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. NK cell activity can be a useful marker for health screenings because impaired NK cell functions may indicate a more susceptible environment for infection or tumor development. Currently, most NK cell activity assays are focused on measuring either cytokine secretion, in particular, interferon γ (IFN-γ), or cytotoxicity against target cells such as K562, thus only providing partial information on NK cell activity. In order to develop a comprehensive test for measuring NK cell function, cytotoxicity and cytokine secretion ability should be measured simultaneously. In addition, current NK cell assays are performed by stimulating NK cells with cocktails of cytokines, antibody-coated beads, or live target cells. In this study, we developed multifunctional microparticles for NK cell activity assay (MNAs) that allow simultaneous stimulation and sensing various NK cell activities, including cytokine secretion and cytotoxicity. The surfaces of MNAs are decorated with multiple functional biomolecules, including antibodies that stimulate NK cells by engaging NK cell activating receptors, antibodies that can capture cytokines secreted by NK cells, and a peptide sensor that reacts with granzyme B, a key molecule released by NK cells for cytotoxicity. The performances of MNAs are assessed using flow cytometry and live cell imaging. NK cell activity is measured by simply mixing MNAs with NK cells and performing flow cytometry, and the results are comparable to those measured by standard NK cell activity assays.

Progressive Impairment of NK Cell Cytotoxic Degranulation Is Associated With TGF-β1 Deregulation and Disease Progression in Pancreatic Cancer

Natural killer (NK) cells are key effectors in cancer immunosurveillance and can be used as a prognostic biomarker in diverse cancers. Nonetheless, the role of NK cells in pancreatic cancer (PC) remains elusive, given conflicting data on their association with disease prognosis. In this study, using conventional K562 target cells and complementary engineered target cells providing defined and synergistic stimulation for NK cell activation, a correlation between impaired NK cell cytotoxic degranulation and PC progression was determined. Peripheral blood mononuclear cells (PBMCs) from 31 patients with newly diagnosed PC, 24 patients with non-malignant tumors, and 37 healthy controls were analyzed by flow cytometry. The frequency, phenotype, and effector functions of the NK cells were evaluated, and correlations between NK cell functions and disease stage and prognosis were analyzed. The results demonstrated that effector functions, but not frequency, of NK cells was progressively decreased on a per-cell basis during PC progression. Impaired cytotoxic degranulation, but not IFN-γ production, was associated with clinical features indicating disease progression, such as high serum CA19-9 and high-grade tumors. Significantly, this impairment correlated with cancer recurrence and mortality in a prospective analysis. Furthermore, the impaired cytotoxic degranulation was unrelated to NKG2D downregulation but was associated with increased circulating and tumor-associated TGF-β1 expression. Thus, NK cell cytotoxic activity was associated with PC progression and may be a favorable biomarker with predictive and prognostic value in PC.

Preservation of red pepper flakes using microwave-combined cold plasma treatment

BACKGROUND

Red pepper flakes are often contaminated with various microorganisms; however, any technologies aiming to decontaminate the flakes should also maintain their quality properties. This study investigated the effect of microwave-combined cold plasma treatment (MCPT) at different microwave power densities on microbial inactivation and preservation of red pepper flakes. Red pepper flake samples inoculated with spores of Bacillus cereus or Aspergillus flavus and without inoculation were subjected to MCPT at 900 W for 20 min at either low microwave power density (LMCPT, 0.17 W m^-2 ) or high microwave power density (HMCPT, 0.25 W m^-2 ).

RESULTS

The numbers of B. cereus and A. flavus spores on red pepper flakes after LMCPT and HMCPT were initially reduced by 0.7 ± 0.1 and 1.4 ± 0.3 log spores cm^-2 and by 1.5 ± 0.3 and 1.5 ± 0.2 log spores cm^-2 respectively and remained constant for 150 days at 25 °C. Immediately after HMCPT, the concentrations of capsaicin and ascorbic acid in the flakes were significantly lower than in untreated samples; however, no difference in concentration was detected during storage. Neither LMCPT nor HMCPT affected the antioxidant activity or color of the flakes during storage. LMCPT also did not affect the sensory properties and the concentrations of capsaicin and dihydrocapsaicin of the flakes, indicating its suitability in preserving their quality properties.

CONCLUSION

MCPT may provide an effective non-thermal treatment for food preservation which can improve the microbial safety and stability of red pepper flakes while maintaining intact their qualitative properties. © 2018 Society of Chemical Industry.

Ginsenoside F1 Promotes Cytotoxic Activity of NK Cells via Insulin-Like Growth Factor-1-Dependent Mechanism

Ginsenosides are the principal active components of ginseng and are considered attractive candidates for combination cancer therapy because they can kill tumors and have favorable safety profiles. However, the overall benefit of ginsenosides remains unclear, particularly in cancer immunosurveillance, considering the controversial results showing repression or promotion of immune responses. Here we identify a potentiating role of ginsenoside F1 (G-F1) in cancer surveillance by natural killer (NK) cells. Among 15 different ginsenosides, G-F1 most potently enhanced NK cell cytotoxicity in response to diverse activating receptors and cancer cells. G-F1 also improved cancer surveillance in mouse models of lymphoma clearance and metastatic melanoma that rely on NK cell activity. G-F1-treated NK cells exhibited elevated cytotoxic potential such as upregulation of cytotoxic mediators and of activation signals upon stimulation. NK cell potentiation by G-F1 was antagonized by insulin-like growth factor (IGF)-1 blockade and recapitulated by IGF-1 treatment, suggesting the involvement of IGF-1. Thus, our results suggest that G-F1 enhances NK cell function and may have chemotherapeutic potential in NK cell-based immunotherapy. We anticipate our results to be a starting point for further comprehensive studies of ginsenosides in the immune cells mediating cancer surveillance and the development of putative therapeutics.

Development of Anti-Insect Microencapsulated Polypropylene Films Using a Large Scale Film Coating System

Films containing microencapsulated cinnamon oil (CO) were developed using a large-scale production system to protect against the Indian meal moth (Plodia interpunctella). CO at concentrations of 0%, 0.8%, or 1.7% (w/w ink mixture) was microencapsulated with polyvinyl alcohol. The microencapsulated CO emulsion was mixed with ink (47% or 59%, w/w) and thinner (20% or 25%, w/w) and coated on polypropylene (PP) films. The PP film was then laminated with a low-density polyethylene (LDPE) film on the coated side. The film with microencapsulated CO at 1.7% repelled P. interpunctella most effectively. Microencapsulation did not negatively affect insect repelling activity. The release rate of cinnamaldehyde, an active repellent, was lower when CO was microencapsulated than that in the absence of microencapsulation. Thermogravimetric analysis exhibited that microencapsulation prevented the volatilization of CO. The tensile strength, percentage elongation at break, elastic modulus, and water vapor permeability of the films indicated that microencapsulation did not affect the tensile and moisture barrier properties (P > 0.05). The results of this study suggest that effective films for the prevention of Indian meal moth invasion can be produced by the microencapsulation of CO using a large-scale film production system.

PRACTICAL APPLICATION

Low-density polyethylene-laminated polypropylene films printed with ink incorporating microencapsulated cinnamon oil using a large-scale film production system effectively repelled Indian meal moth larvae. Without altering the tensile and moisture barrier properties of the film, microencapsulation resulted in the release of an active repellent for extended periods with a high thermal stability of cinnamon oil, enabling commercial film production at high temperatures. This anti-insect film system may have applications to other food-packaging films that use the same ink-printing platform.

Indian meal moth (Plodia interpunctella)-resistant food packaging film development using microencapsulated cinnamon oil

Insect-resistant laminate films containing microencapsulated cinnamon oil (CO) were developed to protect food products from the Indian meal moth (Plodia interpunctella). CO microencapsulated with polyvinyl alcohol was incorporated with a printing ink and the ink mixture was applied to a low-density polyethylene (LDPE) film as an ink coating. The coated LDPE surface was laminated with a polypropylene film. The laminate film impeded the invasion of moth larvae and repelled the larvae. The periods of time during which cinnamaldehyde level in the film remained above a minimum repelling concentration, predicted from the concentration profile, were 21, 21, and 10 d for cookies, chocolate, and caramel, respectively. Coating with microencapsulated ink did not alter the tensile or barrier properties of the laminate film. Microencapsulation effectively prevented volatilization of CO. The laminate film can be produced by modern film manufacturing lines and applied to protect food from Indian meal moth damage.

PRACTICAL APPLICATION

The LDPE-PP laminate film developed using microencapsulated cinnamon oil was effective to protect the model foods from the invasion of Indian meal moth larvae. The microencapsulated ink coating did not significantly change the tensile and barrier properties of the LDPE-PP laminate film, implying that replacement of the uncoated with coated laminate would not be an issue with current packaging equipment. The films showed the potential to be produced in commercial film production lines that usually involve high temperatures because of the improved thermal stability of cinnamon oil due to microencapsulation. The microencapsulated system may be extended to other food-packaging films for which the same ink-printing platform is used.

A kinematic analysis of relative stability of the lower extremities between subjects with and without chronic low back pain

Even though a number of studies have evaluated postural adjustments based on kinematic changes in subjects with low back pain (LBP), kinematic stability has not been examined for abnormal postural responses during the one leg standing test. The purpose of this study was to evaluate the relative kinematic stability of the lower extremities and standing duration in subjects with and without chronic LBP. In total, 54 subjects enrolled in the study, including 28 subjects without LBP and 26 subjects with LBP. The average age of the subjects was 37.8 ± 12.6 years and ranged from 19 to 63 years. The outcome measures included normalized holding duration and relative kinematic stability. All participants were asked to maintain the test position without visual input (standing on one leg with his/her eyes closed and with the contra lateral hip flexed 90°) for 25 s. The age variable was used as a covariate to control confounding effects for the data analyses. The control group demonstrated significantly longer holding duration times (T = -2.78, p = 0.007) than the LBP group (24.6 ± 4.2 s vs. 20.5 ± 6.7 s). For the relative kinematic stability, there was a difference in dominance side (F = 9.91, p = 0.003). There was a group interaction between side and lower extremities (F = 11.79, p = 0.001) as well as an interaction between age and dominance side (F = 7.91, p = 0.007). The relative kinematic stability had a moderate negative relationship with age (r = -0.60, p = 0.007) in subjects without LBP. Clinicians need to understand the effects of age and relative stability, which decreased significantly in the single leg holding test, in subjects with LBP in order to develop effective rehabilitation strategies.

Vineland social maturity scale norm examined--the Wisconsin experience with 0- to 3-year-old children

Inspection of the Vineland social Maturity Scale scores of a representative sample of 150 nonretarded children between the ages of 2 weeks and 36 months revealed that the social ages of most of these children using the original norm table were consistently higher than their chronological ages. A table of adjusted Vineland ages based on the performance of these children was provided, along with the original Vineland norms. Comparison of the original and adjusted scores suggests that the social ages on the Vineland may be overestimated in the 1- to 2-year range.