• Asian-Australasian Journal of Animal Sciences
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• v.17 no.11
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• pp.1591-1598
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• 2004

To isolate the $\beta$-galactosidase producing thermophilic bacteria, samples of mud and water were collected from hot springs of avolcanic area near Golden Springs in New Zealand. Among eleven isolated strains, the strain of KNOUC112 produced the highest amounts of $\beta$-galactosidase at 40 h incubation time (0.013 unit). This strain was aerobic, asporogenic bacilli, immobile, gram negative, catalase positive, oxidase positive, and pigment producing. Optimum growth was at 70-72$^{\circ}C$, pH 7.0-7.2, and it could grow in the presence of 3% NaCl. The main fatty acids of cell components were iso-15:0 (30.26%), and iso-17:0 (31.31%). Based on morphological and biochemical properties and fatty acid composition, the strain could be identified as genus Thermus, and finally as Thermus thermophilus by phylogenetic analysis based on 16S rRNA sequence. So the strain is designated as Thermus thermophilus KNOUC112. A gene from Thermus thermophilus KNOUC112 encoding $\beta$-galactosidase was amplified by PCR using redundancy primers prepared based on the structure of $\beta$-galactosidase gene of Thermus sp. A4 and Thermus sp. strain T2, cloned and expressed in E. coli JM109 DE3. The gene of Thermus thermophilus KNOUC112 $\beta$-galactosidase(KNOUC112$\beta$-gal) consisted of a 1,938 bp open reading frame, encoding a protein of 73 kDa that was composed of 645 amino acids. KNOUC112$\beta$-gal was expressed as dimer and trimer in E. coli JM109 (DE3) via pET-5b.

• Microbiology and Biotechnology Letters
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• v.39 no.4
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• pp.337-344
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• 2011

Integrase MJ1 from the bacteriophage ${\Phi}FC1$ carries out recombination between two DNA sequences (the phage attachment site, attP and the bacterial attachment site, attB) in NIH3T3 mouse cells. In this study, the integration vector containing attP, attB and the integrase gene MJ, was constructed. The integration mediated by integrase MJ1 in Escherichia coli led to excision of LacZ. Therefore, the frequency of integration was measured by the counting of the white colony, which is detectable on X-Gal plates. The extrachromosomal integration in NIH3T3 mouse cells was monitored by the expression of the green fluorescent protein (GFP) as a reporter. To demonstrate integration mediated integrase MJ1 in NIH3T3 cells, vectors containing attP and attB were co-transfected into NIH3T3 cells. The integration was confirmed by fluorescent microscopy. The expression of GFP was induced in NIH3T3 cells expressing MJ1 without accessory factors. By contrast, the excision mediated by the MJ1 between attR and attL had no effect on the expression of GFP. These results suggest that integrase MJ1 may enable a variety of genomic modifications for research and therapeutic purposes in higher living cells.

• Korean Journal of Animal Reproduction
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• v.17 no.1
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• pp.43-48
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• 1993

These experiments were carried out to construct mouse testis cDNA library and to to seen H-Y Ag gene. Mouse testis was obtained from BALB/c inbreed mouse that was after-born 1 week. Isolation of mouse testis total RNA was carried out by guanidum/cesium choloride, poly(A+) mRNAs were purified by oligo d(T)-cellulose chromatography method. To investigate protein synthesis activity, in-vitro translation carried out by total RNA and poly(A+) mRNA. The products of in-vitro translation were identified in 12.5% PAGE. Single strand DNA and double strand DNA were synthesized from poly(A+) mRNA and purified using phenol/chloroform/isoamylalcohol. Synthesized cDNA was combined with cohesive Eco RI polylinker, its recombination efficiencies were identified by X-gal and IPTG. In the cDNA library, 1$\times$107 phagemids were screened with 32P labelled probe. Hybridization were carried on $65^{\circ}C$ for 16~20hours. And 1$\times$106 phagemids were screened with rabbit-anti-H-Y. In former, select 5 positive clones, and later, 1 positive clone. Its southern blot analysis showed various size of insert cDNA from 0.7kb to 3kb.

• IMMUNE NETWORK
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• v.6 no.2
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• pp.102-110
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• 2006

Background: Dendritic cells (DC) are professional antigen-presenting cells in the immune system and can induce T cell response against virus infections, microbial pathogens, and tumors. Therefore, immunization using DC loaded with tumor-associated antigens (TAAs) is a powerful method of inducing anti-tumor immunity. For induction of effective anti-tumor immunity, antigens should be efficiently introduced into DC and presented on MHC class I molecules at high levels to activate antigen-specific $CD8^+$ T cells. We have been exploring methods for loading exogenous antigens into APC with high efficiency of Ag presentation. In this study, we tested the effect of the cationic liposome (Lipofectin) for transferring and loading exogenous model antigen (OVA protein) into BM-DC. Methods: Bone marrow-derived DC (EM-DC) were incubated with OVA-Lipofectin complexes and then co-cultured with B3Z cells. B3Z activation, which is expressed as the amount of ${\beta}$-galactosidase induced by TCR stimulation, was determined by an enzymatic assay using ${\beta}$-gal assay system. C57BL/6 mice were immunized with OVA-pulsed DC to monitor the in vivo vaccination effect. After vaccination, mice were inoculated with EG7-OVA tumor cells. Results: BM-DC pulsed with OVA-Lipofectin complexes showed more efficient presentation of OVA-peptide on MHC class I molecules than soluble OVA-pulsed DC. OVA-Lipofectin complexes-pulsed DC pretreated with an inhibitor of MHC class I-mediated antigen presentation, brefeldin A, showed reduced ability in presenting OVA peptide on their surface MHC class I molecules. Finally, immunization of OVA-Lipofectin complexes-pulsed DC protected mice against subsequent tumor challenge. Conclusion: Our data provide evidence that antigen-loading into DC using Lipofectin can promote MHC class I- restricted antigen presentation. Therefore, antigen-loading into DC using Lipofectin can be one of several useful tools for achieving efficient induction of antigen-specific immunity in DC-based immunotherapy.

• Animal cells and systems
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• v.2 no.2
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• pp.249-258
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• 1998

Obesity, one of the most common metabolic diseases in industrial countries is characterized by an increase in the number or size of adipocytes. In an effort to create transgenic mouse models for the study of obesity we developed a novel technique in which adipose tissue can be ablated genetically at will, at any specific developmental stage and/or physiological condition, by the treatment of ganciclovir. We made a series of adipocytespecific expression vectors using minimal regulatory regions of brown adipocyte-specific uncoupling protein (UCP-1) gene and adipocyte-specific aP2 gene, and then analyzed their expression characteristics in cultured cell lines. When both constructs pUCP-LacZ and paP2-LacZ were transfected transiently into differentiating 3T3-L1 (pre-while adipocytes) and HIB-1B (pre-brown adipocytes) cell lines in vitro and then monitored by X-gal staining of cells, these regulatory regions were sufficient to show proper differentiation stage-specific expression in adipocvtes. To confirm that adipocytes expressing HSV-TK controlled by these minimal requlatory elements are sufficient to kill themselves with ganciclovir treatment pUCP-TK and paP2-TK expression constructs were transfected stably into HIB-1B and 3T3-L1 cells, respectively, and their ganciclovir sensitivities were tested during in vitro differentiation of cells. As expected more than 80% of cells were dead by the 7th day of treatment with ganciclovir while negative control cells were not affected at all. The data suqqest that the constructed vectors are suitable for obtaining novel obese transqenic models based on a conditional genetic tissue ablation method.

• Journal of Life Science
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• v.33 no.5
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• pp.383-390
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• 2023

The goal of this study was to identify new bioactive peptides in extracts derived from Tenebrio molitor (T. molitor) larvae for the development of functional foods. After extraction from freeze-dried T. molitor larvae with various solvents on time course, the extracts showed the highest 2,2,1-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity at 5 and 10 hr per total protein and solid contents, respectively. When the water extract was fractionated, a high methanol concentration led to a reduced level of high-molecular-weight proteins in the centrifugal supernatant, whereas increased DPPH activity in the supernatants suggests low-molecular-weight peptides may mediate antioxidant activity in the supernatant. Most of the organic solvent partitions, excluding butanol, showed similar activities in the water phases, and the organic solvent partition fraction exhibited a 28~44% decrease in activity following heat treatment, implying that some components in the fraction become unstable in the presence of heat. The addition of proteinase K to the water extract increased DPPH activity by 10~20%, suggesting that peptides, when released from total proteins, partially increase antioxidant activity. Therefore, we suggest that the antioxidants in T. molitor larval extracts make them a potential source of functional animal food.

• 한국균학회소식:학술대회논문집
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• 2014.05a
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• pp.27-28
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• 2014

Beauveria bassiana (Cordycipitaceae, Hypocreales, Ascomycota) is an anamorphic fungus having a potential to be used as a biological control agent because it parasitizes a wide range of arthropod hosts including termites, aphids, beetles and many other insects. A number of bioactive secondary metabolites (SMs) have been isolated from B. bassiana and functionally verified. Among them, beauvericin and bassianolide are cyclic depsipeptides with antibiotic and insecticidal effects belonging to the enniatin family. Non-ribosomal peptide synthetases (NRPSs) play a crucial role in the synthesis of these secondary metabolites. NRPSs are modularly organized multienzyme complexes in which each module is responsible for the elongation of proteinogenic and non-protein amino acids, as well as carboxyl and hydroxyacids. A minimum of three domains are necessary for one NRPS elongation module: an adenylation (A) domain for substrate recognition and activation; a tholation (T) domain that tethers the growing peptide chain and the incoming aminoacyl unit; and a condensation (C) domain to catalyze peptide bond formation. Some of the optional domains include epimerization (E), heterocyclization (Cy) and oxidation (Ox) domains, which may modify the enzyme-bound precursors or intermediates. In the present study, we analyzed genomes of B. bassiana and its allied species in Hypocreales to verify the distribution of NRPS-encoding genes involving biosynthesis of beauvericin and bassianolide, and to unveil the evolutionary processes of the gene clusters. Initially, we retrieved completely or partially assembled genomic sequences of fungal species belonging to Hypocreales from public databases. SM biosynthesizing genes were predicted from the selected genomes using antiSMASH program. Adenylation (A) domains were extracted from the predicted NRPS, NRPS-like and NRPS-PKS hybrid genes, and used them to construct a phylogenetic tree. Based on the preliminary results of SM biosynthetic gene prediction in B. bassiana, we analyzed the conserved gene orders of beauvericin and bassianolide biosynthetic gene clusters among the hypocrealean fungi. Reciprocal best blast hit (RBH) approach was performed to identify the regions orthologous to the biosynthetic gene cluster in the selected fungal genomes. A clear recombination pattern was recognized in the inferred A-domain tree in which A-domains in the 1st and 2nd modules of beauvericin and bassianolide synthetases were grouped in CYCLO and EAS clades, respectively, suggesting that two modules of each synthetase have evolved independently. In addition, inferred topologies were congruent with the species phylogeny of Cordycipitaceae, indicating that the gene fusion event have occurred before the species divergence. Beauvericin and bassianolide synthetases turned out to possess identical domain organization as C-A-T-C-A-NM-T-T-C. We also predicted precursors of beauvericin and bassianolide synthetases based on the extracted signature residues in A-domain core motifs. The result showed that the A-domains in the 1st module of both synthetases select D-2-hydroxyisovalerate (D-Hiv), while A-domains in the 2nd modules specifically activate L-phenylalanine (Phe) in beauvericin synthetase and leucine (Leu) in bassianolide synthetase. antiSMASH ver. 2.0 predicted 15 genes in the beauvericin biosynthetic gene cluster of the B. bassiana genome dispersed across a total length of approximately 50kb. The beauvericin biosynthetic gene cluster contains beauvericin synthetase as well as kivr gene encoding NADPH-dependent ketoisovalerate reductase which is necessary to convert 2-ketoisovalarate to D-Hiv and a gene encoding a putative Gal4-like transcriptional regulator. Our syntenic comparison showed that species in Cordycipitaceae have almost conserved beauvericin biosynthetic gene cluster although the gene order and direction were sometimes variable. It is intriguing that there is no region orthologous to beauvericin synthetase gene in Cordyceps militaris genome. It is likely that beauvericin synthetase was present in common ancestor of Cordycipitaceae but selective gene loss has occurred in several species including C. militaris. Putative bassianolide biosynthetic gene cluster consisted of 16 genes including bassianolide synthetase, cytochrome P450 monooxygenase, and putative Gal4-like transcriptional regulator genes. Our synteny analysis found that only B. bassiana possessed a bassianolide synthetase gene among the studied fungi. This result is consistent with the groupings in A-domain tree in which bassianolide synthetase gene found in B. bassiana was not grouped with NRPS genes predicted in other species. We hypothesized that bassianolide biosynthesizing cluster genes in B. bassiana are possibly acquired by horizontal gene transfer (HGT) from distantly related fungi. The present study showed that B. bassiana is the only species capable of producing both beauvericin and bassianolide. This property led to B. bassiana infect multiple hosts and to be a potential biological control agent against agricultural pests.

• Korean Journal of Head & Neck Oncology
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• v.19 no.1
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• pp.25-33
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• 2003

Background and Objectives: The Herpes Simplex type 2 Defective Infectious Single Cycle virus (DISC virus) is attenuated virus originally produced as viral vaccines but are also efficient gene transfer vehicle. The main goals of this study were to examine the efficiencies of the gene transfer using DISC vectors for various head and neck squamous cell carcinoma cell lines and to evaluate the efficacy of vaccination with DISC virus carrying a immunomodulatory genes (GM-CSF) as cancer therapy in a organotopic oral cavity squamous cell cancer model. Materials and Methods : We determinated the gene transfer efficiency of DISC virus by x-gal stain method and proved gene and protein expression of DISC-GMCSF transfected SCCVII cells by RT-PCR and ELISA method. Also we evaluated the ex vivo vaccination effects of SCCVII/GMCSF (DISC-GMCSF transfected SCCVII vaccine) vaccine on preventing the recurrence of micro-residual tumor. After the vaccination of SCCVII/GMCSF, specific cytotoxic T-cell responses was evaluated by CTL assay. Results: At an MOI of 10 DISC virus showed 64-88% of transfection rates in various head and neck squamous cancer cell lines. SCCVII cells transduced by DISC virus vector (MOI=10) carrying the GM-CSF gene, produced 4.5 nanogram quantities of GM-CSF per $10^6$ cells. In vivo vaccination using tumor cells transduced ex vivo with DISC-GMCSF resulted in better protection rate against subsequent tumor recurrence in organotopic oral cavity cancer model. Although tumor free survival rate was not statistically significantly increased in vaccination group (p=0.078), tumor specific cytotocic T-cell responses were significantly increased in SCCVII/GMCSF vaccination group. Conclusion: These data demonstrate that; 1) The DISC virus vector is capable of efficient gene transfer to various head and neck squamous cancer cell lines, 2) GM-CSF secreting genetically modified tumor vaccine (SCCVII/GMCSF) efficiently protected against tumor recurrence in organotopic micro-residual oral cavity cancer model and produced tumor specific cytotoxic T-cell response. DISC virus-mediated, cytokine gene transfer may prove to be useful as a clinical therapy for head and neck cancers.