• The Plant Pathology Journal
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• 제36권3호
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• pp.280-288
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• 2020

RNA interference (RNAi) has attracted attention as a promising approach to control plant viruses in their insect vectors. In the present study, to suppress replication of the rice stripe virus (RSV) in its vector, Laodelphax striatellus, using RNAi, dsRNAs against L. striatellus genes that are strongly upregulated upon RSV infection were delivered through a rice leaf-mediated method. RNAi-based silencing of peroxiredoxin, cathepsin B, and cytochrome P450 resulted in significant down regulation of the NS3 gene of RSV, achieving a transcriptional reduction greater than 73.6% at a concentration of 100 ng/μl and, possibly compromising viral replication. L. striatellus genes might play crucial roles in the transmission of RSV; transcriptional silencing of these genes could suppress viral replication in L. striatellus. These results suggest effective RNAi-based approaches for controlling RSV and provide insight into RSV-L. striatellus interactions.

• 대한수의학회지
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• 제36권4호
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• pp.997-1005
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• 1996

For understanding the role of infectious bursal disease virus(IBDV) to the pathogenesis of necrotic enteritis due to Clostridium perfringens(CP), all 15 day-old chickens used were divided as the following groups; A and E group with the feeding of feed contaminated with CP, B group with oral adminstration of IBDV($50{\mu}l/head$, $10^{3.4}EID_{50}$ of $P_4$ strain) and simultaneously feeding of feed contaminated with CP, C group treated with IBDV alone, F group with the feeding of feed contaminated with CP at 3 weeks after oral inoculation of IBDV, D and G group with the feeding of normal feed as controls. In mortality, B group(30%) was not a difference compared to A group(20%)(p>0.05), but in the pathological lesions the former was more severe degree than the latter. The mortality of F group(70%) was a significant difference to those of A, B or E group (20%)(p<0.01). Also, showed much F group more marked lesions than A, B or E group. In the chickens occurred the death during the study, mean concentration of CP was reached at $10^8{\sim}10^9CFU/g$ in the intestinal contents. B group showed higher mortality and more severe pathological changes than A and E group. Consequently, the results in the study were confirmed that the IBDV could be a role as a enhancing factor in pathogenesis of necrotic enteritis due to CP under the field condition.

• Journal of Veterinary Science
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• 제22권2호
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• pp.20.1-20.13
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• 2021

Background: Pseudorabies virus (PRV) infection leads to high mortality in swine. Despite extensive efforts, effective treatments against PRV infection are limited. Furthermore, the inflammatory response induced by PRV strain GXLB-2013 is unclear. Objectives: Our study aimed to investigate the inflammatory response induced by PRV strain GXLB-2013, establish an inflammation model to elucidate the pathogenesis of PRV infection further, and develop effective drugs against PRV infection. Methods: Kunming mice were infected intramuscularly with medium, LPS, and different doses of PRV-GXLB-2013. Viral spread and histopathological damage to brain, spleen, and lung were determined at 7 days post-infection (dpi). Immune organ indices, levels of reactive oxygen species (ROS), nitric oxide (NO), and inflammatory cytokines, as well as levels of activity of COX-2 and iNOS were determined at 4, 7, and 14 dpi. Results: At 10⁵-10⁶ TCID₅₀ PRV produced obviously neurological symptoms and 100% mortality in mice. Viral antigens were detectable in kidney, heart, lung, liver, spleen, and brain. In addition, inflammatory injuries were apparent in brain, spleen, and lung of PRV-infected mice. Moreover, PRV induced increases in immune organ indices, ROS and NO levels, activity of COX-2 and iNOS, and the content of key pro-inflammatory cytokines, including interleukin (IL)-1β, IL-6, tumor necrosis factor-α, interferon-γ and MCP-1. Among the tested doses, 10² TCID₅₀ of PRV produced a significant inflammatory mediator increase. Conclusions: An inflammatory model induced by PRV infection was established in mice, and 10² TCID50 PRV was considered as the best concentration for the establishment of the model.

• Molecules and Cells
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• 제45권7호
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• pp.479-494
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• 2022

Human mesenchymal stem cells (MSCs) are multipotent stem cells that have been intensively studied as therapeutic tools for a variety of disorders. To enhance the efficacy of MSCs, therapeutic genes are introduced using retroviral and lentiviral vectors. However, serious adverse events (SAEs) such as tumorigenesis can be induced by insertional mutagenesis. We generated lentiviral vectors encoding the wild-type herpes simplex virus thymidine kinase (HSV-TK) gene and a gene containing a point mutation that results in an alanine to histidine substitution at residue 168 (TK(A168H)) and transduced expression in MSCs (MSC-TK and MSC-TK(A168H)). Transduction of lentiviral vectors encoding the TK(A168H) mutant did not alter the proliferation capacity, mesodermal differentiation potential, or surface antigenicity of MSCs. The MSC-TK(A168H) cells were genetically stable, as shown by karyotyping. MSC-TK(A168H) responded to ganciclovir (GCV) with an half maximal inhibitory concentration (IC₅₀) value 10-fold less than that of MSC-TK. Because MSC-TK(A168H) cells were found to be non-tumorigenic, a U87-TK(A168H) subcutaneous tumor was used as a SAE-like condition and we evaluated the effect of valganciclovir (vGCV), an oral prodrug for GCV. U87-TK(A168H) tumors were more efficiently ablated by 200 mg/kg vGCV than U87-TK tumors. These results indicate that MSC-TK(A168H) cells appear to be pre-clinically safe for therapeutic use. We propose that genetic modification with HSV-TK(A168H) makes allogeneic MSC-based ex vivo therapy safer by eliminating transplanted cells during SAEs such as uncontrolled cell proliferation.

• BMB Reports
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• 제45권3호
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• pp.165-170
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• 2012

We report here that an ethanol extract of Tetracera scandens, a Vietnamese medicinal plant, has anti-HIV activity and possesses strong inhibitory activity against HIV-1 reverse transcriptase (RTase). Using a MT-4 cell-based assay, we found that the T. scandens extract inhibited effectively HIV virus replication with an $IC_{50}$ value in the range of 2.0-2.5 ${\mu}g$/ml while the cellular toxicity value (CC50) was more than 40-50 ${\mu}g$/ml concentration, thus yielding a minimum specificity index of 20-fold. Moreover, the anti-HIV efficacy of the T. scandens extract was determined to be due, in part, to its potent inhibitory activity against HIV-1 RTase activity in vitro. The inhibitory activity against the RTase was further confirmed by probing viral cDNA production, an intermediate of viral reverse transcription, in virus-infected cells using quantitative DNA-PCR analysis. Thus, these results suggest that T. scandens can be a useful source for the isolation and development of new anti-HIV-1 inhibitor(s).

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.615-620
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• 2003

Gyrodinium impudicum strain KG03의 세포외 다당류인 p-KG03은 황함유 다당류로 항바이러스 검색 결과, 조사대상 바이러스 중 특히 뇌심근 경색바이러스 (encephalomyocarditis virus; EMCV)에 항바이러스 활성을 가지는 것으로 조사되었다.

• BMB Reports
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• 제35권5호
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• pp.459-464
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• 2002

Fusogenic liposomes that incorporate Sendai virus envelope proteins, so-called Sendai virosomes, have been developed for in vitro and in vivo genetic modification of animal cells. In this study, several different virosomes of varying lipid compositions were formulated and their in vitro gene-transfer efficiencies compared. The virosomes were prepared by quantitative reconstitution of the Sendai envelope, fusion (F) and hemagglutinin-neuraminidase (HN) proteins into liposomal vesicles. Virosomes that contained luciferase reporter genes were tested in 293 transformed human kidney cells. F/HN-virosomes that were prepared with an artificial Sendai viral envelope (ASVE-virosomes) or phosphatidylserine (PS-virosomes) exhibited an 8- or 6-fold higher gene-transfer efficiency than cationic liposomes that were made with 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP). F/HN-virosomes that were prepared with phosphatidic acid (PA-virosomes) instead of PS were less efficient in gene transfer than either ASVE- or PS-virosomes. In addition, the genetransfer capability of ASVE- and PS-virosomes was maximal at a $Ca^{2+}$ concentration of 510 mM. These results suggest that the incorporated lipid components significantly affect the in vitro gene transfer that is mediated by Sendai F/HN-virosomes.

• Journal of Microbiology
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• 제44권1호
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• pp.77-82
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• 2006

The tea looper caterpillar, Ectropis obliqua, is one of the major pests of tea bushes. E. obliqua single-nucleocapsid nucleopolyhedrovirus (EcobSNPV) has been used as a commercial pesticide for biocontrol of this insect. However only limited genetic analysis for this important virus has been done up to now. EcobSNPV was characterized in this study. Electron microscopy analysis of the occlusion body showed polyhedra of 0.7 to $1.7\;{\mu}m$ in diameter containing a single nucleocapsid per envelope of the virion. A 15.5 kb genomic fragment containing EcoRI-L, EcoRI-N and HindIII-F fragments, was sequenced. Analysis of the sequence revealed that the fragment contained eleven potential open reading frames (ORFs): lef-1, egt, 38.7k, rrl, polyhedrin, orfl629, pk-1, hoar and homologues to Spodoptera exigua multicapsid NPV (SeMNPV) ORFs 15, 28, and 29. Gene arrangement and phylogeny analysis suggest that EcobSNPV is closely related to the previously described Group II NPV. Bioassays on lethal concentration $(LC_{50}\;and\;LC_{90})$ and lethal time $(LT_{50}\;and\;LT({90})$ were conducted to test the susceptibility of E. obliqua larvae to the virus.

• 대한한의학회지
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• 제22권1호
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• pp.53-62
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• 2001

Objective : The aim of this study was to evaluate the efficacy of Injinchunggan-tang on Hepatitis C virus infection, and to clarify the mechanism of treatment by indentifying the effect of Injinchunggan-tang on cytokine secretion. Methods : In vitro model of HCV infection in MOLT 4 cell was used. The effect of Injinchunggan-tang on the attachment of HCV on MOLT 4 cell was studied by PCR method. The change of cytokine secretion according to Injinchunggan-tang treatment was investigated by ELISA. Results : Injinchunggan-tang inhibited the attachment of HCV on MOLT 4 in the concentration of $10-2{\mu\textrm{g}}/\mu\textrm{\ell}$ and $10-1{\mu\textrm{g}}/\mu\textrm{\ell}$. In cytokine assay, Injinchunggan-tang increased the secretion of IL-4 of mouse splenocytes and PBMC in 48 hour culture as well as the secretion of IL-12 of mouse splenocytes and PBMC in 48 hour culture, whereas it decreased the secretion of $IFN-{\gamma}$ of mouse splenocytes in 24 and 48 hour culture. Conclusion : The results of this study show that Injinchunggan-tang has an inhibitory effect on the attachment on HCV on Mo1t4 Cell, and that it increases the secretion of IL-4 and IL-12 of mouse splenocyte and PBMC.

• International Journal of Industrial Entomology and Biomaterials
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• 제17권1호
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• pp.153-155
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• 2008

Pathogenic infection in tasar silkworm, Antheraea mylitta Drury is common and there is a breed specific response regarding tolerance. Hence, the tolerance level of three eco-races of tasar silkworm viz. Daba, Sarihan and Raily to Antheraea mylitta cytoplasmic polyhedrosis virus (AmCPV) infection was tested. The survival of Daba, Sarihan and Raily eco-races was significantly different (p<0.05) when challenged with the same concentration ($1{\times}10^5$ polyhedra/ml) of AmCPV. Daba eco-race was more tolerant to the AmCPV infection having higher survival (65.7%) and $LC_{50}$ values (1000893.17 polyhedra/ml) of AmCPV followed by Sarihan eco-race (50.7% survival and $LC_{50}$ value of AmCPV 187203.6168 polyhedra/ml) and Raily eco-race (24.3% survival and $LC_{50}$ value of AmCPV 5176.37 polyhedra/ml). The tolerance level of Daba and Sarihan eco-races against AmCPV was more than two times than Raily eco-race.