Biomedical subjects

Y S Jang

Publications and source records attributed to Y S Jang.

At least 19 recordsLinked to original sources

PubMed2006

Oral efficacy of Vero cell attenuated porcine epidemic diarrhea virus DR13 strain.

A Vero cell attenuated porcine epidemic diarrhea virus (PEDV) strain, DR13, was distinguished from wild-type PEDV using restriction enzyme fragment length polymorphism (RFLP). Cell attenuated DR13 was orally or intramuscularly (IM) administered to late-term pregnant sows, and mortality resulting from the highly virulent PEDV challenge was investigated in passively immunized suckling piglets of the two different groups. The mortality rate of the oral group (13%) was lower than that of the IM group (60%). In particular, the concentration of IgA against PEDV was higher in piglets of sows in the oral group, compared to the IM group. The attenuated DR13 virus remained safe, even after three backpassages in piglets. The findings of this study support the theory that the Vero cell attenuated DR13 virus may be applied as an oral vaccine for inducing specific immunity in late-term pregnant sows with a high margin of protection against PEDV infection.

Administration, Oral↗

PubMed2004

Allergen-specific immunosuppression by ovalbumin fused with diphtheria toxin in mice sensitized with albumins of different origin.

BACKGROUND: We previously reported that ovalbumin-diphtheria toxin (OVA-DT) fusion protein eliminates mast cells bearing OVA-specific IgE and protects OVA-sensitized mice from fatal anaphylaxis induced by OVA challenge. OBJECTIVE: To prove the specificity of therapeutic effect of OVA-DT to allergy induced by OVA only and not by other allergens such as human serum albumin (HSA), and to examine the cytotoxic effect of OVA-DT on B cells bearing OVA-specific IgE. METHODS: Mice were sensitized with two different antigens, OVA and HSA, and then treated with OVA-DT. The therapeutic effect of OVA-DT on the allergy response to each of allergen was evaluated by anaphylactic test. The effect of OVA-DT on the production of allergen-specific Ig isotypes of the sensitized mice and the cytotoxic effect of OVA-DT on B cells expressing OVA-specific IgE were examined. RESULTS: OVA-DT suppressed only OVA-induced allergy but not HSA-induced allergy in mice sensitized with a mixture of OVA and HSA. The suppression was prolonged even to the mice boosted with the same allergen 14 days after last treatment of OVA-DT. In addition, when the sensitized mice were boosted with the same allergens 14 days after last treatment of OVA-DT, the mice showed to increase the production of OVA-specific IgG2a/IgG3 and decreased that of OVA-specific IgE. OVA-DT targeted B cells bearing OVA-specific IgE, and killed them by DT-mediated cytotoxicity. CONCLUSION: The therapeutic effect of OVA-DT was specific to OVA-induced allergy and the suppression of OVA-induced allergy was continuously shown in the mice boosted with the same allergens. This is considered to be caused by the increase of OVA-specific IgG2a and IgG3, and because of the decrease of OVA-specific IgE by killing of B cells bearing OVA-specific IgE.

Albumins↗

PubMed2003

Expression and secretion of the heterodimeric protein interleukin-12 in plant cell suspension culture.

It has been suggested that plant cell culture is the most suitable system for producing small-to-medium quantities of specialized, expensive, and high-purity proteins. Here, we report that a heterodimeric protein, human interleukin-12 (hIL-12), was expressed and secreted into culture medium in a biologically active form. A transgenic plant expressing hIL-12 was constructed by sexual crossing of plants that expressed each subunit of the protein. From a piece of transgenic plant, callus was induced and cell suspension culture was established. The biological activity and amount of hIL-12 secreted into culture medium were analyzed using bioassays and ELISA. Analysis of cellular localization demonstrated that the protein was secreted into the culture medium together with its intrinsic signal peptide.

Culture Techniques↗

PubMed2003

Mutational analysis of forkhead transcriptional factor 2 (FOXL2) in Korean patients with blepharophimosis-ptosis-epicanthus inversus syndrome.

We screened for mutations in the forkhead transcription factor gene, FOXL2, in Korean patients with sporadic or familial blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) by polymerase chain reaction-single-stranded conformation polymorphism (PCR-SSCP) and direct sequencing. Five of nine BPES families and three of seven sporadic cases were detected to have FOXL2 mutations. We identified four types of FOXL2 mutations, two of which are novel. A new 14 bp deletion (939-952del14) causing a frameshift from G235W and the extension of the predicted protein to 527 amino acids was detected in a BPES family patient. In addition, a novel 845C > A transversion, resulting in a nonsense mutation (S203X), was found in a sporadic case of BPES. The previously reported in-frame 30 bp duplication (909-938dup30) was the most common mutation and was found in eight patients of four BPES families and one sporadic case. A known 17 bp duplication (1080-1096dup17) was observed in a sporadic BPES case. We were unable to find a causal mutation in four BPES families and four sporadic cases. These results suggest that in a fraction of BPES patients, the genetic defect might be associated with a mutation in the non-coding region of the FOXL2 gene or in other genes.

Adolescent↗

PubMed2002

Hydraulic properties and leachate level analysis of Kimpo metropolitan landfill, Korea.

Hydraulic properties of waste and cover soil from Kimpo Metropolitan Landfill were experimentally measured by laboratory tests. The degree of compaction was changed to identify the effect on hydraulic conductivity, field capacity, and permanent wilting point. Properties were utilized in developing a reliable numerical tool for leachate analysis. HELP, a simulation model for hydrologic evaluation of landfill performance, was adopted for that purpose. For calibration, results from simulation using the parameter values measured by laboratory tests were compared against the field data. The model was applied to predict the leachate level change according to the degree of compaction and cover soil thickness variation. It was found that the increase in the degree of compaction for intermediate cover soil and waste results in the decrease of field capacity and hydraulic conductivity, hence, the increase of leachate level. The effect of cover layer thickness on the leachate level was minor. Based on the findings from laboratory and numerical experiments, a guideline for reclamation practice was recommended.

Calibration↗

PubMed2001

DNA-mediated immunization of glycoprotein 350 of Epstein-Barr virus induces the effective humoral and cellular immune responses against the antigen.

Epstein-Barr virus (EBV) is a human pathogen that is involved in numerous diseases and tumors. Since the EBV infection occurs in the early ages of life, and most of the population is subsequently exposed to EBV, the conventional method of vaccination to induce the prophylactic immunity cannot be considered effective in coping with the virus infection. In this study, we tested whether the injection of a plasmid vector that contained the gene for glycoprotein 350 (gp350), which had been identified as a ligand for virus' adsorption and a target for virus neutralizing antibodies, could induce effective immune responses against the antigen. As a result, the injection of the constructed plasmid vector into mice induced the production of gp350-specific antibodies. A major isotype of the gp350-specific antibodies was IgG1. The antibodies efficiently mediated the antibody-dependent cellular cytotoxicity against the cells expressing the gp350 antigen. In addition, the injection of the constructed plasmid vector stimulated the precursor T cell population that was specific to the gp350 antigen. In addition, gp350-specific cytotoxic T lymphocytes were efficiently stimulated by the injection of the constructed plasmid vector. These results suggested that the injection of the plasmid vector, containing the gp350 gene of Epstein-Barr virus, could be one of the most effective ways to induce both prophylactic and therapeutic vaccinations against the virus infection.

Animals↗

PubMed2001

Immune induction and modulation in mice following immunization with DNA encoding F protein of respiratory syncytial virus.

Respiratory syncytial virus (RSV) is one of the principal agents of bronchiolitis and pneumonia in young children. Thus, there is a strong need to make a safe and effective vaccine against the RSV infection. DNA immunization is very effective at inducing both cellular and humoral immune responses. In this study, we inserted the RSV-F gene into expression vectors, pcDNA3.1 and pQE. These constructs were transformed into C2C12 and E. coli M15 cells, respectively. The expression of the RSV-F protein was confirmed by SDS-PAGE, followed by Western blot analyses. The immunization of pcDNA3.1-RSV-F elicited both anti-RSV-F titer in mouse sera and CTL activities with mouse splenocytes. Especially, the co-administration of IL-4, or the GM-CSF gene with the RSV-F gene construct, enhanced the production of anti-RSV-F Ab. However, this enhancement disappeared by the simultaneous injection of the Th1 and Th2 type cytokine genes. The CTL activities were affected by the co-delivery of the IFN-gamma gene, but not by Th2-type cytokines.

Aged↗

PubMed2001

Cross-linking of MHC class II molecules with anti-MHC class II antibody or epitope peptide prevents resting B lymphocyte differentiation by inhibiting NF-kappaB-dependent gene expression.

To understand the mechanism(s) involved in anti-MHC class II antibody-mediated inhibition of B lymphocyte differentiation, we investigated the influence of anti-MHC class II antibody treatment on the gene expression of IL-6 in resting B lymphocytes, which had been known to be one of the most important cytokines involved in B cell physiology. The level of the IL-6 mRNA expression in the LPS-stimulated resting B cells was remarkably reduced by treatment of the corresponding anti-MHC class II antibodies. The inhibition was exerted in haplotype-specific and dose-dependent manners. Similarly, MHC class II-restricted epitope peptides, when applied as a dimer form, revealed haplotype-specific and dose-dependent inhibitory effects on the IL-6 gene expression by the LPS-stimulated B cells. In addition, treatment of the anti-MHC class II antibody and MHC class II-restricted epitope peptide inhibited, in haplotype-specific and dose-dependent manners, the activation of NF-kappaB, which had been known to be one of the critical transcription factors involved in the IL-6 gene expression. Interestingly, however, exogenous addition of the recombinant IL-6 did not reverse this inhibitory effect by the anti-MHC class II antibody. These results suggest that conjugation of the MHC class II molecules by the anti-MHC class II antibody inhibited B cell differentiation, possibly through the interruption of signaling pathways leading to the IL-6 gene expression via NF-kappaB activation in B lymphocytes.

Animals↗

PubMed2001

Two-dimensional electrophoretic analysis of rice proteins by polyethylene glycol fractionation for protein arrays.

Two-dimensional electrophoresis (2-DE) is known as the most effective as well as one of the simplest methods for separating proteins. However, a few hundred plant leaf proteins out of thousands visualized on a 2-DE gel can be identified by chemical analysis due to the presence of ribulose bisphosphate carboxylase/oxygenase (Rubisco) that limits protein loading. We describe the extraction and fractionation technique with polyethylene glycol (PEG) to analyze rice leaf proteins. Rice proteins were extracted with Mg/NP-40 extraction buffer. The Mg/Nonidet P-40 (NP-40) buffer extract was further fractionated with PEG into three fractions: 10% PEG and 10-20% PEG precipitants and the final supernatant fraction that was precipitated with acetone. Rubisco, the most abundant rice leaf protein, was enriched in the 20% PEG precipitant. This fractionation technique analyzed at least 2,600 well-separated protein spots and exhibited less than 1.2% of noticeable overlapping spots. An immunological approach was used to verify the efficiency whether PEG fractionation technique can detect or enrich signal transduction components such as Galpha, ADP ribosylation factor, small GTP binding protein and 14-3-3. The ADP ribosylation factor (ARF) and Galpha were only detected in the PEG supernatant fraction not in the total protein fraction. The small GTP binding protein (Rab 7) was identified in the 10% PEG fraction and only faintly in the total protein fraction. The 14-3-3 protein was detected in all fractions but was especially prevalent in the 20% PEG fraction.

Blotting, Western↗

PubMed2001

A case of spontaneous pneumomediastinum and pneumopericardium in a young adult.

Spontaneous medialstinal emphysema (pneumomediastinum) and pneumopericardium may be defined as the presence of free air or gas in the mediastinal structures and in the pericardial sac without an apparent precipitating cause. It most frequently occurs in young healthy adults without serious underlying pulmonary disease. Although pneumomediastinum and pneumopericardium is often asymptomatic, it may cause pain in the neck and chest, dysphonia and shortness of breath. Treatment is supportive unless the patient has a history of trauma from foreign body aspiration. The course of spontaneous pneumomediastinum and pneumopericardium is usually benign and self-limited. A case of spontaneous pneumomediastinum, pneumopericardium and subcutaneous emphysema in a 20-year-old male is reported in this paper.

Adult↗

PubMed2000

Serologic and histopathologic study of Chlamydia pneumoniae infection in atherosclerosis: a possible pathogenetic mechanism of atherosclerosis induced by Chlamydia pneumoniae.

Chronic infection and inflammation have recently been implicated as important etiologic agents for atherosclerosis in general and, in particular, ischemic heart disease. Several agents have been suggested as possible candidates for the chronic inflammation including cytomegalovirus, Helicobacter pylori and Chlamydia pneumoniae. We hypothesized that a vascular infection with C. pneumoniae may induce a chronic inflammatory reaction in the host vascular tissue and activated inflammatory cells may express inflammatory mediators such as cyclooxygenase-2 (COX-2) and matrix metalloproteinases (MMPs). At first, we evaluated the relationship between C. pneumoniae infection and atherosclerosis indirectly by serologic study, and then, to confirm our hypothesis, we performed an immunohistochemical study of atherosclerotic plaques. The seropositive rate of anti-Chlamydia pneumoniae IgG was higher in the disease group (Group I, 59.8%, n = 254) than in the negative control group (Group III, 47.4%, n = 97) (p = 0.041), but the anti-Chlamydia pneumoniae IgA was not different in seropositivity between the two groups (Group I, 64.6%; Group III, 57.7%). The simultaneous seropositive rates of both IgG and IgA were 56.7% in Group I and 43.3% in Group III (p = 0.033). In subgroups without the conventional risk factors of atherosclerosis, these findings were more prominent. Furthermore, we performed immunohistochemical staining on the atherosclerotic aortic tissues obtained from patients that were seropositive to C. pneumoniae (n = 5), by using antibodies to C. pneumoniae, COX-2, and MMP-9. The immunoreactivity for COX-2 and MMP-9 increased in the atherosclerotic plaques itself, predominantly in the surrounding area of immunoreactive C. pneumoniae. These findings support our hypothesis and C. pneumoniae may participate in a pathogenetic mechanism for atherogenesis or progression of atherosclerosis. The present study may open a promising perspective concerning future therapeutic trials of chronic inflammation related atherogenesis under pathophysiological conditions.

Aged↗

PubMed1999

Effective immunotherapy of cancer by DNA vaccination.

Direct injection of naked plasmid DNA either intramuscularly or intradermally induces strong, long-lived cell-mediated and humoral immune responses to the antigen encoded by the gene vaccine. In the present study, we used gene vaccination with naked plasmid DNA to induce prophylactic immune responses to tumor associated antigens. MAGE-1 (melanoma antigen 1) is an ideal candidate for cancer vaccines because it belongs to a family of genes that are expressed in a number of human tumors of various histological types but not in normal adult tissues except for the testis, and because both humoral and cell-mediated immune responses against MAGE-1 antigen were detected in tumor patients. Intradermal administration of plasmid DNA encoding MAGE-1 (pcMAGE1) induced anti-MAGE-1-specific antibody in BALB/c mice. In contrast, no detectable level of anti-MAGE-1 antibody was induced by intramuscular injection of pcMAGE1. Also, intradermal injection of pcMAGE1 was capable of generating CTLs reactive with MAGE-1-transfected murine tumor cells, M-MSV-MAGE1. Most of the mice (8 out of 10) immunized with pcMAGE1 rejected the challenge of M-MSV-MAGE1 tumor cells, compared with control animals most of which developed tumors. This suggests that intradermal DNA vaccination could provide a novel immunotherapy of cancer.

Animals↗

PubMed1999

Administration of multiple cytokine genes with anti-tumor activity inhibits both tumor incidence and tumor growth.

The finding of reporter gene expression in muscle cells after intramuscular injection of a reporter gene containing DNA has suggested that injection of a certain gene in its naked form could induce an expression of the injected gene. The result proposed the concept, namely DNA or genetic vaccine technology, that injection of an antigen gene could induce a specific immune response against the antigen. Although the concept was initially applied to vaccination technology, the result also means that administration of cytokine genes with anti-tumor activity could exert their functions when they are applied as a naked form of DNA. To test the possibility, plasmid vector containing granulocyte macrophage-colony stimulation factor (GM-CSF) and interleukin-12 (IL-12) genes, which are known as one of the most potent anti-tumor cytokines, were constructed and injected into mice together with syngeneic tumor cells. When the cytokine gene containing plasmid was injected on the same day of tumor cell injection, a tumor mass developed in 4 out of 5 mice tested. Even among the 4 mice, the tumor mass of a mouse disappeared 2 weeks after tumor development. In addition, tumor generation was significantly delayed in cytokine gene injected mice and the average tumor size was about 51.5% that of vector control injected mice. These results suggested that tumor treatment through the injection of multiple cytokine genes with potent anti-tumor activity significantly inhibits tumor development and growth, and that the method could be considered as one of the tools for efficient tumor treatment.

Animals↗

PubMed1998

Cloning and analysis of the Epstein-Barr virus glycoprotein 350 genes.

Membrane glycoprotein 350 (gp350) of the Epstein-Barr virus (EBV) is considered as a major target for vaccine development, since the gp350 has been identified as the virus' mediator for receptor interaction and as an inducer of specific in vitro virus-neutralizing antibodies. In an initial attempt to develop an effective DNA vaccine against an EBV infection, gp350 genes were isolated from SNU-20 and SNU-1103 which are the EBV-infected lymphoblastoid cell lines established in Korea. In addition, the nucleotide sequences of the gp350 genes were determined and compared with those of other EBV strains such as B95-8, P3HR-1/AG876 and M81. Sequence analysis showed that similar high degrees of homology between 2 EBV strains derived from African Burkitt's lymphoma, P3HR-1 and AG876, was shown between the gp350 genes isolated from 2 EBV-infected lymphoblastoid cell lines established in Korea. Furthermore, these 2 Korean and 2 African strains displayed nearly identical patterns of sequence variations from B95-8. In addition, the sequence of the isolated gp350 genes, which have been reported to be associated with the biology of EBV infection, is analyzed.

Amino Acid Sequence↗

PubMed1998

Up-regulation of the expression of major histocompatibility complex class I antigens by plasmid DNA transfection in non-hematopoietic cells.

The effect of DNA on the surface expression of major histocompatibility (MHC) class I antigens was examined in non-hematopoietic tumor cell lines. Transfection with plasmid DNA via liposome or electroporation significantly increased the surface expression of MHC class I molecules in a transient manner. Northern blot analysis showed that levels of MHC class I mRNA were increased by DNA transfection, probably via transcriptional activation. In contrast, the expression of the MHC class II and beta-actin genes was not affected, suggesting that the up-regulation of MHC class I expression by plasmid DNA works in a gene-specific manner.

Actins↗

PubMed1998

Alteration of signal-transducing molecules in tumor-infiltrating lymphocytes and peripheral blood T lymphocytes from human colorectal carcinoma patients.

Tumor development or growth is accompanied by impaired immune responses, such as a poor proliferative response or down-regulated cytolytic T lymphocyte activity. Although recent reports have suggested that modification of the signal-transducing molecule is responsible for impaired immune responses in tumor-bearing hosts, the causes of defective immune function are not yet completely understood. Furthermore, the clinical significance of the findings is not yet clear. In this study, we investigated the alteration of several signal-transducing molecules in peripheral blood T lymphocytes (T-PBL) as well as in tumor-infiltrating lymphocytes (TIL) from human colorectal carcinoma patients and their relationship with the impaired host immune responses. A greater reduction in CD3zeta chain level was observed in TIL than in T-PBL from tumor-bearing hosts. CD3zeta chain reduction in T-PBL correlated with the clinicopathological stage of a tumor, especially with the status of lymph node metastasis. The levels of p56lck and p59fyn protein tyrosine kinase in T-PBL were also compared between tumor-bearing hosts and normal healthy volunteers. In T-PBL from tumor-bearing hosts, expression of protein tyrosine kinase p59fyn was significantly lower than that of p56lck. However, the level of CD3zeta chain expression did not correlate with T lymphocyte functions such as T lymphocyte proliferative response or allogeneic target cell lysis.

CD3 Complex↗

PubMed1997

Establishment of a transgenic tobacco cell suspension culture system for producing murine granulocyte-macrophage colony stimulating factor.

We tested if murine granulocyte-macrophage colony stimulating factor (mGM-CSF) is produced as a biologically active form through plant cell culture. The mGM-CSF gene was cloned into the plant expression vector, pBI121, and Ti-plasmid mediated transformation of tobacco leaves was conducted using Agrobacterium tumefaciens harboring the recombinant mGM-CSF (rmGM-CSF) gene. Cell suspension culture was established from the leaf-derived calli of transgenic tobacco plants. Northern blot analysis indicated the expression of the introduced mGM-CSF gene in both transgenic plant and cell suspension cultures. In addition, the biological activity of rmGM-CSF from plant cell culture was confirmed by measuring the proliferation of GM-CSF dependent FDC-P1 cells.

Agrobacterium tumefaciens↗

PubMed1997

Isolation of ALU1-P gene encoding a protein with aluminum tolerance activity from Arthrobacter viscosus.

We isolated a DNA fragment (ALU1-P) encoding a protein with an activity of aluminum tolerance from an Al tolerant soil microorganism, Arthrobacter viscosus. This microorganism was isolated from acidic tea field soils. The cloned DNA is composed of 1090 nucleotides, which has one open-reading frame without any stop codon. However, when the DNA fragment was transferred into Escherichia coli, a microorganism susceptible to Al toxicity, it endowed E. coli with Al tolerance. The deduced amino acid sequence of the DNA showed 65% identity with the protein of YbaX gene in Escherichia coli, and 51.1% identity with YB91 Haein hypothetical protein of HI1191 gene in Haemophilus influenzae. The ALU1-P gene in the expression vector produced a protein of 192 amino acids deriving a molecular weight of 21.3 kDa by using the stop codon in vector. The ALU1-P gene is a new one that has the characteristic of Al tolerance.

Aluminum↗