• KSBB Journal
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• v.22 no.6
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• pp.371-377
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• 2007

Polyhydroxyalkanoates (PHAs) are a family of microbial polyesters that can be produced by fermentation from renewable resources. PHAs can be used as completely biodegradable plastics or elastomers. In this paper, novel applications of PHAs in biosensor are described. A general platform technology was developed by using the substrate binding domain (SBD) of PHA depolymerase as a fusion partner to immobilize proteins of interest on PHA surface. It could be shown that the proteins fused to the SBD of PHA depolymerase could be specifically immobilized onto PHA film, PHA microbead, and microcontact printed PHA surface. We review the results obtained for monitoring the specific interaction between the SBO and PHA by using enhanced green fluorescent protein, red fluorescent protein, single chain antibody against hepatitis B virus preS2 surface protein and severe acute respiratory syndrome coronavirus surface antigen as model proteins. Thus, this system can be efficiently used for studying protein-protein and possibly protein-biomolecule interactions for various biotechnological applications.

• Journal of Veterinary Clinics
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• v.23 no.1
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• pp.9-13
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• 2006

Anaplasma phagocytophilum major surface protein-2 (Msp2 or p44) is the immunodominant outer membrane protein of the bacterium. Recently, we disclosed that Msp2 was an A. phagocytophilum adhesin for binding to host neutrophils and HL-60 cells, probably mediated by attachment to platelet selectin glycoprotein ligand-1 (PSGL-1). In this study, we further elucidated that Msp2 bound to PSGL-1/FucT IV-transfected BJAB but not nontransfected BJAB cells. Binding of recombinant Msp2 or cell (lee bacteria to the surface of PSGL-1/FucT IV-transfected BJAB cells was significantly higher than to nontransfected BJAB cells (p<0.01 and p<0.01). Also, Msp2 monoclonal antibody and soluble recombinant Msp2 as antagonist led to concentration-dependent reductions in A. phagocytophilum adhesln (p<0.05 and p<0.01) to transfected BJAB cells. Thus, we conclude that Msp2 of. A. phagocytophilum acts as an adhesin by which the bacterium binds to PSGL-1 on host neutrophils and myeloid cells.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.74-78
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• 2003

Multi-channel images of 11-MUA and 11-MUOH self-assembled monolayers were obtained by using two-dimensional surface plasmon resonance (SPR) absorption. Patterning process was simplified by exploiting direct photo-oxidation of thiol bonding (photolysis) instead of conventional photolithography. Sharper images were resolved by using a white light source in combination with a narrow bandpass filter in the visible region, minimizing the diffraction patterns on the images. The line profile calibration of the image contrast caused by different resonance conditions at each points on the sensor surface (at a fixed incident angle) enables us to discriminate the monolayer thickness in sub-nanometer scale. Furthermore, there is no signal degradation such as photo bleaching or quenching which are common in the detection methods based on the fluorescence.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.7
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• pp.1085-1091
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• 2004

Bu-Zhong-Yi-Qi- Tang extracts is a traditional oriental medicine in a mixture type exhibiting strong anti-bacterial, analgesic, and chemopreventive activities. In this study, we have evaluated effects of the total and polysaccharide fraction of Bu-Zhong-Yi-Qi- Tang extracts on the T cell proliferation, cytokine production, and induction of IL-2 receptor and MHC class n. For this experiment, we established CD4$^{＋}$ CD8$^{[-10]}$ T cell line producing IL-2 and IFN-${\gamma}$ when stimulated with ovalbumin antigen in the presence of antigen presenting cells. The significant effect of Bu-Zhong-Yi-Qi-Tang on antigen-induced T cell proliferation in the presence of antigen presenting cells was observed. The proliferation and IFN-${\gamma}$ production of T cells was increased in a dose dependent manner, and expression of IL-2 receptor on T cells and MHC class n molecule on antigen presenting cells was also induced in the presence of Bu-Zhong-Yi-Qi-Tang polysaccharide fraction. It was demonstrated that polysaccharide fraction of Bu-Zhong-Yi-Qi-Tang stimulates the antigen-induced T cell proliferation and the production of IFN-${\gamma}$ possibly through the increase of IL-2 receptor and MHC class n expression. Therefore Bu-Zhong-Yi-Qi-Tang can be regarded as a natural and useful immunomodulator having a relatively nonotoxic property. Further studies are needed to better characterize the nature of Bu-Zhong- Yi-Qi-Tang extract.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.5
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• pp.487-493
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• 2011

Alpha fetoprotein(AFP), which is serological marker for hepatocellular carcinoma, was quantitatively measured by its normal concentration, 10 ng/ml, with a label-free piezoelectric microcantilever mass sensor. The principle of detection is based on changes in the resonant frequency of the piezoelectric microcantilever before and after target molecules are attached to it, and its resonant frequency is measured electrically using a conductance spectrum. The resonant frequency of the developed sensor is approximately 1.34 MHz and the mass sensitivity is approximately 175 Hz/pg. The sensor has high reliability as mass sensor by reducing the effect of surface stress on resonant frequency due to attached proteins. 'Dip and dry' technique was used to react the sensor with reagents for immobilizing AFP antibody on the sensor and detecting AFP antigen. The measured mass of the detected AFP antigen was 6.02 pg at the concentration of 10 ng/ml, and 10.67 pg at 50 ng/ml when the immunoreaction time was 10 min.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1322-1328
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• 2006

In our previous study, a novel herb mixture (HIM-I) of Angelica gigas radix, Cnidium officinale rhizoma, and Paeonia japonica radix was developed to protect= the intestinal and immune systems and to promote their recovery from radiation damage. A new herbal composition (HemoHIM) with the high immune modulating activity was developed from HIM-I. In the present study, we examined the effects of HemoHIM on the maturation process of murine bone marrow (BM)-derived dendritic cells (DC). BM cells were cultured in the presence of iL-4 and GM-CSF and the generated immature DC were stimulated with HemoHIM for 24 hours. HemoHIM significantly enhanced the expression of co-stimulatory molecules, CD80 and CD86, especially. The activation capacity of HemoHIM-treated DC was significantly higher than that of immature DC, as analyzed by IL-2 and $IFN-\gamma$ production and proliferation of the responding T cells in the co-culture with allogeneic T cells. The antigen-presenting capacity of HemoHIN-treated DC was also increased by the co-culture with OVA-specific T cells (HS-1), as analyzed by IL-2 and $IFN-\gamma$ production and the proliferation. These results indicate that HemoHIM causes the maturation and ;Activation of DC, which may be a part of mechanisms of immunomodulation by HemoHIM.

• KSBB Journal
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• v.5 no.1
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• pp.87-94
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• 1990

Enhancement of hybridoma cell growth and monoclonal antibody(MAb) production by the addition of a small amount of serum into both serum-free medium and enriched medium was studied. The enriched medium was constructed by mixing a basal serum-free medium and a nutrient-fortified RPMI 1640 medium. It was supplemented with human serum albumin, insulin, transferrin, and monoethanolamine. It was found that addition of low concentration of serum with other serum-free supplements was favorable for growth of a mouse hybridoma 2c3.1 cells. The concentration of serum was determined to 0.5%. The maximum cell concentration obtained in this enriched medium supplemented with 0.5% fetal bovine serum (FBS) was $3.06{\times}10^6$ cells/ml and the concentration of secreted anti-Hepatitis surface antigen (antiHBsAg) MAb was $159.7{\mu\textrm{g}}\;/\;ml$ compared to $43{\mu\textrm{g}}\;/\;ml$ in RPMI 1640 medium with 10% FBS and $50{\mu\textrm{g}}\;/\;ml$ in previously-developed serum-free medium. The 2c3.1 cell growth and MAb production could be enhanced considerably by using the enriched medium supplemented with 0.5% FBS and serum-free supplements instead of RPMI 1640 medium or serum-free medium. The enhancement in MAb production in the enriched medium was more noticeable.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.231-234
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• 2001

We performed a basic experiment for rapid. on-line, real-time measurement of HBsAg by using a BIACORE biosensor, a chip-based sensor utilizing surface plasmon resonance technology to quantify the recognition and interaction of biomolecules. We immobilized an a -HBsAg antibody on a CM5 chip surface which was activated by N-hydroxysuccinimide for amine coupling with HBsAg, and measured the mass increase from the coupling. This study showed the potential of this biosensor-based method as a rapid, multi-sample, on-line assay. Once properly validated, it can serve as a more powerful method for HBsAg quantification.

• Korean Journal of Clinical Laboratory Science
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• v.40 no.2
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• pp.106-112
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• 2008

Bone marrow derived mesenchymal stem cells (BMSCs) are largely studied for their potential clinical use. But it is hard to get enough number of those cells for clinical trials and give serious pain to the patients. Adipose tissue is derived from the embryonic mesenchyme and contains a stroma that is easily isolated with large amount. This cell population (adipose derived stem cells: ADSCs) can be isolated from human lipoaspirates and like MSCs, differentiate toward the osteogenic, adipogenic, myogenic and chondrogenic lineages. To confirm whether adipose tissue contains stem cells, the ADSCs extracted from omental or subcutaneous fat tissue were expanded during third to fifth passages. The phenotype of the ADSCs was identified by the conventional cell surface markers using flow cytometry: positive for CD29 and CD44, but negative for CD34, CD45, CD117 and HLA-DR that similar to those observed on BMSCs. The ADSCs were able to differentiate into the osteoblast or adipocytes with induction media. Finally, ADACs expressed multiple CD marker antigens similar to those observed on BMSCs and differentiated into osteoblast, adipocyte. With this, human adipotissue contains multipotent cells and may represent an alternative stem cell source to bone marrow-derived MSCs.

• Korean Journal of Veterinary Research
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• v.36 no.2
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• pp.337-348
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• 1996

The proportion of leukocyte subpopulation in the host is of a great importance in understanding their functions and disease progress. Many methods have been developed to seperate leukocytes and to measure their activities. Characterization of immune cell subpopulations in Korean native cattle was performed using a set of monoclonal antibodies specific which are specific to bovine leukocyte differentiation antigen. Peripheral blood leukocytes from fifty Korean native and ten Holstein cattle were collected and analyzed for the investigation of leukocyte subpopulation by using monoclonal antibodies and flow cytometry. The result indicated that Korean native cattle have significantly higher proportion of leukocyte subpopulations expressing MHC class II molecules and BoCD4 than Holstein cattle.