• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.537-543
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• 2003

The mouse interferon gene (MuIFN-${\gamma}$) was cloned and then used to transform Saccharomyces cerevisiae. Expressed MuIFN-$\{gamma}$ protein (MuIFN-${\gamma}$) was successfully secreted into culture medium due to the presence oi the signal peptide of rice amylase 1A. Two different promoters fused to MuIFN-${\gamma}$ were tested: glyceraldehyde-3-phosphate dehydrogenase (GPD) promoter and a yeast hybrid ADH2-GPD (AG) promoter consisting of alcohol dehydrogenase II (ADH2) and GPD promoter. Using the hybrid promoter, the accumulation of MuIFN-${\gamma}$transcript was the highest after the 24 h cultivation, and then gradually decreased as the cultivation proceeded. However, both cell growth and recombinant MuIFN-${\gamma}$production reached their peaks after the 4-day cultivation. It was possible to produce 6.5 mg/l of MuIFN-${\gamma}$ without any changes in cell growth. Using GPD promoter, the MuIFN-${\gamma}$ transcript accumulation and the recombinant MuIFN-${\gamma}$ production followed the same pattern as the cell growth. However. compared to that of the hybrid promoter, the production of recombinant MuIFN-${\gamma}$ was 0.2 mg/l. The secreted MuIFN-${\gamma}$ had estimated molecular masses of 21 kDa and 23 kDa, which were larger than that of the encoded size due to glycosylation. The protection assay against the viral infection indicated that the recombinant MuIFN-${\gamma}$ was bioactive.

• Journal of Microbiology and Biotechnology
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• v.23 no.8
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• pp.1154-1158
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• 2013

Ganciclovir resistance of human cytomegalovirus is associated with mutations in the viral UL97 gene and poses severe problems for immunocompromised patients. In this study, PCR-based restriction fragment length polymorphism and sequencing analyses detected the UL97 D605E mutation in all five clinical isolates from patients with ganciclovir-resistant human cytomegalovirus infection during prolonged ganciclovir therapy, whereas the M460V mutation was only present in 1 of 5 isolates. On the other hand, the detection rates of the D605E mutation in the stored available DNA samples from the donor and allogeneic stem cell transplantation recipients were 66.7% and 93.7%, respectively, suggesting that the presence of D605E mutation was not associated with the ganciclovir exposure. Although the D605E mutation may not be related to ganciclovir resistance, we suggest that this mutation could be an important molecular marker of human cytomegalovirus evolution in East Asian countries. Moreover, the restriction fragment length polymorphism method using the restriction enzyme HaeIII, which is generally used to detect the UL97 A591V mutation, could also detect the D605E mutation and may therefore be a useful tool for future research on the investigation of UL97 gene mutations.

• Journal of Microbiology and Biotechnology
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• v.30 no.1
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• pp.38-43
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• 2020

Hand, foot, and mouth disease (HFMD) is caused by enterovirus 71 (EV71) in infants and children under six years of age. HFMD is characterized by fever, mouth ulcers, and vesicular rashes on the palms and feet. EV71 also causes severe neurological manifestations, such as brainstem encephalitis and aseptic meningitis. Recently, frequent outbreaks of EV71 have occurred in the Asia-Pacific region, but currently, no effective antiviral drugs have been developed to treat the disease. In this study, we investigated the antiviral effect of salvianolic acid B (SalB) on EV71. SalB is a major component of the Salvia miltiorrhiza root and has been shown to be an effective treatment for subarachnoid hemorrhages and myocardial infarctions. HeLa cells were cultured in 12-well plates and treated with SalB (100 or 10 ㎍/ml) and 10⁶ PFU/ml of EV71. SalB treatment (100 ㎍/ml) significantly decreased the cleavage of the eukaryotic eIF4G1 protein and reduced the expression of the EV71 capsid protein VP1. In addition, SalB treatment showed a dramatic decrease in viral infection, measured by immunofluorescence staining. The Akt signaling pathway, a key component of cell survival and proliferation, was significantly increased in EV71-infected HeLa cells treated with 100 ㎍/ml SalB. RT-PCR results showed that the mRNA for anti-apoptotic protein Bcl-2 and the cell cycle regulator Cyclin-D1 were significantly increased by SalB treatment. These results indicate that SalB activates Akt/PKB signaling and inhibits apoptosis in infected HeLa cells. Taken together, these results suggest that SalB could be used to develop a new therapeutic drug for EV71-induced HFMD.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.911-920
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• 2006

[ $CD8^+$ ] T Iymphocytes with the cytotoxic activity and capability to release various cytokines are the major players in immune responses against viral infection and cancer. To identify the proteins specific to resting or activated human CD8$^+$ T cells, human CD8$^+$ T cells were activated with anti-CD3+anti-CD28 mAb in the presence of IL-2. The solubilized proteins from resting and activated human CD8$^+$ T cells were separated by high-resolution two-dimensional polyacrylamide gel electrophoresis, and their proteomes were analyzed. Proteomic analysis of resting and activated T cells resulted in identification of 35 proteins with the altered expression. Mass spectrometry coupled with Profound and SWISS-PROT database analysis revealed that these identified proteins are to be functionally associated with cell proliferation, metabolic pathways, antigen presentation, and intracellular signal transduction pathways. We also identified six unknown proteins predicted from genomic DNA sequences specific to resting or activated CD8$^+$ T cells. Protein network studies and functional characterization of these novel proteins may provide new insight into the signaling transduction pathway of CD8$^+$ T cell activation.

• Journal of Microbiology and Biotechnology
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• v.26 no.4
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• pp.684-692
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• 2016

Acute respiratory virus infectious diseases are a growing health problem, particularly among children and the elderly. Much effort has been made to develop probiotics that prevent influenza virus infections by enhancing innate immunity in the respiratory tract until vaccines are available. Lactobacillus plantarum GB-LP2, isolated from a traditional Korean fermented vegetable, has exhibited preventive effects on influenza virus infection in mice. To identify the molecular basis of this strain, we conducted a whole-genome assembly study. The single circular DNA chromosome of 3,284,304 bp was completely assembled and 3,250 protein-encoding genes were predicted. Evolutionarily accelerated genes related to the phenotypic trait of anti-infective activities for influenza virus were identified. These genes encode three integral membrane proteins, a teichoic acid export ATP-binding protein and a glucosamine - fructose-6-phosphate aminotransferase involved in host innate immunity, the nonspecific DNA-binding protein Dps, which protects bacteria from oxidative damage, and the response regulator of the three-component quorum-sensing regulatory system, which is related to the capacity of adhesion to the surface of the respiratory tract and competition with pathogens. This is the first study to identify the genetic backgrounds of the antiviral activity in L. plantarum strains. These findings provide insight into the anti-infective activities of L. plantarum and the development of preventive probiotics.

• Journal of Microbiology and Biotechnology
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• v.29 no.11
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• pp.1817-1829
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• 2019

Porcine deltacoronavirus (PDCoV) is an emerging swine enteric coronavirus that causes diarrhea in neonatal piglets. Like other coronaviruses, PDCoV encodes at least three accessory or species-specific proteins; however, the biological roles of these proteins in PDCoV replication remain undetermined. As a first step toward understanding the biology of the PDCoV accessory proteins, we established a stable porcine cell line constitutively expressing the PDCoV NS7 protein in order to investigate the functional characteristics of NS7 for viral replication. Confocal microscopy and subcellular fractionation revealed that the NS7 protein was extensively distributed in the mitochondria. Proteomic analysis was then conducted to assess the expression dynamics of the host proteins in the PDCoV NS7-expressing cells. High-resolution two-dimensional gel electrophoresis initially identified 48 protein spots which were differentially expressed in the presence of NS7. Seven of these spots, including two up-regulated and five down-regulated protein spots, showed statistically significant alterations, and were selected for subsequent protein identification. The affected cellular proteins identified in this study were classified into functional groups involved in various cellular processes such as cytoskeleton networks and cell communication, metabolism, and protein biosynthesis. A substantial down-regulation of α-actinin-4 was confirmed in NS7-expressing and PDCoV-infected cells. These proteomic data will provide insights into the understanding of specific cellular responses to the accessory protein during PDCoV infection.

• Korean Journal of Microbiology
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• v.52 no.4
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• pp.482-486
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• 2016

Inonotus obliquus is a medicinal mushroom with a variety of biological activities. It has reported to have strong anti-cancer, antioxidant and anti-inflammatory properties. EBV+ gastric carcinoma is one of the most common EBV-associated cancers that were caused by latent EBV infection. In this study, we investigated the anti-cancer effects of ethanol extract of I. obliquus using in vivo xenograft animal models implanted with EBV+ human gastric carcinoma (SNU719). We also explored the molecular mechanisms responsible for its anti-cancer activity. The result indicated that the extract of I. obliquus had an anti-cancer effect in in vivo xenograft mice with EBV+ gastric carcinoma (SNU719). Extract of I. obliquus also showed a great effect on inducing the expression of p53, p21 and Bax in tumor tissue derived from EBV+ human gastric carcinoma, and these were correlated with increased expressions of the cleaved forms of caspase-9 and Parp. Also, I. obliquus attenuated the expression of viral proteins, BZLF-1 and LMP-2 in tumor tissue from EBV+ human gastric carcinoma.

• Korean Journal of Microbiology
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• v.39 no.2
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• pp.118-122
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• 2003

To develop vector plasmid for the bacteriophage P2-P4 system which is a useful experimental tool for the study of viral capsid assembly, we constructed a new P4-derived vector plasmid starting from P4 ash8 sid71 With recombinant DNA technology, a portion of P4 genome was deleted and tetracyclin resistance gene (terR) was introduced into P4 genome to give P4 selectivity. Resulting P4 ash8(sid71) terR was 12.09 kb long and could be converted to a viable bacteriophage with P2 infection. The burst size of induced bacteriophage form of P4 ash8(sid71) terR was determined. The CsCl buoyant equilibrium density gradient experiment of new P4 derivative suggested the upper limit of packaging capacity in P2-size head.

• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.305-311
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• 2015

In this research, we surveyed the yield change of garlic cultivation with seed bulbs according to annual field culture after induced meristem culture. From 2007 to 2013, yearly produced seed bulbs from $2^{nd}$ to $8^{th}$ generation were cultivated in the Muan field. Over the generations, the general growth characteristics such as the plant height, leaf number, leaf length and stem diameter were all decreased. When we compared the conventional seed bulbs and TCR ones, the plant height and stem diameter showed bigger difference. And the TCR seed bulbs showed a week late harvest time against the conventional ones. The yield of $2^{nd}$ generation was 72.3 g and 57.1 g for the $8^{th}$ generation. However every generation showed higher yield than conventional seed garlic's ones as 43.9 g. The yield index showed the same trend as $2^{nd}-8^{th}$ to 63% to 21%. After the tissue culture of garlics, the viral infections (OYDV and GSV) of TCR was far less than that of conventional ones. In case of LYSV, the infection ratio was 6.7% at $2^{nd}$ generation and 26% at $8^{th}$. However, the ratio was far less than that (80%) of the conventional ones.

• IMMUNE NETWORK
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• v.10 no.3
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• pp.104-108
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• 2010

CD137 (4-1BB/tnfrsf9) has been shown to co-stimulate T cells. However, agonistic anti-CD137 monoclonal antibody (mAb) treatment can suppress $CD4^+$ T cells, ameliorating autoimmune diseases, whereas it induces activation of $CD8^+$ T cells, resulting in diverse therapeutic activity in cancer, viral infection. To investigate the CD137-mediated T cell suppression mechanism, we examined whether anti-CD137 mAb treatment could affect $CD11b^+Gr-1^+$ myeloid-derived suppressor cells (MDSCs). Intriguingly, anti-CD137 mAb injection significantly increased $CD11b^+Gr-1^+$ cells, peaking at days 5 to 10 and continuing for at least 25 days. Furthermore, this cell population could suppress both $CD8^+$ T cells and $CD4^+$ T cells. Thus, this study demonstrated that, for the first time, anti-CD137 mAb treatment could induce $CD11b^+Gr-1^+$ MDSCs under normal conditions, suggesting a possible relationship between myeloid cell induction and CD137-mediated immune suppression.