• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.964-969
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• 1998

To investigated the anticarcinogenic activity of 70% ethanol extracts from various cereal in vitro, antimutagenic activity, inhibitory effect of DNA strand scission and tumor promotion were examined. The antimutagenic activity of the beans such as black bean and small red bean was generally higher than that of cereals examined. However inhibitory activity of 70% ethanolic extracts against DNA strand scission induced mitomycin C showed that millet, job's tear, black bean and soy bean among cereals and beans tested in this study inhibited effectively the DNA strand scission. Antioxidative activity of some cereal extracts determined by using linoleic acid model system showed that Job's tear, millet and black bean were higher antioxidative activity than other cereals and beans. Conventional short-term antipromoter assay system using activation of Epstein Barr virus (EBV) clearly demonstrated that sorghum, buckwheat, black bean and small red bean have inhibitory effects on promotion in cellular carcinogenesis.

• Molecules and Cells
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• v.44 no.10
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• pp.770-779
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• 2021

Transgenic Arabidopsis thaliana expressing an anti-rabies monoclonal antibody (mAb), SO57, was obtained using Agrobacterium-mediated floral dip transformation. The endoplasmic reticulum (ER) retention signal Lys-Asp-Glu-Leu (KDEL) was tagged to the C-terminus of the anti-rabies mAb heavy chain to localize the mAb to the ER and enhance its accumulation. When the inaccurately folded proteins accumulated in the ER exceed its storage capacity, it results in stress that can affect plant development and growth. We generated T₁ transformants and obtained homozygous T₃ seeds from transgenic Arabidopsis to investigate the effect of KDEL on plant growth. The germination rate did not significantly differ between plants expressing mAb SO57 without KDEL (SO plant) and mAb SO57 with KDEL (SOK plant). The primary roots of SOK agar media grown plants were slightly shorter than those of SO plants. Transcriptomic analysis showed that expression of all 11 ER stress-related genes were not significantly changed in SOK plants relative to SO plants. SOK plants showed approximately three-fold higher mAb expression levels than those of SO plants. Consequently, the purified mAb amount per unit of SOK plant biomass was approximately three times higher than that of SO plants. A neutralization assay revealed that both plants exhibited efficient rapid fluorescent focus inhibition test values against the rabies virus relative to commercially available human rabies immunoglobulins. KDEL did not upregulate ER stress-related genes; therefore, the enhanced production of the mAb did not affect plant growth. Thus, KDEL fusion is recommended for enhancing mAb production in plant systems.

• Korean Journal of Veterinary Service
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• v.42 no.2
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• pp.93-112
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• 2019

Calf diarrhea is a common disease in young claves and is still a major cause of productivity and economic loss in livestock farms. Fecal samples from Korean native cattle (n=100) with diarrhea from 64 farms in Gwangju area, Korea from september 2017 to December 2018 were examined for shedding of important protozoan parasitic, viral and bacterial pathogens using culture, rapid test kit and PCR methods. Of 57 (89.1%) of the 64 Korean native cattle farms examined had samples infected with at least one of the investigated pathogens. Among 100 fecal samples, 88 samples were positive for at least one the twelve pathogens and 51 samples were simultaneously positive for two or more pathogens by culture and PCR assay. Bovine group A rotavirus (BRV) was the most common pathogen, found in 43/100 (43.0%) samples on 32/64 (50.0%) farms. Subsequently, kobuvirus (30.0%), pathogenic E. coli (29.0%), bovine parvovirus (17.0%), Giardia spp. (13.0%), Eimeria spp. (10.0%), Clostridium perfringens type A (8.0%), bovine torovirus (8.0%), bovine viral diarrhea virus (6.0%), bovine coronavirus (5.0%), bovine norovirus (2.0%) and Cryptosporidium spp. (2.0%) were detected. Nebovirus, kırklareli virus, bovine adenovirus, Salmonella spp. and intestinal parasites were not detected. Of the 72 calves sampled in this age group, 64 (88.9%) samples were positive for at least one enteropathogen. BRV was identified in 34/72 (47.2%) samples from 27/48 (56.3%) farms. Subsequently, pathogenic E. coli (30.6%), kobuvirus (29.2%), BPaV (22.2%), Giardia spp. (15.3%), Eimeria spp. (9.7%), BVDV (6.9%), Cl. perfringens type A (6.9%), BCoV (4.6%) and Cryptosporidium spp. (2.8%) were detected in fecal samples. A total of ninety-six strains of E. coli were isolated from one hundred fecal samples collected from Korean native cattle with diarrhea. The presence of stx1, stx2, eaeA, LT, STa, STb, ehxA, saa, F4, F5(K99), F6, F17, F18 and F41 genes in the isolates was investigated by PCR. Out of ninety-six E. coli isolates screened for specific genes, 30 strains E. coli were identified to harbor shiga toxin-producing E. coli (STEC) 7 (7.3%), enterohemorrhagic E. coli (EHEC) 8 (8.3%), enteropathogenic E. coli (EPEC) 6 (6.3%), enterotoxigenic E. coli (ETEC) 2 (2.1%) and STEC/ETEC hybrid 7 (7.3%). This study provides epidemiological estimates of the prevalence of Korean native cattle's enteropathogens in Gwangju area, Korea, which would be used for cattle farmers and veterinarians to select appropriate therapeutic method.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.1
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• pp.74-80
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• 1988

Seasonal population changes in Laodelphax striatellus Fallen (small brown planthopper), percentage of rice black-streaked dwarf virus (RBSDV) viruliferous L. striatellus, and RBSDV infection of 11 corn hybrids were observed at various locations and years. The population size of L. striatellus was relatively small in the middle parts of Korea, but it was much greater in the southern areas. The population size of the first generation of adult L. striatellus emerged from late April to early May was similar or smaller compared with that of the second generation emerged in middle June in the middle parts of Korea. However, in the southern areas the population size of second generation was much greater than the first generation. The percentage of RBSDV viruliferous L. striatellus differed depending on the years, locations, and testing methods. The percentage of viruliferous vector was highest in southern plain areas and it tended to decrease with distance from the areas. The percentage of viruliferous vectors tested by enzyme-linked immunosorbent assay was higher than that tested by rice seedling test. The RBSDV infection rate of corn hybrids was highest at Daegu and ranged from 9 to 39% probably due to both a higher L. striatellus population and a higher percentage of viruliferous vectors. However, it was significantly lower in other areas and ranged from 0 to 13%.

• Journal of Ginseng Research
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• v.47 no.1
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• pp.123-132
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• 2023

Background: Pseudotyped virus systems that incorporate viral proteins have been widely employed for the rapid determination of the effectiveness and neutralizing activity of drug and vaccine candidates in biosafety level 2 facilities. We report an efficient method for producing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudovirus with dual luciferase and fluorescent protein reporters. Moreover, using the established method, we also aimed to investigate whether Korean Red Ginseng (KRG), a valuable Korean herbal medicine, can attenuate infectivity of the pseudotyped virus. Methods: A pseudovirus of SARS-CoV-2 (SARS-2pv) was constructed and efficiently produced using lentivirus vector systems available in the public domain by the introduction of critical mutations in the cytoplasmic tail of the spike protein. KRG extract was dose-dependently treated to Calu-3 cells during SARS2-pv treatment to evaluate the protective activity against SARS-CoV-2. Results: The use of Calu-3 cells or the expression of angiotensin-converting enzyme 2 (ACE2) in HEK293T cells enabled SARS-2pv infection of host cells. Coexpression of transmembrane protease serine subtype 2 (TMPRSS2), which is the activator of spike protein, with ACE2 dramatically elevated luciferase activity, confirming the importance of the TMPRSS2-mediated pathway during SARS-CoV-2 entry. Our pseudovirus assay also revealed that KRG elicited resistance to SARS-CoV-2 infection in lung cells, suggesting its beneficial health effect. Conclusion: The method demonstrated the production of SARS-2pv for the analysis of vaccine or drug candidates. When KRG was assessed by the method, it protected host cells from coronavirus infection. Further studies will be followed for demonstrating this potential benefit.

• Journal of Microbiology
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• v.41 no.3
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• pp.239-247
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• 2003

The LRV1-4 capsid protein possesses an endoribonuclease activity that is responsible for the single site-specific cleavage in the 5' untranslated region (UTR) of its own viral RNA genome and the formation of a conserved stem-loop structure (stem-loop IV) in the UTR is essential for the accurate RNA cleavage by the capsid protein. To delineate the nucleotide sequences, which are essential for the correct formation of the stem-loop structure for the accurate RNA cleavage by the viral capsid protein, a wildtype minimal RNA transcript (RNA 5' 249-342) and several synthetic RNA transcripts encoding point-mutations in the stem-loop region were generated in an in vitro transcription system, and used as substrates for the RNA cleavage assay and RNase mapping studies. When the RNA 5' 249-342 transcript was subjected to RNase T1 and A mapping studies, the results showed that the predicted RNA secondary structure in the stem-loop region using FOLD analysis only existed in the presence of Mg$\^$2＋/ ions, suggesting that the metal ion stabilizes the stem-loop structure of the substrate RNA in solution. When point-mutated RNA substrates were used in the RNA cleavage assay and RNase T1 mapping study, the specific nucleotide sequences in the stem-loop region were not required for the accurate RNA cleavage by the viral capsid protein, but the formation of a stem-loop like structure in a region (nucleotides from 267 to 287) stabilized by Mg$\^$2＋/ ions was critical for the accurate RNA cleavage. The RNase T1 mapping and EMSA studies revealed that the Ca$\^$2＋/ and Mn$\^$2＋/ ions, among the reagents tested, could change the mobility of the substrate RNA 5' 249-342 on a gel similarly to that of Mg$\^$2＋/ ions, but only Ca$\^$2＋/ ions identically showed the stabilizing effect of Mg$\^$2＋/ ions on the stem-loop structure, suggesting that binding of the metal ions (Mg$\^$2＋/ or Ca$\^$2＋/) onto the RNA substrate in solution causes change and stabilization of the RNA stem-loop structure, and only the substrate RNA with a rigid stem-loop structure in the essential region can be accurately cleaved by the LRV1-4 viral capsid protein.

• Korean Journal of Microbiology
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• v.51 no.3
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• pp.199-208
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• 2015

Biologics and medical devices manufactured with bovine-derived raw materials have the risk of viral contamination. Therefore, viral validation study is essential to ensure the safety of the products. Bovine adenovirus type-1 (BAdV-1) is one of the common bovine viral pathogens. For quantitative detection of BAdV-1 during the manufacture of biologics and medical devices, a TaqMan probe real-time PCR method was developed. Specific primers and TaqMan probe for amplifying and detecting BAdV-1 DNA were designed. Specificity, limit of detection (LOD), and robustness of the method was validated according to international guideline on the validation of nucleic acid amplification tests for the pathogen detection. The sensitivity of the assay was found to be $7.44{\times}10^1\;TCID_{50}/ml$. The real-time PCR method was reproducible, very specific to BAdV-1, and robust. Moreover, the method was successfully applied to the validation of Chinese Hamster Ovary (CHO)-K1 cells artificially infected with BAdV-1, a commercial CHO master bank, and bovine type 1 collagen. The overall results indicate that this rapid, specific, sensitive, and robust assay can be reliably used for quantitative detection of BAdV-1 contamination during the manufacture of biologics and medical devices using bovine-derived raw materials.

• Journal of Life Science
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• v.18 no.10
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• pp.1395-1399
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• 2008

We have recently reported the PRC1 promoter as a promoter candidate to control expression of transcriptionally targeted genes for breast cancer gene therapy. We tested whether the PRC1 promoter could be also applied for the lung cancer gene therapy. In the transient transfection assay with naked plasmids containing the luciferase fused to the PRC1 promoter, the promoter showed little activity in the normal lung cell line, MRC5. However, in the lung cancer A549 cells, PRC1 showed approximately 30-fold activation which was similar to the survivin promoter, the gene whose promoter has been already reportedas a candidate for the gene therapy of lung cancer. In viral systems, the PRC1 promoter showed approximately 75% and 66% of transcriptional activity compared to the CMV promoter in the adeno-associated virus (AAV) and the adenovirus (AV) systems, respectively. However, the PRC1 promoter in either AAV or AV showed approximately 20% activity compared to the CMV promoter in the normal lung cells. In addition, human lung tumor xenograft mice showed that the PRC1 promoter activity was as strong as the CMV activity in vivo. Taken together, these results suggested that PRC1 might be a potential promoter candidate for transcriptionally targeted lung cancer gene therapy.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.186-186
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• 1994

Many agonists have been known to activate the hydrolysis of membrane phospholipids through the bindings with corresponding receptors on the various cells. Diacylglycerol and inositol 1,4,5-trisphosphate(IP3) generated by the action of phosphoinositide-specific phospholipase C (PI-PLC) are well known second messengers for the activation of protein kinase C and the mobilization of Ca2+ in many cells. Three types of PI-PLC isozyme (${\alpha}$,${\gamma}$, and $\delta$) and several subtrpes for each type have been identified from mammalian sources by purification of enzymes and cloning of their cDNAs. Each type PI-PLC isozyme is coupled to different receptors and mediators, for example, ${\beta}$-types are coupled to the seven-transmembrane-receptors via Gq family of G-proteins and ${\beta}$-types directly to the receptor tyrosine kinases. Specific modulators for the signaling pathway through each type of PI-PLC should be very useful as potential potential candidates for lend substances in developing novel drugs. To establish the sensitive and convenient screening systems for searching modulators on PI-PLC mediated signaling, two kinds of approaches have been tried. (1) Establishment of in vitro assay condition for each type of PI-PLC isozyme: Overexpression by using vaccinia virus and purification of each isozyme was carried out for the preparation of large amounts of enaymes. Optimum and sensitive assay condition for the measurements of PI-ELC activities were established. (2) Development of the cell lines in which each type of PI-PLC is permanently overexpressed: A fibroblast cell line (3T3${\gamma}$1-7) in which PI-PLC-${\gamma}$1 was overexpressed by using pZip-neo expression vector was developed and used for the measurement of PDGF-induced IP3 formation. The responses for IP3 formed in 3T3${\gamma}$1-7 cells by the treatment of PDGF is 8 times more sensitive than those in control cells. 3T3${\gamma}$l-7 cell is useful for the screening of the inhibitors on the PDGF-induced cellular responses from large number of samples in a small volume(50 ${\mu}$l) and short time(5-15 min). Using these systems, we screened hundreds of herb-extracts for the inhibition of PDGF-induced IP3 formation and selected several extracts that showed the inhibition as the candidates for isolation and characterization of active substances. The determination of the acting point of selected extracts or fractions in the PDGF signaling pathway has been analyzing.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.1018-1023
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• 2005

Simplified procedure was developed for concentrating and detecting poliovirus and norovirus in oysters. Viruses were seeded into oyster tissue homogenates and concentrated through polyethylene glycol (PEG) precipitation, chloroform or Freon extraction, with additional PEG precipitation. Amount of viruses was evaluated using poliovirus plaque assay. Virus recovery during concentration procedure was approximately 16.4-26.0%. For defection, viral RNAs in oysters were examined using one-step RT-PCR after extraction with Trizol. Dilution or capturing of viral RNA using silica gel membrane allowed viruses to be detected by RT-PCR, whereas viruses could not be removed using $QIAshredder^{TM}$ Homogenizer, which is effective in removing RT-PCR inhibitors in lettuce and hamburgers. Freon extraction, generally used to concentrate viruses found in food, could be substituted with chloroform extraction using this procedure; no difference could be observed between detection limits of whole oyster extracts and digestive organ extracts indicating that RT-PCR inhibitors were distributed evenly throughout whole tissues. Nested PCR greatly improved efficiency of this procedure. Overall, this procedure could remove sufficient amount of inhibitors to allow detection of norovirus in oysters.