Th17 cells in the small intestine of wild-type mice. In addition, small intestinal eosinophils suppressed the in vitro differentiation of Th17 cells, as well as IL-17 production by small intestinal CD4+ T cells. Unlike other small intestinal immune cells or circulating eosinophils, we found that small intestinal eosinophils have a unique ability to constitutively secrete high levels of IL-1 receptor antagonist (IL-1Ra), a natural inhibitor of IL-1β. Moreover, small intestinal eosinophils isolated from IL-1Ra−deficient mice failed to suppress Th17 cells. Collectively, our results demonstrate that small intestinal eosinophils play a pivotal role in the maintenance of intestinal homeostasis by regulating Th17 cells via production of IL-1Ra.

Summary Plants have recently received a great deal of attention as a means of producing recombinant proteins. Despite this, a limited number of recombinant proteins are currently on the market and, if plants are to be more widely used, a cost‐effective and efficient purification method is urgently needed. Although affinity tags are convenient tools for protein purification, the presence of a tag on the recombinant protein is undesirable for many applications. A cost‐effective method of purification using an affinity tag and the removal of the tag after purification has been developed. The family 3 cellulose‐binding domain ( CBM 3), which binds to microcrystalline cellulose, served as the affinity tag and the small ubiquitin‐related modifier ( SUMO ) and SUMO ‐specific protease were used to remove it. This method, together with size‐exclusion chromatography, enabled purification of human interleukin‐6 ( hIL 6) with a yield of 18.49 mg/kg fresh weight from leaf extracts of Nicotiana benthamiana following Agrobacterium ‐mediated transient expression. Plant‐produced hIL 6 (P‐ hIL 6) contained less than 0.2 EU/μg (0.02 ng/mL) endotoxin. P‐ hIL 6 activated the Janus kinase‐signal transducer and activator of transcriptional pathways in human LNC aP cells, and induced expression of IL ‐21 in activated mouse CD 4 + T cells. This approach is thus a powerful method for producing recombinant proteins in plants.

Recent technological advances have expanded fluorescence (FL) imaging into the second near-infrared region (NIR-II; wavelength = 1000-1700 nm), providing high spatial resolution through deep tissues. However, bright and compact fluorophores are rare in this region, and sophisticated control over NIR-II probes has not been fully achieved yet. Herein, we report an enzyme-activatable NIR-II probe that exhibits FL upon matrix metalloprotease activity in tumor microenvironment. Bright and stable PbS/CdS/ZnS core/shell/shell quantum dots (QDs) were synthesized as a model NIR-II fluorophore, and activatable modulators were attached to exploit photoexcited electron transfer (PET) quenching. The quasi type-II QD band alignment allowed rapid and effective FL modulations with the compact surface ligand modulator that contains methylene blue PET quencher. The modulator was optimized to afford full enzyme accessibility and high activation signal surge upon the enzyme activity. Using a colon cancer mouse model, the probe demonstrated selective FL activation at tumor sites with 3-fold signal enhancement in 10 min. Optical phantom experiments confirmed the advantages of the NIR-II probe over conventional dyes in the first near-infrared region.

A fundamental assumption in this paper is that user satisfaction depends on product design. The approach consists of 5 steps: (1) define user satisfaction, (2) decompose product design elements, (3) conduct experiments, (4) develop relationship models, and (5) analyse critical design features. In order to demonstrate the practicability of this approach, relationship models were developed based on experimental data using a total of 60 subjects (30 American and 30 Korean subjects). In addition, critical design features and their common properties were identified for audio/visual consumer products. Similarities and differences between American and Korean consumers were discussed. The resulting relationship models can be used to predict user satisfaction and provide significant remedies for design change.

Recently, many nanomedical studies have been focused on magnetic nanoparticles (MNPs) because MNPs possess attractive properties for potential uses in imaging, drug delivery, and theranostics. MNPs must have optimized size as well as functionalized surface for such applications. However, careful cytotoxicity and genotoxicity assessments to ensure the biocompatibility and biosafety of MNPs are essential. In this study, Fe3O4 MNPs of different sizes (approximately 10 and 100–150 nm) were prepared with different functional groups, hydroxyl (–OH) and amine (–NH2) groups, by coating their surfaces with tetraethyl orthosilicate (TEOS), 3-aminopropyltrimethoxysilane (APTMS) or TEOS/APTMS. Differential cellular responses to those surface-functionalized MNPs were investigated in normal fibroblasts vs. fibrosarcoma cells. Following the characterization of MNP properties according to size, surface charge and functional groups, cellular responses to MNPs in normal fibroblasts and fibrosarcoma cells were determined by quantifying metabolic activity, membrane integrity, and DNA stability. While all MNPs induced just about 5% or less cytotoxicity and genotoxicity in fibrosarcoma cells at lower than 500 μg/mL, APTMS-coated MNPs resulted in greater than 10% toxicity against normal cells. Particularly, the genotoxicity of MNPs was dependent on their dose, size and surface charge, showing that positively charged (APTMS- or TEOS/APTMS-coated) MNPs induced appreciable DNA aberrations irrespective of cell type. Resultantly, smaller and positively charged (APTMS-coated) MNPs led to more severe toxicity in normal cells than their cancer counterparts. Although it was difficult to fully differentiate cellular responses to various MNPs between normal fibroblasts and their cancer counterparts, normal cells were shown to be more vulnerable to internalized MNPs than cancer cells. Our results suggest that functional groups and sizes of MNPs are critical determinants of degrees of cytotoxicity and genotoxicity, and potential mechanisms of toxicity.