Genetic control of chicken heterophil function in advanced intercross lines: associations with novel and with known <Emphasis Type="Italic">Salmonella</Emphasis> resistance loci and a likely mechanism for cell death in extracellular trap production

Heterophils, the avian polymorphonuclear leukocyte and the counterpart of mammalian neutrophils, generate the primary innate response to pathogens in chickens. Heterophil performance against pathogens is associated with host disease resistance, and heterophil gene expression and function are under genetic control. To characterize the genomic basis of heterophil function, heterophils from F₁₃ advanced intercross chicken lines (broiler × Leghorn and broiler × Fayoumi) were assayed for phagocytosis and killing of Salmonella enteritidis, oxidative burst, and extracellular trap production. A whole-genome association analysis of single nucleotide polymorphisms at 57,636 loci identified genomic locations controlling these functional phenotypes. Genomic analysis revealed a significant association of extracellular trap production with the SAL1 locus and the SLC11A1 gene, which have both been previously associated with resistance to S. enteritidis. Fine mapping supports SIVA1 as a candidate gene controlling SAL1-mediated resistance and indicates that the proposed cell-death mechanism associated with extracellular trap production, ETosis, likely functions through the CD27/Siva-1-mediated apoptotic pathway. The SLC11A1 gene was also associated with phagocytosis of S. enteritidis, suggesting that the Slc11a1 protein may play an additional role in immune response beyond depleting metal ions to inhibit intracellular bacterial growth. A region of chromosome 6 with no characterized genes was also associated with extracellular trap production. Further characterization of these novel genes in chickens and other species is needed to understand their role in polymorphonuclear leukocyte function and host resistance to disease.     

Three-dimensional cell culture systems as an in vitro platform for cancer and stem cell modeling

Three-dimensional(3 D) culture systems are becoming increasingly popular due to their ability to mimic tissue-like structures more effectively than the monolayer cultures. In cancer and stem cell research, the natural cell characteristics and architectures are closely mimicked by the 3 D cell models. Thus, the 3 D cell cultures are promising and suitable systems for various proposes, ranging from disease modeling to drug target identification as well as potential therapeutic substances that may transform our lives. This review provides a comprehensive compendium of recent advancements in culturing cells, in particular cancer and stem cells, using 3 D culture techniques. The major approaches highlighted here include cell spheroids, hydrogel embedding, bioreactors, scaffolds, and bioprinting. In addition, the progress of employing 3 D cell culture systems as a platform for cancer and stem cell research was addressed, and the prominent studies of 3 D cell culture systems were discussed.     

Preferential pattern of mouse neutrophil cell death in response to various stimulants

Neutrophils undergo cell death processes once their physiological function has been fulfilled. Apoptosis, necrosis, pyroptosis, or NETosis, a unique form of cell death, could occur, depending on the type of stimulant or inhibitory intervention. We investigated whether phorbol myristate acetate (PMA) and Klebsiella pneumoniae (KP), serving as stimulants, or whether an inhibitor (cytochalasin B, CytB) could alter the morphology and gene expression pattern associated with mouse neutrophil cell death. Fluorescence microscopy, flow cytometry, and real-time PCR approaches were used to identify morphological changes, percentages of cell death, and gene expression patterns, respectively. The results showed an increase in the percentage of cell death in PMA and KP groups, whereas CytB exerted inhibitory effects. Fluorescently stained cell nuclei revealed significantly different percentages of cell death among treatments. Moreover, there was a stepwise increase in cell death from 90 to 150 min after stimulation. Quantification of the release of neutrophil extracellular traps (NETs) demonstrated clearly elevated amounts in cells stimulated with KP, while the amount of NETs was slightly increased or unchanged with PMA or CytB treatments. Analysis of the genes involved in cell death revealed that mRNA expression of CASP1, IL1β, IL18, MCL1, NLRP3, and PYCARD was down-regulated in the PMA group, with the exception of AIM2 and CASP3. The expression of AIM2, IL1β, MCL1, and NLRP3 was up-regulated in KP-stimulated neutrophils, while CASP1, CASP3, IL18, and PYCARD genes were down-regulated. In summary, a spectrum of specific cell stimulants and exposure durations accounted for different outcomes in mouse neutrophil cell death.     

Fabrication of 3D calcium-alginate scaffolds for human glioblastoma modeling and anticancer drug response evaluation

The three-dimensional (3D) cell culture model has been increasingly used to study cancer biology and screen for anticancer agents due to its close mimicry to in vivo tumor biopsies. In this study, 3D calcium(Ca)-alginate scaffolds were developed for human glioblastoma cell culture and an investigation of the responses to two anticancer agents, doxorubicin and cordycepin. Compared to the 2D monolayer culture, glioblastoma cells cultured on these 3D Ca-alginate scaffolds showed reduced cell proliferation, increased tumor spheroid formation, enhanced expression of cancer stem cell genes (CD133, SOX2, Nestin, and Musashi-1), and improved expression of differentiation potential-associated genes (GFAP and β-tubulin III). Additionally, the vascularization potential of the 3D glioblastoma cells was increased, as indicated by a higher expression of tumor angiogenesis biomarker (VEGF) than in the cells in 2D culture. To highlight the application of Ca-alginate scaffolds, the 3D glioblastomas were treated with anticancer agents, including doxorubicin and cordycepin. The results demonstrated that the 3D glioblastomas presented a greater resistance to the tested anticancer agents than that of the cells in 2D culture. In summary, the 3D Ca-alginate scaffolds for glioblastoma cells that were developed in this study offer a promising platform for anticancer agent screening and the discovery of drug-resistant mechanisms of cancer.     

Effects of mummy consumption on fitness and oviposition site selection on Harmonia axyridis

Intraguild predation (IGP) has been commonly reported between predators and parasitoids used as biological control agents as predators consuming parasitoids within their hosts. However, the effect of parasitoid–mummy consumption on the fitness of the predator and subsequent oviposition site selection have not been well studied. In our study, we conducted two laboratory experiments to examine the influence of Aphidius gifuensis Ashmead (Hymenoptera: Braconidae) mummies as prey on fitness and subsequently oviposition site selection of Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae). Results indicate that when H. axyridis was reared on A. gifuensis mummies only, its larval development was prolonged, and body weight of the 4th instar larvae and newly emerged adults, and fecundity decreased. Moreover, H. axyridis did not exhibit oviposition preference on plants infested with unparasitized aphids or aphids parasitized for shorter than 9 days. However, compared with plants with mummies (parasitized ≥9 days), H. axyridis laid more eggs on plants with unparasitized aphids. In contrast, H. axyridis previously fed with A. gifuensis mummies did not show a significant oviposition preference between plants with unparasitized aphids and those with mummies (parasitized ≥9 days). Overall, our results suggest that mummy consumption reduced the fitness of H. axyridis. Although H. axyridis avoided laying eggs on plants with A. gifuensis mummies, prior feeding experience on A. gifuensis mummies could alter the oviposition site preference. Thus, in biological control practice, prior feeding experience of H. axyridis should be carefully considered for reduction of IGP and increase of fitness of H. axyridis on A. gifuensis.     

Enhancement of cordycepin production from Cordyceps militaris culture by epigenetic modification

Biotechnology Letters - Cordycepin (3′-deoxyadenosine) is a nucleoside analogue and biosynthesised by Cordyceps militaris, an entomopathogenic fungus. In this study, an epigenetic modifier...