Search

Like all coronaviruses, infectious bronchitis virus, the causative agent of infectious bronchitis in chickens, exhibits a high mutation rate. Adaptive mutations that arise during the production of live attenuated vaccines against IBV often decrease virulence. The specific impact of these mutations on viral pathogenicity, however, has not been fully elucidated. In this study, we identified a mutation at the 3' end of the S gene in an IBV strain that was serially passaged in chicken embryos, and showed that this mutation resulted in a 9-aa truncation of the cytoplasmic tail (CT) of the S protein. This phenomenon of CT truncation has previously been observed in the production of attenuated vaccines against other coronaviruses such as the porcine epidemic diarrhea virus. We next discovered that the 9-aa truncation in the S protein CT resulted in the loss of the endoplasmic-reticulum-retention signal (KKSV). Rescue experiments with recombinant viruses confirmed that the deletion of the KKSV motif impaired the localization of the S protein to the endoplasmic-reticulum-Golgi intermediate compartment (ERGIC) and increased its expression on the cell surface. This significantly reduced the incorporation of the S protein into viral particles, impaired early subgenomic RNA and protein synthesis, and ultimately reduced viral invasion efficiency in CEK cells. In vivo experiments in chickens confirmed the reduced pathogenicity of the mutant IBV strains. Additionally, we showed that the adaptive mutation altered the TRS-B of ORF3 and impacted the transcriptional regulation of this gene. Our findings underscore the significance of this adaptive mutation in the attenuation of IBV infection and provide a novel strategy for the development of live attenuated IBV vaccines. Author summary: The administration of live attenuated vaccines is currently recognized as the most effective strategy for preventing infections caused by IBV. Understanding how mutations arising during vaccine production influence IBV virulence is crucial for developing more effective vaccines. In this study, we focused on a specific mutation in the S gene of IBV, which arose during viral propagation in chicken embryos. This mutation resulted in the truncation of the CT region of the S protein and concurrently eliminated a critical motif required for the retention of the protein at the viral assembly site. Similar S protein truncation has been observed in the production of attenuated vaccines against other coronaviruses, suggesting that the mutation identified in IBV in the present study was an adaptive mutation driven by natural selection pressure. Our findings underscore the value of targeting this adaptive mutation site as a strategy for reducing IBV virulence, and for the development of effective live attenuated vaccines against IBV and other coronaviruses. [ABSTRACT FROM AUTHOR]

Background Psoriasis is a common chronic inflammatory disease with an unclear aetiology. Keratinocytes in psoriasis are susceptible to exogenous triggers that induce inflammatory cell death. Objectives To investigate whether gasdermin E (GSDME)-mediated pyroptosis in keratinocytes contributes to the pathogenesis of psoriasis. Methods Skin samples from patients with psoriasis and from healthy controls were collected to evaluate the expression of GSDME, cleaved caspase-3 and inflammatory factors. We then analysed the data series GSE41662 to further compare the expression of GSDME between lesional and nonlesional skin samples in those with psoriasis. In vivo, a caspase-3 inhibitor and GSDME-deficient mice (Gsdme–/–) were used to block caspase-3/GSDME activation in an imiquimod-induced psoriasis model. Skin inflammation, disease severity and pyroptosis-related proteins were analysed. In vitro , tumour necrosis factor (TNF)-α-induced caspase-3/GSDME-mediated pyroptosis in the HACAT cell line was explored. Results Our analysis of the GSE41662 data series found that GSDME was upregulated in psoriasis lesions vs. normal skin. High levels of inflammatory cytokines such as interleukin (IL)-1β, IL-6 and TNF-α were also found in psoriasis lesions. In mice in the Gsdme –/– and caspase-3 inhibitor groups, the severity of skin inflammation was attenuated and GSDME and cleaved caspase-3 levels decreased after imiquimod treatment. Similarly, IL-1β, IL-6 and TNF-α expression was decreased in the Gsdme –/– and caspase-3 inhibitor groups. In vitro , TNF-α induced HACAT cell pyroptosis through caspase-3/GSDME pathway activation, which was suppressed by blocking caspase-3 or silencing Gsdme. Conclusions Our study provides a novel explanation of TNF-α/caspase-3/GSDME-mediated keratinocyte pyroptosis in the initiation and -acceleration of skin inflammation and the progression of psoriasis. [ABSTRACT FROM AUTHOR]

This paper presents detailed qualitative evidence from a case study of teachers in five Chinese schools in one city. It explicitly seeks to show how developments in government policy towards education have altered the management of teacher labour inside schools as well as the teacher labour process as expressed by the teachers themselves in interviews and questionnaires. In this paper, we explore supervision, work intensification, and the erosion of professionalism. We conclude that some changes have taken place as predicted by the labour process model, but that the reaction of the teachers to more extensive controls has been variable. In particular senior school managers did have greater control with high levels of supervision, but that was generally welcomed as preferable to the previous system of outside control and neglect. While workload increased overall, the teachers were more likely to have to work outside of normal duties rather than experience any increase in formal contractual obligations.

In this present study, we developed a reliable and simple ultra‐performance liquid chromatography tandem mass spectrometry (UPLC–MS/MS) assay for the simultaneous quantification of paeoniflorin, albiflorin, oxypaeoniflorin, benzoylpaeoniflorin and isomaltopaeoniflorin in beagle dog plasma. We also analyzed the pharmacokinetics of those components after oral administration of fried Radix Paeoniae Alba (FRPA) in beagle dogs. Plasma samples were processed by protein precipitation with methanol. Chromatographic separation was performed with a Waters HSS‐T3 C18 column (100 × 2.1 mm, 1.8 μm, kept at 40°C) using multiple reaction monitoring mode. A gradient elution procedure was used with solvent A (0.02% formic acid–water) and solvent B (0.02% formic acid–acetonitrile) as mobile phases. Method validation was performed as US Food and Drug Administration guidelines, and the results met the acceptance criteria. The method we establish in this experiment was successfully applied to the pharmacokinetic study after oral administration of FRPA extract to beagle dogs. [ABSTRACT FROM AUTHOR]