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•PS could improve the immunosuppressive effects caused by CTX on silkworm.•PS exhibited antioxidant activity by increasing the SOD, CAT, GSH-Px and decreasing ROS level.•PS could ...regulate the immunity of silkworm by reprogramming of lipid and amino acid metabolisms.
The present study investigated the immune regulatory mechanisms of Poria cocos polysaccharides (PS) in a cyclophosphamide (CTX)-induced immunosuppression silkworm model. We found that PS increased the superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities, as well as reactive oxygen species (ROS) levels in the fat body or haemocytes of CTX-treated silkworms. PS also strongly stimulated the immunity of silkworms by increasing haemocyte counts and PO activity and upregulating the mRNA expression of immune-related genes. We further investigated the metabolic profile of the fat body after PS treatment using liquid chromatography–massspectrometry/mass spectrometry (LC–MS/MS) and identified 236 differentially expressed metabolites. Among them, nine metabolites related to amino acid metabolism were present at high levels in the PS-treated group, whereas the contents of metabolites involved in sphingolipid metabolism and alpha-linolenic acid metabolism were significantly decreased after PS treatment. The amino acid metabolism pathways and lipid metabolism pathways were found to be significantly altered in the PS-treated group, which indicates that PS may regulate the immune system of silkworms by reprogramming lipid and amino acid metabolism. This study provides new insight into the immune regulatory effect of PS in animals.
Poria cocos
polysaccharides (PS) have been used as Chinese traditional medicine with various pharmacological effects, including antiviral, anti-oxidative, and immunomodulatory activities. Herein
...Bombyx mori
silkworm was used as a model animal to evaluate the immunomodulatory effects of PS
via
detecting the changes of innate immune parameters and explore the underlying molecular mechanism of the immunoregulatory effect of PS using Illumina HiSeq Xten platform. The results presented here demonstrated that a hemocoel injection of PS significantly enhanced the cellular immunity of silkworm, including hemocyte phagocytosis, microaggregation, and spreading ability. A total of 335 differentially expressed genes (DEGs) were screened, including 214 upregulated genes and 121 downregulated genes by differential expression analysis. Gene annotation and enrichment analyses showed that many DEGs related to immune signal recognition, detoxification, proPO activation, carbohydrate metabolism, and lipid metabolism were significantly upregulated in the treatment group. The Kyoto Encyclopedia of Genes and Genomes-based Gene Set Enrichment Analysis also revealed that the more highly expressed gene sets in the PS treatment silkworm were mainly related to immune signal transduction pathways and energy metabolism. In addition, the activity of four enzymes related to immunity and energy metabolism—including phenoloxidase, glucose-6-phosphate dehydrogenase, hexokinase, and fatty acid synthetase—were all significantly increased in the larvae injected with PS. We performed qRT-PCR to examine the expression profile of immune and metabolic-related genes, which further verified the reliability of our transcriptome data and suggested that PS can regulate the immunity of silkworm by enhancing the cellular immunity and modulating the expression levels of genes related to immune responses and physiological metabolism. These findings will lay a scientific foundation for the use of PS as an immunomodulator in disease prevention in human beings or animals.
The present study explored the ability of a novel spent chrysanthemum adsorbent prepared from acid acetaldehyde for the removal of Cu2+ from an aqueous solution. The effect of various parameters, ...including solution pH, adsorbent dosage, contact time and temperature on adsorption of Cu2+ were studied by batch experiments. According to the experimental results, the optimal pH range and optimum dosage were found to be 3.0–5.0 and 6.0g/L, respectively. The adsorption amount at equilibrium decreased with the increase of temperature. Freudlich model provided better correlation for the adsorption of Cu2+ by modified spent Chrysanthemum (MSC) (R=0.99)and spent Chrysanthemum (SC)(R=0.98). Adsorption capacity of MSC was 692mg/g at 293K, but it was 400mg/g at 293K for SC. The adsorption process on Cu2+ proceeded rapidly and almost reached adsorption equilibrium within 20min. The kinetics data of MSC were analyzed using the pseudo-first-order equations and pseudo-second-order equations. The pseudo-second-order equation fitted the experimental data very well (R=0.99). The adsorption amount at equilibrium decreased with the increase of temperature. The thermodynamic parameters showed that the biosorption was exothermic and spontaneous. Experimental results showed that MSC could be used as an effective biosorbent for Cu2+ removal from aqueous solutions.
•Two transcriptomes were generated from the hemocytes of the PBS- and Bt-injected B. mori larvae.•We identified 217 DEGs between the PBS and Bt-injected groups, of which 133 genes were upregulated ...and 84 genes were downregulated.•The qRT-PCR results showed significant identical expression tendency as the deep sequencing data.•A large number of immune-related genes of the hemocyte in silkworm were found after exposure to Bt by RNA-seq.
In this study, we describe RNA-seq expression profiling of larval Bombyx mori response to hemocoel injection of Bacillus thuringiensis (Bt). Two transcriptomes were generated from the hemocytes of the PBS- and Bt-injected B. mori larvae. More than 49 million 100-bp paired-end reads, encompassing over 7.3 Gb of sequence data, were generated for each library. After filtering the raw reads and removing the rRNA mapped reads, more than 89% of the reads in each library could be mapped to the silkworm genome reference sequence. Comparison of gene expression levels revealed that a total of 133 unigenes were upregulated while 84 unigenes were downregulated in PBS vs Bt. To further investigate the biological functions of different expression genes (DEGs), gene ontology (GO) and functional enrichment analysis were performed to map all the DEGs to terms in the GO, euKaryotic Ortholog Groups of proteins (KOG) and Kyoto Encyclopedia of Genes and Genomes Pathway (KEGG) database. Among these DEGs, many genes involved in immunity against Bt challenge were identified. These included genes participated in pattern recognition, antimicrobial peptides, insecticide resistance or detoxification, immune melanization, cytoskeleton reorganization and many other immune effectors. To confirm the gene expression patterns identified by the RNA-seq data, the transcript levels of 10 immune related DEGs were examined by quantitative real-time PCR (qRT-PCR). The results showed that the DEGs obtained from the deep sequencing data were accurate and gene expression profiles from RNA-Seq data were reliable. Our studies provide insights into the to immune response of B. mori underling the stress of Bt, which is valuable to understand how Bt affects the innate immune system of silkworm and provide new approaches to control insect pests by using Bt as a biological insecticide.
In this work, we analyzed the effects of chromium (Cr) and lead (Pb) on immune and antioxidant systems of Galleria mellonella. In particular, after exposure to diets containing environmentally ...relevant concentrations (5, 50 and 100μg/g) of Cr or Pb for 7d, alterations in innate immune parameters and the activity of endogenous enzymes were measured in larvae. The results showed that 1) compared with the control, the lowest doses (5μg/g) of Cr and Pb significantly increased the levels of innate immune parameters (total hemocyte count, THC; phagocytic activity; extent of encapsulation) of the larvae and hemolymph immune enzyme activities (acid phosphatase, ACP; alkaline phosphatase, AKP; phenoloxidase, PO), whereas the highest doses (100μg/g) of Cr and Pb inhibited them; 2) the activity of antioxidant enzymes (superoxide dismutase, SOD; peroxidase, POD; catalase, CAT) showed significant increases with increasing concentrations of dietary Cr and Pb, and were significantly higher than those of the control; and 3) feeding the larvae with experimental concentrations of either Cr or Pb resulted similar patterns of changes of all the parameters examined. The current study suggested that moderate amounts of Cr and Pb enhance the innate immunity of G. mellonella, but that large amounts led to the inhibition of larval immune function, and also indicated that the experimental concentrations of Cr and Pb used caused strong oxidative stresses in the larvae.
Abstract
The bacterium
Photorhabdus luminescens
produces a number of insecticidal proteins to kill its larval prey. In this study, we cloned the gene coding for a binary toxin PirA
1
B
1
and purified ...the recombinant protein using affinity chromatography combined with desalination technology. Furthermore, the cytotoxicity of the recombinant protein against the haemocytes of
Galleria mellonella
larvae was investigated. We found that the protein had haemocoel insecticidal activity against
G. mellonella
with an LD50 of 131.5 ng/larva. Intrahaemocoelic injection of PirA
1
B
1
into
G. mellonella
resulted in significant decreases in haemocyte number and phagocytic ability. In
in vitro
experiments, PirA
1
B
1
inhibited the spreading behaviour of the haemocytes of
G. mellonella
larvae and even caused haemocyte degeneration. Fluorescence microscope analysis and visualization of haemocyte F-actin stained with phalloidin-FITC showed that the PirA
1
B
1
toxin disrupted the organization of the haemocyte cytoskeleton. Our results demonstrated that the PirA
1
B
1
toxin disarmed the insect cellular immune system.
In this study, the removal of Cr(VI) from aqueous solutions by modified Litchi peel (MLP) has been investigated. Fourier-transform infrared spectrophotometer (FTIR) and scanning electron microscopic ...analysis (SEM) were used to characterize the biosorbents. The main results are as follow: 1) the optimal pH condition and optimum dosage for the adsorption of Cr(VI) were found to be 1–4 and 8.0gL−1, respectively; 2) the adsorption process on Cr(VI) increased rapidly in 80min and almost reached adsorption equilibrium in 100min; 3) the adsorption of Cr(VI) increased with the increase of temperature. Furthermore, the Langmuir and Freudlich models were used to study the equilibrium process. It was found that the Langmuir model provided better correlation for the adsorption of Cr(VI) on MLP and Litchi peel (LP). The maximum adsorption at equilibrium for MLP is 9.55mgg−1 at 303K, while for LP it is only 7.05mgg−1 at 303K. Different kinetic models were used to analyze the kinetics of the adsorption. The pseudo-second-order model could better reflect the MLP adsorption kinetic process of Cr(VI). The thermodynamic parameters showed that the biosorption was endothermic, and there was an energy barrier for the adsorption of Cr(VI) on MLP. The present study demonstrated that MLP is an effective adsorbent for removing Cr(VI) from aqueous solutions.
•Utilization of modified Litchi peel (MLP) as a cheap and effective sorbent for the removal of Cr(VI).•The adsorption process on Cr(VI) increased in 80min and almost reached adsorption equilibrium.•The adsorption amount at equilibrium increased with the increase of temperature.•The biosorption was endothermic.•The pseudo-second-order equation fitted the experimental data very well.
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•Pre-exposure of Galleria mellonella larvae to sub-lethal dose of Bt can elicit immune priming.•Immune priming is positively correlated with the upregulation of AMPs and ...phagocytosis.•130 significantly altered metabolites were screened using LC-MS/MS.•Immune priming could significantly change host energy and nutrient metabolisms.
Invertebrate immune priming has attracted wide attention of biologists in recent years because it challenges core notions about the disparate nature of acquired and innate immunity. However, the metabolic switch and energetic cost during eliciting immune priming are poorly investigated issues, which could widen and deepen our understanding of the physiological mechanism of immune priming. In this study, using sublethal dose of Bacillus thuringiensis (Bt) as an elicitor, we detected typical immune priming responses in Galleria mellonella. We found that the intensity of immune priming is positively correlated with the levels of antimicrobial peptides and phagocytosis ability of hemocytes. Subsequently, we employed LC-MS/MS-based untargeted metabolomics techniques to analyze the metabolic changes in the fat body of G. mellonella larvae during immune priming. The results showed that there were 74 and 56 significantly altered metabolites in positive and negative ion mode, respectively, after Bt priming. Most of the differential metabolites were enriched in the following metabolic pathways: amino acid biosynthesis, carbon metabolism, aminoacyl-tRNA biosynthesis and ABC transporters. The energetic cost of immune priming was depicted mainly in the slow growth of body mass and decreased levels of sucrose, lactose, D-ribulose 1,5-bisphosphate, Glycerate-3P and isocitric acid, which are enriched in carbon metabolism and involved in energy production. Meanwhile, correlation and interaction network analysis showed negative correlations between carbohydrates and metabolites involved in amino acid biosynthesis, suggesting that amino acids acted as the main energy source and helped the organisms synthesize immune effectors to participate in the immune priming response. Our results pave the way for uncovering the physiological mechanism of insect immune priming and discovering novel targets for Bt insecticide.
Highlights • Priming G. mellonella with high dose of heat-killed TT01 resulted in an enhanced immune protection. • Priming G. mellonella with heat-killed TT01 caused dose-dependent elevation in ...innate immunity. • Genes coding for AMPs increased in expression after priming G. mellonella with heat-killed TT01.
Highlights • Four types of hemocytes were identified in Galleria mellonella larvae. • Plasmatocytes and granular cells were the most abundant circulating cell types in the larvae. • Plasmatocytes, ...granular cells and oenocytoids of the larvae are involved in phagocytosis. • Oenocytoids, granular cells and plasmatocytes from larvae of G. mellonella have PO activity.
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