• Journal of Environmental Science International
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• v.14 no.6
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• pp.583-596
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• 2005

Samples of water, soil, and sediment were taken from 10 streams of Andong city in Gyeongbuk province in October 2004. To assess the degree of environmental pollution for each stream site, the chemical analyses of pollutants such as T-N, T-P, COD, heavy metal, organophosphorous and organochlorine pesticides, and dioxin-like PCB congeners were implemented using the standard process tests or the U. S. EPA methods. In addition, biological assessment using insect immune biomarkers was conducted on the same environmental samples to complement the chemical assessment. Except Waya stream (T-N; 2.91 mg/L, T-P; 0.16 mg/L, COD; 14.0 mg/L) with above the environmental quality standards, the T-P and COD concentrations of 9 sites are relatively low. The contents of Pb and Cd in samples taken from each stream were much lower than environmental quality standards. However, in comparison with soil samples of other streams, several times higher concentrations of Pb and Cd were found in locations at Mi, Gilan, Yeonha, and Waya stream sites. Dementon-S-methyl, diazinon, parathion, and phenthoate compounds among organophosphorous pesticides were detected as concentrations of ppb levels, respectively, from soil samples collected in the vicinity of Gilan, Mi, Norim, and Waya stream. On the other hand, 16 organochlorine pesticides and 12 dioxin-like PCB congeners selected in this study were not found in all samples. In particular, considering significant disrupting effects of Waya stream's samples on insect immune capacity, this stream seems to be contaminated with investigated and/or univestigated pollutants in this study.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.331-338
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• 2014

Cystatins (CSTs) are reversible and competitive inhibitors of C1A cysteine proteases, corresponding to papain-like cathepsins in plants and animals. A viral CST (CpBV-CST1) was identified from a polydnavirus, Cotesia plutellae bracovirus (CpBV). Our previous study indicated that a transient expression of CpBV-CST1 interfered with immune response and development of Plutella xylostella larvae. To directly demonstrate the protein function, this study produced a recombinant CpBV-CST1 protein (rCpBV-CST1) using bacterial expression system to determine its inhibitory activity against cysteine protease and to assess its physiological alteration in insect immune and development. The open reading frame of CpBV-CST1 encodes a polypeptide of 138 amino acids (${\approx}15kDa$). rCpBV-cystatin protein in BL21 STAR (DE3) competent cells containing a recombinant pGEX4T-3:CpBV-CST1 was over-expressed by 0.5 mM IPTG for 4 h. In biological activity assay, the purified rCpBV-CST1 showed a significant inhibition against papain activity. It inhibited a cellular immune response of hemocyte nodule formation in the beet armyworm, Spodoptera exigua. Moreover, its oral administration retarded larval development of the diamondback moth, Plutella xylostella in a dose-dependent manner. These results suggest that CpBV-CST1 may be applied to control insect pest populations.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.309-317
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• 1987

It was known that normal-haemolymph from the 3rd instar larvae of Lucillia illustris contain a lysozyme (or lysozyme-like substance) with bactericidal activity to fram positive bacteria, and the bactericidal activity of injured-haemolymph was increased significantly after injuring the body wall. To elucidate the defence mechanism of insect against the nonpathogenic bacteria, the immune-haemolymph against Escherichia coli K-12 was prepared after immunization. The bactericidal activity between injured and immune-haemolymph was compared, and it was revealed that the immune-haemolymph showed higher titer of bactericidal activity to fram positive bacteria as well as to Escherichia coli. The bactericidal substance from the immune-haemolymph was purified through a successive chromatographies on Sephacryl S-300 and CM-Sepharose CL-6B, and it was characterized as a basic protein in nature with heat stable property at acidic conditions.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.11a
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• pp.110-110
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• 2002

• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.1
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• pp.37-43
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• 2006

Enterococcus faecalis was isolated from the body fluid of dead Galleria mellonella larvae. Upon injection of E. faecalis into the hemocoel of G. mellonella, the bacteria destroyed parts of humoral defense systems in the hemolymph. In a test for the proteolytic activity of E. faecalis CS, it was confirmed that the enzyme degraded three well-known a-helical antimicrobial peptides, cecropin A, melittin and halocidin, and abolished their activities. We also determined putative cleavage sites on the primary sequences of three peptides through purification and mass analysis of peptide fragments digested by E. faecalis CS. Furthermore it was found that apolipophorin-III, recently known as a critical recognition protein for invading microbes in the hemolymph of G. mellonella, was also degraded by E. faecalis CS. Taken together, the present work shows that the protease in secretions from E. faecalis destroyed two critical humoral immune factors in the hemolymph of G. mellonella larvae. In addition, this paper demonstrates that the relationship between the host insect and the pathogenic bacteria might provide a valuable model system to study the enterococcal virulence mechanism, which may be relevant to mammalian pathogenesis.

• BMB Reports
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• v.41 no.2
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• pp.93-101
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• 2008

The major cell wall components of bacteria are lipopolysaccharide, peptidoglycan, and teichoic acid. These molecules are known to trigger strong innate immune responses in the host. The molecular mechanisms by which the host recognizes the peptidoglycan of Gram-positive bacteria and amplifies this peptidoglycan recognition signals to mount an immune response remain largely unclear. Recent, elegant genetic and biochemical studies are revealing details of the molecular recognition mechanism and the signalling pathways triggered by bacterial peptidoglycan. Here we review recent progress in elucidating the molecular details of peptidoglycan recognition and its signalling pathways in insects. We also attempt to evaluate the importance of this issue for understanding innate immunity.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.138-144
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• 2016

Phenoloxidase (PO) is an oxidizing enzyme and plays crucial roles in insect immunity and cuticle sclerotization. High oxidizing activity of chlorine dioxide gives effective control activities against microbes and insect pests. These allowed us to assess any inhibitory activity of chlorine dioxide against PO with respect to insect immunity. PO activities of the Indeanmeal moth, Plodia interpunctella, was detected in both hemocytes and plasma. Upon bacterial challenge, PO activity was significantly increased especially in plasma. However, the immune challenge coupled with chlorine dioxide treatment did not enhance PO activity. When different chlorine dioxide concentrations were incubated with activated PO by immune challenge, they did not inhibit the activated PO. These results indicate that chlorine dioxide suppresses PO activity by inhibiting PO activation.

• The Korean Journal of Pesticide Science
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• v.18 no.3
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• pp.181-190
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• 2014

An entomopathogenic bacterium, Bacillus thuringiensis (Bt), can sporulate along with production of insecticidal Cry toxins. Bt Cry toxins exhibit relatively narrow spectrum to target insects due to their specific interactions with midgut receptors. This study designed several strategies to enhance Bt efficacy in target insect spectrum and insecticidal activity. Four Cry toxins were purified from four different Bt strains and showed relatively narrow target insect spectrum. However, the Cry mixtures significantly expanded their target insect spectra. The additional effect of baculovirus to Cry toxin was tested with recombinant baculoviruses expressing Cry1Ac or Cry1Ca. However, the baculovirus was little effective to expand target insect spectrum. Bacterial culture broth of Xenorhabdus nematophila (Xn) significantly suppressed insect cellular immune response and increased Cry toxicity. The addition of Xn culture broth to Cry mixture significantly enhanced Bt efficacy in target insect spectrum and insecticidal activity.

• International Journal of Industrial Entomology and Biomaterials
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• v.29 no.2
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• pp.207-213
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• 2014

The structural proteins of classical swine fever virus (CSFV) consist of nucleocapsid protein C and envelope glycoprotein $E^{rns}$ (E0), E1 and E2. Among them, E2, the most immunogenic of the CSFV glycoproteins, induces a protective immune response in swine. In this study, to determine the optimal expression conditions of glycoprotein E2 using baculovirus system, we investigated the influence of insect cells and media to the expression of recombinant E2. Recombinant virus containing glycoprotein E2 coding gene was constructed with bApGOZA DNA. Expression of the glycoprotein E2 was analyzed by SDS-PAGE and Western blot analysis using anti-CSFV E2 monoclonal antibodies. Expression of glycoprotein E2 in Sf21 cells was first observed after 3 days and reached a maximum on the 5th day after infection. Furthermore, the highest levels of glycoprotein E2 expression were observed at multiplicity of infection (MOI) of 5. When three different insect cell lines (Sf21, High-Five and Se301) were tested, High-Five cells showed the highest production. In addition, four different serum-free and serum-supplemented media, respectively, were tested for the expression of glycoprotein E2 and the budded virus (BV) titers. As a result, serum-supplemented medium provided the best conditions for protein production and the BV yield.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.5
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• pp.624-633
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• 2021

This study was conducted to determine the supplemental effects of two insect meals, mealworm (MW) and black soldier fly (BSF), with high or low lipid levels in diets, on Pacific white shrimp Litopenaeus vannamei. Sardine and tuna by-product meals were used as the fish meal source in a control (Con) diet. The fish meals were replaced with MW, defatted MW (deMW), BSF or defatted BSF (deBSF), respectively. The shrimp (body weight: 0.47 g) were stocked into 20 acryl tanks (215 L) and fed the diets six times a day. After 45 days of the feeding trial, the shrimp that were fed insect meals had significantly higher phenoloxidase and superoxide dismutase activities than the shrimp fed Con diet. The gene expressions of prophenoloxidase, crustin and penaeidine-3c in shrimp hepatopancrease were also higher in shrimp that were fed the insect diets, regardless of defatting than those in shirmp that were fed Con diet. The survival against Vibrio parahaemolyticus was higher in shrimp that were fed the diets containing defatted insect meals than in shrimp that were fed Con diet. These results indicate that MW and BSF, regardless of lipid levels, could be good protein sources for the enhancement of innate immunity and anti-oxidant capacity of the shrimp.