• BMB Reports
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• v.46 no.5
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• pp.264-269
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• 2013

Pattern recognition receptors are known to participate in the activation of Prophenoloxidase system. In this study, a 1,3-${\beta}$-D-glucan recognition protein was detected for the first time in Antheraea pernyi larvae (Ap-${\beta}GRP$). Ap-${\beta}GRP$ was purified to 99.9% homogeneity from the hemolymph using traditional chromatographic methods. Ap-${\beta}GRP$ specifically bind 1,3-${\beta}$-D-glucan and yeast, but not E. coli or M. luteus. The 1,3-${\beta}$-D-glucan dependent phenoloxidase (PO) activity of the hemolymph inhibited by anti-Ap-${\beta}GRP$ antibody could be recovered by addition of purified Ap-${\beta}GRP$. These results demonstrate that Ap-${\beta}GRP$ acts as a biosensor of 1,3-${\beta}$-Dglucan to trigger the Prophenoloxidase system. A trace mount of 1,3-${\beta}$-D-glucan or Ap-${\beta}GRP$ alone was unable to trigger the proPO system, but they both did. Ap-${\beta}GRP$ was specifically degraded following the activation of proPO with 1,3-${\beta}$-Dglucan. These results indicate the variation in the amount of Ap-${\beta}GRP$ after specific immune challenge in A. pernyi hemolymph is an important regulation mechanism to immune response.

• IMMUNE NETWORK
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• v.8 no.1
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• pp.7-12
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• 2008

Background: Members belonging to the interferon-lambda (IFN-${\lambda}$) family exert protective action against viral infection; however, the mechanisms of their action have remained elusive. To study IFN-${\lambda}$ biology, such as endocytosis of IFN-${\lambda}$, we produced monoclonal antibodies (Abs) against human IFN-${\lambda}$ and examined their usefulness. Methods: We purified recombinant human IFN-${\lambda}$1 expressed in Escherichia coli by using affinity columns. Then, we generated hybridoma cells by fusing myeloma cells with splenocytes from IFN-${\lambda}$1-immunized mice. For evaluating the neutralizing activity of the monoclonal Abs against IFN-${\lambda}$1, we performed RT-PCR for the MxA transcript. In order to study the binding activity of IFN-${\lambda}$ and the monoclonal Ab complex on HepG2 cells, we labeled the monoclonal Ab with rhodamine and determined the fluorescence intensity. Results: Four hybridoma clones secreting Abs specific to IFN-${\lambda}$1 were generated and designated as HL1, HL2, HL3, and HL4. All the Abs reacted with IFN-${\lambda}$1 in the denatured form as well as in the native form. Abs produced by HL1, HL3, and HL4 did not neutralize the induction of the MxA gene by IFN-${\lambda}$1. We also demonstrated the binding of the HL1 monoclonal anbitody and IFN-${\lambda}$ complex on HepG2 cells. Conclusion: Monoclonal Abs against IFN-${\lambda}$1 were produced. These Abs can be used to study the cellular binding and internalization of IFN-${\lambda}$.

• Molecules and Cells
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• v.25 no.1
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• pp.78-85
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• 2008

In a search for new molecular pathways associated with asthma, we performed an mRNA differential display analysis using total RNA extracted from the tracheal tissues of ovalbumin (OVA)-challenged mice and sham controls. cDNAs corresponding to mRNAs for which expression levels were altered by OVA-challenge were isolate and sequenced. Twenty-eight genes differentially expressed in sham and OVA challenged mice were identified. A GenBank BLAST homology search revealed that they were related to cytoskeleton remodeling, transcription, protein synthesis and modification, energy production, and cell growth and differentiation. Two were selected for further characterization. Up-regulation of both the perinatal skeletal myosin heavy chain (skMHC) and fast skeletal muscle myosin light chain (skMLC) genes was confirmed by RT-PCR of trachea tissue from OVA challenged mice. Overexpression of skMLC protein was observed in the smooth muscle layers of OVA-challenged mice by immunohistochemistry, and the surface areas stained with skMLC antibody increased in the OVA-challenged mice. The overexpression of skMLC in murine asthma may be associated with the changes of bronchial smooth muscle.

• BMB Reports
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• v.37 no.3
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• pp.314-319
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• 2004

Flounder (Paralichthys olivaceus) Immunoglobulins (Igs) were purified from the serum of mouse IgG-immunized flounder by using affinity chromatography. Under denaturing conditions in SDS-PAGE, the flounder Igs appeared to be composed of 2 heavy (H) chains (72 and 77 kDa) and two light (L) chains (26 and 28 kDa). Monoclonal antibodies (MAbs) were produced by the fusion of myeloma cells (SP2/0) with Balb/c mouse spleen cells that were previously sensitized against affinity-purified flounder Igs. In a Western blot analysis, the produced MAbs, FIM511, FIM519, and FIM562 recognized both the 72 and 77 kDa H chains, 26 kDa, and 28 kDa L chain, respectively. Mouse antiserum against flounder Igs reacted more strongly with the L chain of 28 kDa than with 26 kDa, suggesting that the 28 kDa molecule is more immunogenic than the 26 kDa L chain molecule. In a FACS analysis, the ratios of the Ig+ cell population in the flounder head kidney and spleen cells were 49% and 24%, respectively. Unexpectedly, however, the ratios of the Ig+ B-like cell population in the flounder were not significantly augmented, even after the immunization of an immunogenic antigen. This suggests that the humoral immune response in fish could be considerably different from that in mammals. The produced MAbs in this study would be useful in characterizing flounder Ig+ B-like cells and in developing flounder Ig detecting an immunoassay system.

• BMB Reports
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• v.33 no.2
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• pp.97-102
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• 2000

Phosphoinositide-specific phospholipase C-${\gamma}1$ (PLC-${\gamma}1$) is a pivotal mediator in the signal transduction cascades induced by many growth factors. Using a yeast two-hybrid system, heat-shock protein 90 (Hsp90) was identified as a PLC-${\gamma}1$-binding protein. A co-immunoprecipitation experiment, using anti-PLC-${\gamma}1$ antibody, demonstrated an in vivo interaction between Hsp90 and PLC-${\gamma}1$ in the NIH-3T3 cells. The interaction in NIH-3T3 was unaffected by the PDGF treatment, inducing phosphorylation and activation of PLC-${\gamma}1$. Direct interaction between Hsp90 and PLC-${\gamma}1$ was confirmed by in vitro binding experiments using purified Hsp90 and PLC-${\gamma}1$. Furthermore, Hsp90 increased the $PIP_2$-hydrolyzing activity of PLC-${\gamma}1$ up to 2-fold at $0.1{\mu}M$ in vitro. Taken together, we show for the first time, the interaction of PLC-${\gamma}1$ with Hsp90, both in vivo and in vitro. We suggest that Hsp90 may play a role in PLC-${\gamma}1$-mediated signal transduction.

• BMB Reports
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• v.30 no.2
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• pp.101-105
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• 1997

Extracellular phospholipase $A_2$ activity has been detected in urine of patients with acute pyelonephritis (APN). This enzyme required micromolar $Ca^{2+}$ ion for its maximum activity and showed a broad range of pH (4.5~10) optimum. Urine enzyme hydrolyzed phosphatidylethanolamine (PE) and phosphatidylserine (PS) more effectively than phosphatidylcholine (PC). $PLA_2$ activity in the urine of patients with APN was about 5-fold higher than that of healthy individuals. When urine was subjected to heparinSepharose column chromatography, phospholipase $A_2$ activity was detected in both heparin-non-binding and binding fractions. Both phospholipase $A_2$ activities were sensitive less than a micromolar calcium concentration and did not react with anti-human 14-kDa group II phospholipase $A_2$ monoclonal antibody, HP-l. These findings suggest that two kinds of novel extracellular phospholipase $A_2$. which may not belong to the 14-kDa group II phospholipase $A_2$ family, exist in the urine of patients with APN.

• Biomedical Science Letters
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• v.2 no.1
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• pp.21-30
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• 1996

MAP kinases are a family of serine/threonine specific protein kinases becoming activated in response to different proliferative stimuli by phosphorylation at both threonine and tyrosine residue. Present study shows that MAP kinase was purified from P388 murine leukema cells by SP sephadex C-50, phenyl superose and Mono Q column chromatography and identified with anti-ERKl antibody by western blotting. Immnublotting analysis to the crude extract of P388 cell lysate shows 44 kD and other minor bands but partial purified fraction eluted from phenyl supherose column have 44kD and 66 kD isoform. Subcloned GST-fusion protein from N-terminal of $p56^{kk}$ was tested as a substrate for MAP kinase phosphorylation. It was showed that the wild type and mutant forms(S42A) were fully phosporylated by purified MAP kinase fraction as com-pare with the other mutant form(S59A). This finding suggest that those GST-fusion proteins may be used as substrate for the in vitro test of MAP kinase.

• Parasites, Hosts and Diseases
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• v.45 no.1 s.141
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• pp.19-26
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• 2007

This study describes the isolation of a Toxocara canis species-specific excretory-secretory(ES) antigen and the development of an enzyme-linked immunosorbent assay(ELISA) based on this antigen. Analysis of the ES antigens of T. canis, Toxocara vitulorum, Ascaris lumbricoides and Necator americanus larval antigen was performed by SDS-PAGE followed by western blotting. A 57 kDa T. canis-specific antibody fraction(TcES-57) was identified by western blotting and labelling with anti-Toxocara antibodies(from experimental rabbits and human patients) and tracing with anti-human or anti-rabbit peroxidase conjugate. No protein fraction of 57 kDa was detected in ES or larval antigens collected from T. canis, T. vitulorum, A. lumbricoides and N. americanus. Using TcES-57, a specific anti-serum was produced in rabbits and a double sandwich ELISA was developed. This test was validated using known seropositive sera from toxocariasis patients, sera from A. lumbricoides or N. americanus patients, and 50 serum samples from cats. These tests revealed that TcES-57 antigen is specific to T. canis infection and does not cross react with sera of other related infections. Thus, ELISA based on TcES-57 antigen was proven to be an effective tool in the diagnosis of toxocariasis and studies on the role of T. canis in the epidemiology of human toxocariasis.

• The Plant Pathology Journal
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• v.28 no.3
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• pp.299-305
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• 2012

Petunia hybrida is commonly used in landscapes and interiors for its attractive flower. Virus-like foliar symptoms, including a mosaic with dark green islands surrounding the veins and chlorosis on the leaf margins, were observed on a petunia plant from Icheon, Gyeonggido, Korea. Cucumber mosaic virus (CMV) was identified in the symptomatic petunia by serological testing for the presence of CMV coat protein (CP) with a direct antibody-sandwich-enzyme-linked immunosorbent assay. An agent was mechanically transmitted to indicator plant species including Chenopodium quinoa. Examination of the inoculated plant leaves by RT-PCR analysis and electron microscopy revealed the presence of specifically amplified CP products and spherical virions of approximately 28 nm in diameter, respectively, providing confirmation of a CMV infection. Analysis of CP sequences showed that CMV petunia isolate (CMVYJC) shared 82.5-100% amino acid sequence identity with CPs of representative CMV strains. Phylogenetic analysis of CPs supports that CMV-YJC is a member of CMV subgroup IA (CMV-IA) and has biological properties of CMV-IA on host species. To our knowledge, this is the first report of CMV from P. hybrida in Korea.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.186-192
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• 2001

A primary culture of human fetal hepatocytes was obtained through a therapeutic abortion process at 26 weeks of gestation period. More than $10^8$ cells were seeded on a plastic plate. These hepatocytes were infected with hepatitis B virus (HBV). The HBV was purified from serum of one chronic HBV carrier. Transformed hepatocytes were subcultured in a 10% FBS-supplemented medium. The morphology of the transformed cell was epithelial-like. The cells from the first pass showed signs of early proliferation and had a latent period of more than 3 months after 6-7 passages. After the rest period, the transformed cell proliferated actively and they were subcultured every three days. Transformed hepatocytes were characterized by detection of the HBV transcript by RT-PCR. The secretion of virions from transformed cells was investigated by PCR with the cell medium. Two types of virions secreted into the culture medium were examined by using the transmission electron microscope. Another approach to study the secretion of virions in to culture medium was carried out with HBV antibody. HBsAg was detected in the culture medium of transformed cells using ELISA and Western blot analyses. These data suggested that the human fetal hepatocyte cell line has been established by infection of HBV, in which this cell line secreted viral particles into the culture medium.