• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.23-23
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• 2002

In vitro matured porcine oocytes have very small volume of perivitellinespace(PVS). In these respect, the effects of sucrose and polybrene on the efficiency of gene transfer were investigated. As a gene (hGH) transfer vehicle, Vesicular stomatitis virus glycoprotein pseudotyped retroviral vector (VSV-G) was used. Sucrose treatment have no detrimental effect on the rates of cleavage and following development and induced the enlargement of PVS resulting the efficient introduction of retroviral vector stocks into PVS. (omitted)

• Parasites, Hosts and Diseases
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• v.57 no.5
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• pp.531-536
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• 2019

Cryptosporidium parvum and Giardia duodenalis are the main diarrhea-causing parasitic pathogens; however, their prevalence in Korea is unknown. Here, we conducted a survey to determine the prevalence and genotype distribution of these 2 pathogens causing acute diarrhea in 8,571 patients hospitalized in 17 Regional Institute of Health Environment sites in Korea, during 2013-2016. C. parvum and G. duodenalis were detected and genotyped by nested PCR, and the isolate were molecularly characterized by sequencing the glycoprotein 60 (Gp60) and ${\beta}-giardin$ genes, respectively. The overall prevalence of C. parvum and G. duodenalis was 0.37% (n=32) and 0.55% (n=47), respectively, and both pathogens were more prevalent in children under 9 years old. Molecular epidemiological analysis showed that the C. parvum isolates belonged to the IIa family and were subtyped as IIaA13G2R1, IIaA14G2R1, IIaA15G2R1, and IIaA18G3R1. Analysis of the ${\beta}-giardin$ gene fragment from G. duodenalis showed that all positive strains belong to assemblage A. This is the first report on the molecular epidemiology and subtyping of C. parvum and G. duodenalis in such a large number of diarrheal patients in Korea. These results highlight the need for continuous monitoring of these zoonotic pathogens and provide a basis for implementing control and prevention strategies. Further, the results might be useful for epidemiological investigation of the source of outbreak.

• Genomics & Informatics
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• v.6 no.2
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• pp.77-83
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• 2008

Human leucine-rich alpha-2-glycoprotein 1 (LRG1) was first identified as a trace protein in human serum. The primary sequence of LRG1 includes repeated leucine residues and putative membrane-binding domains. But, there is no published information on the genetic variation of this gene. In this study, LRG1 was identified as one of several upregulated genes in RA patients. We examined the expression levels of LRG1 between an RA patient and a healthy control by RT-PCR and validated that LRG1 was highly expressed in RA patients compared with controls. We identified the possible variation sites and single nucleotide polymorphisms (SNPs) in the human LRG1 gene by direct sequencing and analyzed the association of genotype and allele frequencies between RA patients and a control group without RA. We further investigated the relationship between these polymorphisms and the level of RF or anti-CCP in RA patients. We identified a total of three SNPs(g.-678A>G, g.-404C>T and g.1427T>C) and two variation sites (g.-1198delA and g.-893delA) in the LRG1 gene. Our results suggest that polymorphisms of the LRG1 gene are not associated with the susceptibility of RA in the Korean population.

• IMMUNE NETWORK
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• v.20 no.5
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• pp.41.1-41.11
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• 2020

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) is a positive-sense single-stranded RNA (+ssRNA) that causes coronavirus disease 2019 (COVID-19). The viral genome encodes twelve genes for viral replication and infection. The third open reading frame is the spike (S) gene that encodes for the spike glycoprotein interacting with specific cell surface receptor - angiotensin converting enzyme 2 (ACE2) - on the host cell membrane. Most recent studies identified a single point mutation in S gene. A single point mutation in S gene leading to an amino acid substitution at codon 614 from an aspartic acid 614 into glycine (D614G) resulted in greater infectivity compared to the wild type SARS-CoV2. We were interested in investigating the mutation region of S gene of SARS-CoV2 from Korean COVID-19 patients. New mutation sites were found in the critical receptor binding domain (RBD) of S gene, which is adjacent to the aforementioned D614G mutation residue. This specific sequence data demonstrated the active progression of SARS-CoV2 by mutations in the RBD of S gene. The sequence information of new mutations is critical to the development of recombinant SARS-CoV2 spike antigens, which may be required to improve and advance the strategy against a wide range of possible SARS-CoV2 mutations.

• Korean Journal of Veterinary Service
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• v.44 no.2
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• pp.73-83
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• 2021

Although many swine farms continuously vaccinated to sow to prevent Porcine epidemic diarrhea(PED), PED has occurred annually in swine herds in Jeonbuk province, Korea. In the present study, the small intestine and feces samples from 17 farms where severe watery diarrhea and death of newborn piglets occurred in 2019 were collected, amplified by RT-PCR and determined the complete nucleotide sequences of the spike (S) glycoprotein genes of nine Jeonbuk PEDV isolates. The spike (S) glycoprotein is an important determinant for molecular characterization and genetic relationship of PEDV. These nine complete S gene isolates were compared with other PEDV reference strains to identify the molecular diversity, phylogenetic relationships and antigenicity analysis. 9 field strains share 98.5~100% homologies with each other at the nucleotide sequence level and 97.3~100% homologies with each other at the amino acid level. The nine Jeonbuk PEDV isolates were classified into G2b group including a genetic specific signal, S-indels (insertion and deletion of S gene). In addition, comparisons the neutralizing epitopes of S gene between 9 field strains and domestic vaccine strains of Korea mutated 12-15 amino acids with SM-98-1 (G1a group) and mutated 0-3 amino acids with QIAP1401 (G2b group). Therefore, the development of G2b-based live vaccines will have to be expedited to ensure effective prevention of endemic PED in Korea. In addition, we will need to be prepared with periodic updates of preventive vaccines based on the PEDV variants for the re-emergence of a virulent strain.

• Journal of fish pathology
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• v.28 no.1
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• pp.27-35
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• 2015

VHSV is a major viral agent that affects freshwater and marine fish, causing serious economic losses in aquaculture in the world. Due to their filter-feeding activity, bivalve mollusks may act as viral transmitters after accumulation of the fish viruses released into seawater from infected fish. Amplification by RT-PCR was carried out to investigate the presence of VHSV in pacific oysters (Crassotrea gigas) and blue mussels (Mytilus edulis), inhabiting regions around aquatic farms in Korea. Primers designed from conserved regions of VHSVs allowed us to detect four different types of VHSV in a single PCR. Twenty two of the eighty four samples showed positive results of VHSV in a 2-step RT-PCR. Using six positive samples from three different regions in Korea, we cloned and sequenced the glycoprotein (G) gene (467-bp long) of VHSVs. Genetic analysis of the VHSVs detected in shellfish in various geographical areas of Korea showed highly restricted results to VHSV type Iva. This was in agreement with the reports showing only a single genotype of VHSV (Iva genotype) in outbreaks in cultured or wild fish in Korea. Consequently, we investigated VHSVs carried by bivalve mollusks inhabiting the vicinity of aquatic farms, and revealed correlationship between the type of viral accumulated in shellfish by filter-feeding, and those detected in disease outbreaks in fish.

• Biomolecules & Therapeutics
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• v.22 no.2
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• pp.114-121
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• 2014

Refractoriness of acute myeloid leukemia (AML) cells to chemotherapeutics represents a major clinical barrier. Suicide gene therapy for cancer has been attractive but with limited clinical efficacy. In this study, we investigated the potential application of herpes simplex virus thymidine kinase/ganciclovir (HSV-TK/GCV) based system to inhibit chemoresistant AML cells. We first generated Ara-C resistant K562 cells and doxorubicin-resistant THP-1 cells. We found that the HSV-TK/GCV anticancer system suppressed drug resistant leukemic cells in culture. Chemoresistant AML cell lines displayed similar sensitivity to HSV-TK/GCV. Moreover, HSV-TK/GCV killing of leukemic cells was augmented to a mild but significant extent by all-trans retinoic acid (ATRA) with concomitant upregulation of Connexin 43, a major component of gap junctions. Interestingly, HSV-TK/GCV killing was enhanced by expression of vesicular stomatitis virus G glycoprotein (VSV-G), a fusogenic membrane protein, which also increased leukemic cell fusion. Co-culture resistant cells expressing HSV-TK and cells stably transduced with VSV-G showed that expression of VSV-G could promote the bystander killing effect of HSV-TK/GCV. Furthermore, combination of HSV-TK/GCV with VSV-G plus ATRA produced more pronounced antileukemia effect. These results suggest that the HSV-TK/GCV system in combination with fusogenic membrane proteins and/or ATRA could provide a strategy to mitigate the chemoresistance of AML.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.1
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• pp.20-25
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• 2009

Xenotransplantation of pig organs into humans is a potential solution for the shortage of donor organs for transplantation. However, multiple immune barriers preclude its clinical application. In particular, the initial type of rejection in xenotransplantation is an acute cellular rejection by host $CD8^+$ cytotoxic T lymphocyte (CTL) cells that react to donor major histocompatibility complex (MHC) class I. The human cytomegalovirus (HCMV) glycoprotein Unique Short (US) 2 specifically targets MHC class I heavy chains to relocate them from the endoplasmic reticulum (ER) membrane to the cytosol, where they are degraded by the proteasome. In this study we transfected the US2 gene into minipig fetal fibroblasts and established four US2 clonal cell lines. The integration of US2 into transgenic fetal cells was confirmed using PCR and Southern blot assay. The reduction of Swine Leukocyte Antigen (SLA)-I by US2 was also detected using Flow cytometry assay (FACS). The FACS analysis of the US2 clonal cell lines demonstrated a substantial reduction in SLA-I surface expression. The level (44% to 76%) of SLA-I expression in US2 clonal cell lines was decreased relative to the control. In cytotoxicity assay the rate of $CD8^+$ T cell-mediated cytotoxicity was significantly reduced to 23.8${\pm}$15.1% compared to the control (59.8${\pm}$8.4%, p<0.05). In conclusion, US2 can directly protect against $CD8^+$-mediated cell lysis. These results indicate that the expression of US2 in pig cells may provide a new approach to overcome the CTL-mediated immune rejection in xenotransplantation.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.100-100
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• 2002

As an preliminary experiment for making transgenic animals producing human follicle stimulating hormone (hFSH), we tried to express recombinant hFSH gene in vitro. hFSH is a heterodimeric glycoprotein hormone produced in the anterior pituitary gland. The hormone is essential in the regulation of reproductive processes, such as follicular development and ovulation. Genes encoding the common gonadotrophin alpha subunit and FSH-specific beta subunit were inserted into retroviral vectors under the control of the rat beta actin promoter. Gene transfer to the Chinese hamster ovary (CHO) cells was done by infection of the retroviruses harvested from PT67 packaging cells transfected with recombinant retrovirus vector DNA. After selection with G4l8, PCR and RT-PCR analyses of the G4l8-resistant CHO cells showed successful transfer and expression of both ${\alpha}$ and ${\beta}$ fragments of the FSH gene.

• Journal of fish pathology
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• v.26 no.3
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• pp.149-161
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• 2013

Viral haemorrhagic septicaemia virus (VHSV), the causative agent of viral haemorrhagic septicaemia (VHS), is an epidemic virus of cultured olive flounder Paralichthys olivaceus in Korea. In the present study, the entire glycoprotein (G) gene including several hypervariable regions from 36 isolates of diverse geographic and host origin and 8 Korean VHSV isolates from cultured olive flounder were analyzed. Phylogenetic analysis indicated that most of Asian VHSV belong to the genotype IVa group, suggesting that they originated from a common ancestral virus. Comparative sequence analysis of the complete G protein from Korean VHSV isolates revealed 3 Korean strain-specific nucleotide residues (nucleotide number of G-region: A755, T834 and T1221). These results suggest that Korean VHSV originated from a common ancestor, but these regional specific nucleotide sequences suggest that genetic differences of VHSV are more related to geographic areas than to host fish species.