• Title/Summary/Keyword: viral

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Removal of the Glycosylation of Prion Protein Provokes Apoptosis in SF126

  • Chen, Lan;Yang, Yang;Han, Jun;Zhang, Bao-Yun;Zhao, Lin;Nie, Kai;Wang, Xiao-Fan;Li, Feng;Gao, Chen;Dong, Xiao-Ping;Xu, Cai-Min
    • BMB Reports
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    • v.40 no.5
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    • pp.662-669
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    • 2007
  • Although the function of cellular prion protein (PrP$^C$) and the pathogenesis of prion diseases have been widely described, the mechanisms are not fully clarified. In this study, increases of the portion of non-glycosylated prion protein deposited in the hamster brains infected with scrapie strain 263K were described. To elucidate the pathological role of glycosylation profile of PrP, wild type human PrP (HuPrP) and two genetic engineering generated non-glycosylated PrP mutants (N181Q/N197Q and T183A/T199A) were transiently expressed in human astrocytoma cell line SF126. The results revealed that expressions of non-glycosylated PrP induced significantly more apoptosis cells than that of wild type PrP. It illustrated that Bcl-2 proteins might be involved in the apoptosis pathway of non-glycosylated PrPs. Our data highlights that removal of glycosylation of prion protein provokes cells apoptosis.

Nonstructural NS5A Protein Regulates LIM and SH3 Domain Protein 1 to Promote Hepatitis C Virus Propagation

  • Choi, Jae-Woong;Kim, Jong-Wook;Nguyen, Lap P.;Nguyen, Huu C.;Park, Eun-Mee;Choi, Dong Hwa;Han, Kang Min;Kang, Sang Min;Tark, Dongseob;Lim, Yun-Sook;Hwang, Soon B.
    • Molecules and Cells
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    • v.43 no.5
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    • pp.469-478
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    • 2020
  • Hepatitis C virus (HCV) propagation is highly dependent on cellular proteins. To identify the host factors involved in HCV propagation, we previously performed protein microarray assays and identified the LIM and SH3 domain protein 1 (LASP-1) as an HCV NS5A-interacting partner. LASP-1 plays an important role in the regulation of cell proliferation, migration, and protein-protein interactions. Alteration of LASP-1 expression has been implicated in hepatocellular carcinoma. However, the functional involvement of LASP-1 in HCV propagation and HCV-induced pathogenesis has not been elucidated. Here, we first verified the protein interaction of NS5A and LASP-1 by both in vitro pulldown and coimmunoprecipitation assays. We further showed that NS5A and LASP-1 were colocalized in the cytoplasm of HCV infected cells. NS5A interacted with LASP-1 through the proline motif in domain I of NS5A and the tryptophan residue in the SH3 domain of LASP-1. Knockdown of LASP1 increased HCV replication in both HCV-infected cells and HCV subgenomic replicon cells. LASP-1 negatively regulated viral propagation and thereby overexpression of LASP-1 decreased HCV replication. Moreover, HCV propagation was decreased by wild-type LASP-1 but not by an NS5A binding-defective mutant of LASP-1. We further demonstrated that LASP-1 was involved in the replication stage of the HCV life cycle. Importantly, LASP-1 expression levels were increased in persistently infected cells with HCV. These data suggest that HCV modulates LASP-1 via NS5A in order to regulate virion levels and maintain a persistent infection.

Detection of Viral Hemorrhagic Septicemia Virus (VHSV) from marine fish in the South Western Coastal Area and East China Sea (남.서해안과 동중국해 자연산 어류에서 Viral Hemorrhagic Septicemia Virus(VHSV)검출)

  • Lee, Wol-La;Yun, Hyun-Mi;Kim, Seok-Ryel;Jung, Sung-Ju;Oh, Myung-Joo
    • Journal of fish pathology
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    • v.20 no.3
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    • pp.201-209
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    • 2007
  • Viral hemorrhagic septicemia (VHS) is one of the most serious viral disease of farmed rainbow trout and some marine fishes in Europe and North America. It has been reported in various marine fish species of Asian countries and induced cause mass mortality in Japanese flounder (Paralichthys olivaceus) culturing in Korea. The aims of this study were to monitor VHSV in wild marine fishes and to give critical information for controling the disease through prophylactic methods. Prevalence of the viral disease, geological distribution and reservoir of the virus were investigated using wild marine fishes captured in southern coast and east china sea for two years. (Reverse Transcriptase Polymerase Chain Reaction) RT-PCR results showed that VHSV were detected in 17 (10.6%) out of 160 fish. G gene sequences of viral strains isolated in this study were closely related to that of a reference strain, KVHS01-1, belonging to VHSV genotype Ⅰ. The results suggest that some of wild marine fishes are VHSV carriers and may spread the pathogen directly to fish farmed in coastal area.

Real-time Nucleic Acid Sequence Based Amplification (Real-time NASBA) for Detection of Norovirus

  • Lee, In-Soo;Choi, Dong-Hyuk;Lim, Jae-Won;Cho, Yoon-Jung;Jeong, Hye-Sook;Cheon, Doo-Sung;Bang, Hye-Eun;Jin, Hyun-Woo;Choi, Yeon-Im;Park, Sang-Jung;Kim, Sung-hyun;Lee, Hye-Young;Kim, Tae-Ue
    • Biomedical Science Letters
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    • v.17 no.3
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    • pp.191-196
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    • 2011
  • Noroviruses (noroV) are the major cause of nonbacterial gastroenteritis in humans worldwide. Since noroV cannot yet be cultured in vitro and their diagnosis by electron microscopy requires at least $10^6$ viral particles/g of stool a variety of molecular detection techniques represent an important step towards the detection of noroV. In the present study, we have applied real-time nucleic acid sequence-based amplification (real-time NASBA) for simultaneous detection of NoroV genogroup I (GI) and genogroup II (GII) using standard viral RNA. For real-time NASBA assay which can detected noroV GI and GII, a selective region of the genes encoding the capsid protein was used to design primers and genotype-specific molecular beacon probes. The specificity of the real-time NASBA using newly designed primers and probes were confirmed using standard viral RNA of noroV GI and GII. To determine the sensitivity of this assay, serial 10-fold dilutions of standard viral RNA of noroV GI and GII were used for reverse transcription polymerase chain reaction (RT-PCR) and real-time NASBA. The results showed that while agarose gel electrophoresis could detect RT-PCR products with 10 pg of standard viral RNA, the real-time NASBA assay could detect 100 fg of standard viral RNA. These results suggested that the real-time NASBA assay has much higher sensitivity than conventional RT-PCR assay. This assay was expected that might detect the viral RNA in the specimens which could have been false negative by RT-PCR. There were needed to perform real-time NASBA with clinical specimens for evaluating accurate sensitivity and specificity of this assay.

Immunomodulatory Effect of Mesenchymal Stem Cell-Derived Exosomes in Lipopolysaccharide-Stimulated RAW 264.7 Cells (Lipopolysaccharide로 자극한 RAW 264.7 세포에서 성체줄기세포 유래 엑소좀(exosome)의 면역 조절 효과)

  • Jung, Soo-Kyung;Park, Mi Jeong;Lee, Jienny;Byeon, Jeong Su;Gu, Na-Yeon;Cho, In-Soo;Cha, Sang-Ho
    • Microbiology and Biotechnology Letters
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    • v.44 no.3
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    • pp.383-390
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    • 2016
  • Mesenchymal stem cells (MSCs) are multipotent stem cells that can be differentiated into a variety of cell types, including adipocytes, osteoblasts, chondrocytes, β-pancreatic islet cells, and neuronal cells. MSCs have been reported to exhibit immunomodulatory effects in many diseases. Many studies have reported that MSCs have distinct roles in modulating inflammatory and immune responses by releasing bioactive molecules. Exosomes are cell-derived vesicles present in biological fluids, including the blood, urine, and cultured medium of cell cultures. In this study, we investigated the immunomodulatory effects of mouse adipose tissue-derived MSCs (mAD-MSCs), cultured medium (MSC-CM) of mAD-MSCs, and mAD-MSC-derived exosomes (MSC-Exo) on lipopolysaccharide (LPS)-induced RAW 264.7 cells. We observed that the expression levels of IL-1β, TNF-α, and IL-10 were significantly increased in LPS-stimulated RAW 264.7 cells compared to those in LPS-unstimulated RAW 264.7 cells. Additionally, these values were significantly (p < 0.05) decreased in mAD-MSCs-RAW 264.7 cell co-culture groups, MSC-CM-treated groups, and MSC-Exo-treated groups. MSCs can modulate the immune system in part by secreting cytokines and growth factors. We observed that immunomodulatory factors such as IL-1β, TNF-α, and IL-10 were secreted by mAD-MSCs under co-culturing conditions of mAD-MSCs with activated RAW 264.7 cells. In addition, mAD-MSC-derived exosomes exhibited similar immunomodulatory effects in activated RAW 264.7 cells. Therefore, our results suggest that mAD-MSCs have an immunomodulatory function through indirect contact.

Assessment of Viral Attenuation in Soil Using Probabilistic Quantitative Model (확률적 정량모델을 이용한 토양에서의 바이러스 저감 평가)

  • Park, Jeong-Ann;Kim, Jae-Hyun;Lee, In;Kim, Song-Bae
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.7
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    • pp.544-551
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    • 2011
  • The objective of this study was to analyze VIRULO model, a probabilistic quantitative model, which had been developed by US Environmental Protection Agency. The model could assess the viral attenuation capacity of soil as hydrogeologic barrier using Monte Carlo simulation. The governing equations used in the model were composed of unsaturated flow equations and viral transport equations. Among the model parameters, those related to water flow for 11 soil types were from UNDODA data, and those related to 5 virus species were from the literatures. The model compared the attenuation factor with threshold of attenuation to determine the probability of failure and presented the exceedances and Monte Carlo runs as output. The analysis indicated that among 11 USDA soil types, the viral attenuation capacity of loamy sand and sand were far lower than those of clay and silt soils. Also, there were differences in the attenuation in soil among 5 viruses with poliovirus showing the highest attenuation. The viral attenuation capacity of soil decreased sharply with increasing soil water content and increased nonlinearly with increasing soil barrier length. This study indicates that VIRULO model could be considered as a useful screening tool for viral risk assessment in subsurface environment.

Sequence and Phylogenetic Analysis of Respiratory Syncytial Virus Isolated from Korea (국내에서 유행한 Respiratory Syncytial 바이러스의 염기서열 및 계통분석)

  • Kwon, Soon-Young;Choi, Young-Ju;Kim, So-Youn;Song, Ki-Joon;Lee, Yong-Ju;Choi, Jong-Ouck;Seong, In-Wha
    • The Journal of Korean Society of Virology
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    • v.26 no.1
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    • pp.9-22
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    • 1996
  • Respiratory Syncytial virus (RSV) is an important cause of acute lower respiratory tract infections in human, with infants and young children being particularly susceptible. In the temperate zones, sharp annual outbreaks of RSV occur during the colder months, in both the northern and the southern hemisphere. RSV is unusual in that it can repeatedly reinfect individuals throughout life and infect babies in the presence of maternal antibody. RSV isolates can be divided into two subgroups, A and B, on the basis of their reactions with monoclonal antibodies, and the two subgroups are also distinct at the nucleotide sequence level. The specific diagnosis of RSV infection was best made by isolation of virus in tissue culture, identification of viral antigen, or by specific serologic procedures. Recently, rapid detection of RSV and analysis of RSV strain variation became possible by development of methods of reverse transcription and polymerase chain reaction amplification. In this study, to determine the genetic diversity of RSV found in Korea, 173 bp and 164 bp spanning selected regions of the RSV F and SH genes were enzymatically amplified and sequenced, respectively. Eight for F gene and three for SH gene were detected in 66 nasopharyngeal swap samples tested. Two major antigenic subgroups, A and B were confirmed from Korean samples (seven for subgroup A and one for subgroup B). At the nucleotide level of the F gene region, Korean subgroup A strains showed 95-99% homologies compared to the prototype A2 strain of subgroup A and 93-100% homologies among Korean subgroup A themselves. For the SH gene region, Korean subgroup A strain showed 97.5% homology compared to the prototype A2 strain of subgroup A, and Korean subgroup B strain showed 97% homology compared to the prototype 18537 strain of subgroup B. Most of base changes were transition and occured in codon position 3, which resulted in amino acid conservation. Using the maximum parsimony method, phylogenetic analysis indicated that Korean RSV strains formed a group with other RSV strains isolated from the United States, Canada, the Great Britain and Australia.

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