• Molecules and Cells
• /
• v.46 no.4
• /
• pp.209-218
• /
• 2023

In induced pluripotent stem cells (iPSCs), pluripotency is induced artificially by introducing the transcription factors Oct4, Sox2, Klf4, and c-Myc. When a transgene is introduced using a viral vector, the transgene may be integrated into the host genome and cause a mutation and cancer. No integration occurs when an episomal vector is used, but this method has a limitation in that remnants of the virus or vector remain in the cell, which limits the use of such iPSCs in therapeutic applications. Chemical reprogramming, which relies on treatment with small-molecule compounds to induce pluripotency, can overcome this problem. In this method, reprogramming is induced according to the gene expression pattern of extra-embryonic endoderm (XEN) cells, which are used as an intermediate stage in pluripotency induction. Therefore, iPSCs can be induced only from established XEN cells. We induced XEN cells using small molecules that modulate a signaling pathway and affect epigenetic modifications, and devised a culture method which can produce homogeneous XEN cells. At least 4 passages were required to establish morphologically homogeneous chemically induced XEN (CiXEN) cells, whose properties were similar to those of XEN cells, as revealed through cellular and molecular characterization. Chemically iPSCs derived from CiXEN cells showed characteristics similar to those of mouse embryonic stem cells. Our results show that the homogeneity of CiXEN cells is critical for the efficient induction of pluripotency by chemicals.

• Journal of Veterinary Science
• /
• v.24 no.5
• /
• pp.55.1-55.12
• /
• 2023

Background: Peste des petits ruminants (PPR), caused by the PPR virus (PPRV), is an acute and fatal contagious disease that mainly infects goats, sheep, and other artiodactyls. Peripheral blood mononuclear cells (PBMCs) are considered the primary innate immune cells. Objectives: PBMCs derived from goats were infected with PPRV and analyzed to detect the relationship between PPRV replication and apoptosis or the inflammatory response. Methods: Quantitative real-time polymerase chain reaction was used to identify PPRV replication and cytokines expression. Flow cytometry was conducted to detect apoptosis and the differentiation of CD4⁺ and CD8⁺ T cells after PPRV infection. Results: PPRV stimulated the differentiation of CD4⁺ and CD8⁺ T cells. In addition, PPRV induced apoptosis in goat PBMCs. Furthermore, apoptosis and the inflammatory response induced by PPRV could be suppressed by Z-VAD-FMK and Z-YVAD-FMK, respectively. Moreover, the virus titer of PPRV was attenuated by inhibiting caspase-1-dependent apoptosis and inflammation. Conclusions: This study showed that apoptosis and the inflammatory response play an essential role in PPR viral replication in vitro, providing a new mechanism related to the cell host response.

• The Plant Pathology Journal
• /
• v.40 no.2
• /
• pp.125-138
• /
• 2024

Citrus yellow vein clearing virus (CYVCV) is a member of the Alphaflexiviridae family that causes yellow vein clearing symptoms on citrus leaves. A total of 118 leaf samples from nine regions of six provinces in Korea were collected from various citrus species in 2020 and 2021. Viral diagnosis using next-generation sequencing and reverse transcription polymerase chain reaction (RT-PCR) identified four viruses: citrus tristeza virus, citrus leaf blotch virus, citrus vein enation virus, and CYVCV. A CYVCV incidence of 9.3% was observed in six host plants, including calamansi, kumquat, Persian lime, and Eureka lemon. Among the citrus infected by CYVCV, only three samples showed a single infection; the other showed a mixed infection with other viruses. Eureka lemon and Persian lime exhibited yellow vein clearing, leaf distortion, and water-soak symptom underside of the leaves, while the other hosts showed only yellowing symptoms on the leaves. The complete genome sequences were obtained from five CYVCV isolates. Comparison of the isolates reported from the different geographical regions and hosts revealed the high sequence identity (95.2% to 98.8%). Phylogenetic analysis indicated that all the five isolates from Korea were clustered into same clade but were not distinctly apart from isolates from China, Pakistan, India, and Türkiye. To develop an efficient diagnosis system for the four viruses, a simultaneous detection method was constructed using multiplex RT-PCR. Sensitivity evaluation, simplex RT-PCR, and stability testing were conducted to verify the multiplex RT-PCR system developed in this study. This information will be useful for developing effective disease management strategies for citrus growers in Korea.

• IMMUNE NETWORK
• /
• v.1 no.1
• /
• pp.77-86
• /
• 2001

Background: Hepatitis C virus(HCV), a family of Flaviviridae, has a host cell-derived envelope containing a positive-stranded RNA genome, and has been known as the maj or etiological agent for chronic hepatitis, hepatic cirrhosis, and hepatocellular carcinoma. There remains a need to dissect a molecular mechanism of pathogenesis for the development of therapeutic and effective preventive measure for HCV. Identification of cellular receptor is of central importance not only to understand the viral pathogenesis, but also to exploit strategies for prevention of HCV. This study was aimed at identifying peptide mimotopes inhibiting the binding of E2 protein of HCV to MOLT-4 cell. Methods: In this study, phage peptide library displaying a random peptides consisting of 7 or 12 random peptides was employed in order to pan against E2 protein. Free HCV particles were separated from the immune complex forms by immunoprecipitation using anti-human IgG antibody, and used for HCV-capture ELISA. To identify the peptides inhibiting E2-binding to MOLT-4 cells, E2 protein was subj ect to bind to MOLT-4 cells under the competition with phage peptides. Results: Several phage peptides were selected for their specific binding to E2 protein, which showed the conserved sequence of SHFWRAP from 3 different peptide sequences. They were also able to recognize the HCV particles in the sera of HCV patients captured by monoclonal antibody against E2 protein. Two of them, showing peptide sequence of HLGPWMSHWFQR and WAPPLERSSLFY respectively, were revealed to inhibit the binding of E2 protein to MOLT-4 cell efficiently in dose dependent mode. However, few membrane-associated receptor candidates were seen using Fasta3 programe for homology search with these peptides. Conclusion: Phage peptides containing HLGPWMSHWFQR and WAPPLERSSLFY respectively, showed the inhibition of E2-binding to MOLT-4 cells. However, they did not reveal any homologues to cellular receptors from GenBank database. In further study, cellular receptor could be identified through the screening of cDNA library from MOLT-4 or hepatocytes using antibodies against these peptide mimotopes.

• Journal of Life Science
• /
• v.28 no.9
• /
• pp.1007-1015
• /
• 2018

The E6-associated protein (E6AP) is known to induce the ubiquitination and proteasomal degradation of HCV core protein and thereby directly impair capsid assembly, resulting in a decline in HCV replication. To counteract this anti-viral host defense system, HCV core protein has evolved a strategy to inhibit E6AP expression via DNA methylation. In the present study, we further explored the mechanism by which HCV core protein inhibits E6AP expression. HCV core protein upregulated both the protein levels and enzyme activities of DNA methyltransferase 1 (DNMT1), DNMT3a, and DNMT3b to inhibit E6AP expression via promoter hypermethylation in HepG2 cells but not in Hep3B cells, which do not express p53. Interestingly, p53 overexpression alone in Hep3B cells was sufficient to activate DNMTs in the absence of HCV core protein and thereby inhibit E6AP expression via promoter hypermethylation. In addition, upregulation of p53 was absolutely required for the HCV core protein to inhibit E6AP expression via promoter hypermethylation, as evidenced by both p53 knockdown and ectopic expression experiments. Accordingly, levels of the ubiquitinated forms of HCV core protein were lower in HepG2 cells than in Hep3B cells. Based on these observations, we conclude that HCV core protein evades ubiquitin-dependent proteasomal degradation in a p53-dependent manner.

• The Korean Journal of Pain
• /
• v.5 no.2
• /
• pp.258-262
• /
• 1992

Herpes zoster is an acute infectious viral disease which affects the posterior spinal root ganglion of the spinal nerve. A single posterior spinal root ganglion or a small number of adjacent ones may be affected, usually on the same side. The corresponding ganglia of the cranial nerve may also be similarly affected. The causative virus, varicella zoster, belongs to the group of host-specific DNA viruses. Postherpetic neuralgia is a continuation of herpes zoster in older patients. Although spontaneous resolution of herpes zoster may be expected in most patients, a significant number experience intractable pain. Postherpetic neuralgia is one of the most difficult problems encountered by physicians. There are many methods for management of postherpetic neuralgia, but there is no method that results in complete remission. Laser has lately come into use to reduce several acute or chronic pains. In order to determine the degree of pain relief by laser, 27 patients of postherpetic neuralgia were irradiated with He Ne, Infrared, and $CO_2$ combine scan moded lasers two to three times per week. The results were as follows: 1) The most frequent site was thoracic vertebral nerve area. 2) Patients younger than 70 years of age showed an improvement rate of 57% vs 27% for those patients older than 70 years of age. 3) Laser therapy proved effective of those patients who received the laser treatment within one month of the onset of the disease. 4) For those patients who received treatment within one month of the disease and reflecting a 50% improvement rate, the average irradiation time was 5.7.

• Journal of Microbiology and Biotechnology
• /
• v.21 no.4
• /
• pp.366-373
• /
• 2011

We characterized the proteomes of murine N2a cells following infection with three rabies virus (RV) strains, characterized by distinct virulence phenotypes (i.e., virulent BD06, fixed CVS-11, and attenuated SRV9 strains), and identified 35 changes to protein expression using two-dimensional gel electrophoresis in whole-cell lysates. The annotated functions of these proteins are involved in various cytoskeletal, signal transduction, stress response, and metabolic processes. Specifically, a-enolase, prx-4, vimentin, cytokine-induced apoptosis inhibitor 1 (CIAPIN1) and prx-6 were significantly up-regulated, whereas Trx like-1 and galectin-1 were down-regulated following infection of N2a cells with all three rabies virus strains. However, comparing expressions of all 35 proteins affected between BD06-, CVS-11-, and SRV9-infected cells, specific changes in expression were also observed. The up-regulation of vimentin, CIAPIN1, prx-4, and 14-3-3 ${\theta}/{\delta}$, and down-regulation of NDPK-B and HSP-1 with CVS and SRV9 infection were ${\geq}2$ times greater than with BD06. Meanwhile, Zfp12 protein, splicing factor, and arginine/serine-rich 1 were unaltered in the cells infected with BD06 and CVS-11, but were up-regulated in the group infected with SRV9. The proteomic alterations described here may suggest that these changes to protein expression correlate with the rabies virus' adaptability and virulence in N2a cells, and hence provides new clues as to the response of N2a host cells to rabies virus infections, and may also aid in uncovering new pathways in these cells that are involved in rabies infections. Further characterization of the functions of the affected proteins may contribute to our understanding of the mechanisms of RV infection and pathogenesis.

• Microbiology and Biotechnology Letters
• /
• v.39 no.2
• /
• pp.140-145
• /
• 2011

Porcine epidemic diarrhea virus (PEDV) infection causes acute enteritis with lethal watery diarrhea resulting in a high mortality rate in piglets. As with the other members of group 1 coronaviruses, PEDV also utilizes the host aminopeptidase N (APN) as the major cellular receptor for entry into target cells. The coronavirus spike (S) protein is known to interact with the cellular surface for viral attachment and the S1 domain of all characterized coronaviruses contains a receptor-binding domain (RBD) that mediates a specific high-affinity interaction with their respective cellular receptors. Although the RBDs of several coronaviruses have been mapped, the location of the PEDV RBD has to date not been defined. As a first step toward the identification of the region of the S protein of the PEDV that is critical for recognition with the cellular receptor, we generated a series of S1-truncated variants and examined their abilities to bind to the porcine APN (pAPN) receptor. Our data indicate that the N-terminus of the S1 domain is required for pAPN association. The results from the present study may assist in our understanding of the molecular interactions between the PEDV S protein and the pAPN receptor.

• Korean Journal Plant Pathology
• /
• v.3 no.2
• /
• pp.108-113
• /
• 1987

Rice black-streaked dwarf virus(RBSDV) was purified from infected maize leaves. Antiserum against RBSDV was prepared for virus detection by enzyme-linked immunosorbent assay(ELISA). In detection of RBSDV by ELISA, effective dilution range of antiserum extracted in RBSDV-containing host plants and insect vectors was from 320 to 2,560 times in rice plant, 320 to 5,120 in maize plant, and 160 to 2,560 times in insect vector, Laodelphax striatellus F, respectively. The percentage of viruliferous vector in overwintered nymphs of Laodelphax striatellus determined by ELISA were 3.0 in Milyang, 2.3 in Chilgok, and 3.7 in Sunsan area. Dead insect vector which could not be tested for vims infection by conventional rice seedling inoculation test could be tested by ELISA. One hundred plants of rice and maize were randomly sampled in the field and tested whether or not they were infected with RBSDV. In rice plants, 4 out of 98 plants turned out to be infected with RBSDV by ELISA. In maize plant, 3 out of 92 plants which were excepted 8 plants to be appeared symptom already were infected. As a result, ELISA could be detected even in case of symptomless plants at early stage of viral infection.

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.4
• /
• pp.595-606
• /
• 2018

Objective: The Fusarium mycotoxins of deoxynivalenol (DON) and zerolenone (ZEN) cause health hazards for both humans and farm animals. Therefore, the main intention of this study was to reveal DON and ZEN effects on the mRNA expression of pro-inflammatory cytokines and other immune related genes in the liver of piglets. Methods: In the present study, 15 six-week-old piglets were randomly assigned to the following three different dietary treatments for 4 weeks: control diet, diet containing 8 mg DON/kg feed, and diet containing 0.8 mg ZEN/kg feed. After 4 weeks, liver samples were collected and sequenced using RNA-Seq to investigate the effects of the mycotoxins on genes and gene networks associated with the immune systems of the piglets. Results: Our analysis identified a total of 249 differentially expressed genes (DEGs), which included 99 upregulated and 150 downregulated genes in both the DON and ZEN dietary treatment groups. After biological pathway analysis, the DEGs were determined to be significantly enriched in gene ontology terms associated with many biological pathways, including immune response and cellular and metabolic processes. Consistent with inflammatory stimulation due to the mycotoxin-contaminated diet, the following Kyoto encyclopedia of genes and genomes pathways, which were related to disease and immune responses, were found to be enriched in the DEGs: allograft rejection pathway, cell adhesion molecules, graft-versus-host disease, autoimmune thyroid disease (AITD), type I diabetes mellitus, human T-cell leukemia lymphoma virus infection, and viral carcinogenesis. Genome-wide expression analysis revealed that DON and ZEN treatments downregulated the expression of the majority of the DEGs that were associated with inflammatory cytokines (interleukin 10 receptor, beta, chemokine [C-X-C motif] ligand 9), proliferation (insulin-like growth factor 1, major facilitator superfamily domain containing 2A, insulin-like growth factor binding protein 2, lipase G, and salt inducible kinase 1), and other immune response networks (paired immunoglobulin-like type 2 receptor beta, Src-like-adaptor-1 [SLA1], SLA3, SLA5, SLA7, claudin 4, nicotinamide N-methyltransferase, thyrotropin-releasing hormone degrading enzyme, ubiquitin D, histone $H_2B$ type 1, and serum amyloid A). Conclusion: In summary, our results demonstrated that high concentrations DON and ZEN disrupt immune-related processes in the liver.