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In our previous work, a Trichinella spiralis putative serine protease (TsSP) was identified from ES products of T. spiralis intestinal infective larvae (IIL) and adult worms (AW) by immunoproteomics: it was highly expressed in IIL compared with muscle larvae (ML). In this study, the TsSP biological characteristics in larval invasion and growth were identified and its potential as a vaccine target against Trichinella infection were investigated. Expression of TsSP at various developmental phases (newborn larvae, ML, IIL, and AW) was detected by qPCR, immunofluorescent test and Western blotting. The rTsSP could specifically bind to the intestinal epithelial cell (IEC) membrane and enter into the cytoplasm. Anti-rTsSP serum suppressed the larval invasion of enterocytes in a dose-dependent mode, and killed newborn and ML of T. spiralis, decreased larval infectivity and development in the host by an ADCC-mediated mechanism. Immunization of mice with rTsSP produced a Th2 predominant immune response, and resulted in a 52.70% reduction of adult worms at 5 days post-infection (dpi) and a 52.10% reduction of muscle larvae at 42 dpi. The results revealed there was an interaction between TsSP and the host’s IEC; TsSP might be a pivotal protein for the invading, growing and parasiting of this nematode in the host. Vaccination of mice with rTsSP elicited immune protection, and TsSP is a potential target molecule for vaccines against enteral Trichinella infection.

Abiotic stresses are major environmental factors that inhibit plant growth and development impacting crop productivity. GRAS transcription factors play critical and diverse roles in plant development and abiotic stress. In this study, SlGRAS40, a member of the tomato (Solanum lycopersicum) GRAS family, was functionally characterized. In wild-type (WT) tomato, SlGRAS40 was upregulated by abiotic stress induced by treatment with D-mannitol, NaCl, or H2O2. Transgenic tomato plants overexpressing SlGRAS40 (SlGRAS40-OE) were more tolerant of drought and salt stress than WT. SlGRAS40-OE plants displayed pleiotropic phenotypes reminiscent of those resulting from altered auxin and/or gibberellin signaling. A comparison of WT and SlGRAS40-OE transcriptomes showed that the expression of a large number of genes involved in hormone signaling and stress responses were modified. Our study of SlGRAS40 protein provides evidence of how another GRAS plays roles in resisting abiotic stress and regulating auxin and gibberellin signaling during vegetative and reproductive growth in tomato.

Hesperetin (Hesp), a common flavanone glycoside, was extracted from the fruit peel of Citrus aurantium L. (Rutaceae). Hesp has been shown to possess various biological properties, including antioxidant, neuroprotective, and anti-inflammatory properties. In this study, we investigated the protective effect of Hesp on inflammatory responses in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Our results indicated that Hesp treatment dramatically suppressed secretion of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β; reduced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) gene expression; inhibited NF-κB (p65) phosphorylation; and blocked IκBα phosphorylation and degradation. Further studies revealed Hesp markedly enhanced the heme oxygenase (HO)-1 and nuclear factor erythroid 2-related factor 2 (Nrf2) expression, which were involved with inducing Nrf2 nuclear translocation and decreasing Keap1 protein expression. Together, these results indicated that the anti-inflammatory effect of Hesp may be associated with NF-κB inhibition and Nrf2/HO-1 activation.

Serine protease inhibitors (SPI) are a superfamily of the proteins able to suppress serine protease activity, and may exert the major biological function in complement activation, inflammation, and fibrinolysis. A SPI was identified from Trichinella spiralis adult worms (AW) by immunoproteomics with early infection sera. The aim of this study was to investigate the protective immune elicited by TsSPI. The complete TsSPI cDNA sequence was cloned into pQE-80 L and then expressed in Escherichia coli BL21. The rTsSPI was purified and its antigenicity was determined by Western blotting analysis. By using anti-rTsSPI serum the native TsSPI was identified in somatic and ES proteins from muscle larvae (ML). The results of qPCR and immunofluorescence assay (IFA) revealed that the expression of the TsSPI gene was observed throughout all developmental stages of T. spiralis (ML, intestinal infective larvale, 3- and 6-days AW, and newborn larvae, NBL), located principally in cuticles, stichosome, and embryos of this parasitic nematode. Vaccination of mice with rTsSPI triggered high level of anti-TsSPI IgG response, and showed a 62.2 and 57.25% worm burden reduction in the recovery of intestinal AW at 6 days post-infection (dpi) and ML at 35 dpi, respectively. The TsSPI might be a novel potential target for anti-Trichinella vaccine.

Background Limited data was available for rapid and accurate detection of COVID-19 using CT-based machine learning model. This study aimed to investigate the value of chest CT radiomics for diagnosing COVID-19 pneumonia compared with clinical model and COVID-19 reporting and data system (CO-RADS), and develop an open-source diagnostic tool with the constructed radiomics model. Methods This study enrolled 115 laboratory-confirmed COVID-19 and 435 non-COVID-19 pneumonia patients (training dataset, n = 379; validation dataset, n = 131; testing dataset, n = 40). Key radiomics features extracted from chest CT images were selected to build a radiomics signature using least absolute shrinkage and selection operator (LASSO) regression. Clinical and clinico-radiomics combined models were constructed. The combined model was further validated in the viral pneumonia cohort, and compared with performance of two radiologists using CO-RADS. The diagnostic performance was assessed by receiver operating characteristics curve (ROC) analysis, calibration curve, and decision curve analysis (DCA). Results Eight radiomics features and 5 clinical variables were selected to construct the combined radiomics model, which outperformed the clinical model in diagnosing COVID-19 pneumonia with an area under the ROC (AUC) of 0.98 and good calibration in the validation cohort. The combined model also performed better in distinguishing COVID-19 from other viral pneumonia with an AUC of 0.93 compared with 0.75 (P = 0.03) for clinical model, and 0.69 (P = 0.008) or 0.82 (P = 0.15) for two trained radiologists using CO-RADS. The sensitivity and specificity of the combined model can be achieved to 0.85 and 0.90. The DCA confirmed the clinical utility of the combined model. An easy-to-use open-source diagnostic tool was developed using the combined model. Conclusions The combined radiomics model outperformed clinical model and CO-RADS for diagnosing COVID-19 pneumonia, which can facilitate more rapid and accurate detection.

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BackgroundTrichinella spiralis is an important foodborne zoonotic parasite and it is necessary to develop a vaccine in order to interrupt transmission from animals to humans. A 31 kDa protein from T. spiralis (Ts31) is an antigen targeted by protective antibodies, and Ts31 contains a domain of trypsin-like serine protease that might have the function of serine protease. The purpose of this study was to investigate the molecular characteristics of Ts31 and its induced immune protection.MethodsExpression and localization of Ts31 in various T. spiralis phases were investigated using qPCR and immunofluorescent test (IFT). The specific binding between Ts31 and intestinal epithelium cells (IECs) was analyzed by Far-Western blotting, ELISA and IFT, and the cellular localization of binding sites was examined on confocal microscopy. The mice were subcutaneously vaccinated with recombinant Ts31 protein (rTs31), serum specific IgG was determined by ELISA, and immune protection induced by immunization with rTs31 was evaluated. Inhibition of anti-rTs31 IgG on IL1 invasion of IECs and ADCC-mediated killing of newborn larvae (NBL) was also determined.ResultsTs31 was expressed at different life-cycle stages and located principally at the stichosome and cuticle of this parasite. rTs31 was capable to specially bond to IECs, and binding site was located in the cytoplasm of IECs. Immunization of mice with rTs31 elicited a significant humoral response and protection, as demonstrated by a 56.93% reduction of adult worms at 6 days post-infection (dpi) and a 53.50% reduction of muscle larvae at 42 dpi after larval challenge. Anti-rTs31 antibodies impeded T. spiralis penetration of enterocytes in a dose-dependent pattern, and participated in the destruction of NBL by an ADCC-mediated manner.ConclusionsTs31 facilitated the T. spiralis penetration of intestinal epithelium, which could make it a vaccine candidate target molecule against Trichinella infection.