• Parasites, Hosts and Diseases
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• 제32권4호
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• pp.277-280
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• 1994

폐흡충의 피낭유충이 종숙주에 도입되면 십이지장에서 탈낭하여 장벽을 통과하고. 복강과 흉강을 돌아다닌 후 8주일이면 성충으로 발육한다. 이 연구에서는 종숙주에서 발육중인 폐흡충 발육단계의 어느 시기까지 종숙주에 대한 감염력을 유지하는지를 관찰하였다. 가재에서 분리한 폐흡충 피낭유충을 고양이에 경구감염(경구감염) 시키고 3일 7일, 10일, 14일, 21일 및 28일 후 각 발육단계의 충페론 얻었다. 그리고 각 단계를 고양이에 다시 경구감염시킨 다음 1-12주일 후 고양이를 해부하여 감염 여부를 조사하였다. 종숙주에서 3일간 발육한 충체와 7일간 발육한 충체를 경구감염시킨 고양이에서 각각 투여 충체수의 31.4% 및 22.6%를 검출하였다. 종숙주에서 10일, 14일, 21일, 28일간 성장 발육한 충체를 경구감염시킨 고양이에서는 감염충체를 발견할 수 없었다. 이상의 결과 종숙주에서 최소한 7일간 발육한 폐흡충의 유충은 다시 종숙주를 감염시킬 수 있는 능력을 지니고 있었다.

• The Plant Pathology Journal
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• 제22권3호
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• pp.255-259
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• 2006

The pathogenicity to pear trees and other experimental hosts of the Apple stem grooving virus Korean isolate (ASGV-K) carried by a fungal vector, Talaromyces flavus was examined. ASGV-harboring T. flavus induced mild symptoms on virus-free pears. Symptom severity was intermediate between pears showing typical PBNLS and virus-free pears. Ten cultivars of Phaseolus vulgaris showed 35%-90% infectivity by direct infiltration into leaves and roots by ASGV-harboring T. flavus. Application of fungal cultures to soils showed 0%-70% infectivity depending on the P. vulgaris cultivar. Sap extracted from ASGV-infected Chenopodium quinoa induced similar symptoms on P. vulgaris at 25 days after inoculation. Similar symptoms were also detected on P. vulgaris which were inoculated with ASGV-harboring T.flavus. When healthy P. vulgaris leaves were challenged with sap extracted from P. vulgaris leaves infected with ASGV-harboring T. flavus, typical symptoms were observed. These data suggest that T. flavus mediates the transfer of ASGV to host plants.

• 한국가축번식학회지
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• 제25권2호
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• pp.171-180
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• 2001

형질전환 가금의 생산에 있어서 retrovirus vector를 이용하는 방법은 다양한 종류의 표적세포에 대하여 retrovirus 고유의 감염성에 의한 외래 유전자의 전이가 용이하고, 전이된 유전자가 진정염색질 영역 내로 선택적으로 도입될 수 있으며 유전적으로 안정성을 나타내므로 매우 효과적인 방법이다. 그러나 가금에서는 초기 배발달에 의한 급격한 세포의 수적 증가로 인해 고감염성의 virus의 획득이 요구되므로, 이를 위하여 virus stock의 농축에 있어 보다 안정적이고 pantropic인 vesicular stomatitis virus (VSV G) glycoprotein를 envelope로 가지는 pseudotyped retrovirus vector system을 이용하였으며, marker gene으로 eGFP gene이 발현되는 retrovirus를 생산하였다. 이 virus를 이용하여 여러 가지 표적세포와 primary culture한 CEF세포를 감염시켜 GFP의 발현을 확인하였으며, 농축한 virus stock은 stage X의 계란을 선택하여 windowed egg를 제작한 후 배하층에 주입하였다. 형질전환 닭은 정상 발생한 닭에 비하여 저조한 발생율을 보였으나 PCR을 이용하여 외래 유전자의 도입을 확인한 결과 100%인 것으로 나타났다. 또한 한 개체 내에서 유전자의 도입이 폐, 간, 정소, 소장 등의 여러 장기에서 확인되었다.

• Journal of Microbiology and Biotechnology
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• 제10권3호
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• pp.355-362
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• 2000

The Herpes simplex virus type 1 (HSV-1) glycoprotein B (gB) gene in the pHLA-21 plasmid was inserted into a baculovirus (Hyphantria cunea nuclear polyhedrosis virus) expression vector (lacZ-HcNPV) to construct a recombinant virus gB-HcNPV expressing gB. Spodoptera frugiperda cells infected with this recombinant virus synthesized and processed gB of approximately 120 kDa, which cross-reacted with the monoclonal antibody to gB. The recombinant gB was identified on the membrane of the insect cells using an immunofluorescence assay. Antibodies to this recombinant raised in mice recognize the viral gB and neutralized the infectivity of the HSV-1 in vitro. These results show that the gB gene has the potential to be expressed in insect cells. They also demonstrate that it is possible to produce a mature protein by gene transfer in eukaryotic cells, and indicate the utility of the lacZ-HcNPV-insect cell system for producing and characterizing eukaryotic proteins. Furthermore, the neutralizing antibodies would appear to protect mice against HSV. Accordingly, this particular recombinant protein may be useful in the development of a subunit vaccine.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 제2회 추계심포지움
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• pp.143-145
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• 1994

Chimeric fusion proteins involving IgG have proven valuable in studying protein-protein interactions and may possess therapeutic applications as well. For example, three receptor subtypes for the natriuretic peptides, when fused to the Fc portion of human IgG ${\gamma}$ chain, were quantitatively and qualitatively indistinguishable from the native receptor, thus allowing detailed structure-function studies of the receptor. In an attempt to block human immunodeficiency virus infectivity with soluble derivatives of CD4, a CD4/IgG Fc chimeric molecule was shown to increase the plasma half life of soluble CD4 and possessed the added advantage of IgG Fc-mediated placental transfer. In the case of the KGFR, this approach provided a framework for dissection of its ligand binding domains and made it possible to demonstrate that high affinity binding sites for two ligands, aFGF and KGF, reside within different receptor Ig-like domains. Chimeric molecules fused to immunoglobulins would have the advantages of secretion from transfected cells as well as detection and purification from medium utilizing Staphylococcus aureus Protein A. In addition, where highly related receptors make their discrimination very hard due to the difficulties in generating specific immunochemical probes, IgG fusion protein with tailor-made specificities confers particular advantages to elucidate patterns of receptor distribution and expression. The approach described here may have general applications in defining ligand-receptor interactions as well as searching for specific agonists and antagonists of receptor function.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.143.3-144
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• 2003

A Korean isolate of Pepper mild mottle virus (PMMoV-Kr) was isolated from a diseased pepper crop in Chunchon, Korea. The isolate was biologically purified on Nicoticaa tabacum cv. Xanthi-nc by successive single local transfer steps, and propagated on N. tabacum cv. Samsun. PMMoV-Kr could systemically infect on N. glauca, N. benthmiana, N. occidentalis and Lycopersicon esculentum, which is typical of known isolates of PMMoV. PMMoV-Kr belongs to the pathotype P1,2 based on pepper-tobamoviral indicator experiments; Capsicn chinone harboring L3 gene revealed resistant (necrotic local lesion on inoculated leaf, HR) whereas L+, L1 and L2 pepper plants expressed susceptible reactions of mosaic systemic symptoms for the isolate. To confirm the pathology and delineate symptom determinant of the isolate, full-length cDNAs of PMMoV-Kr were amplified by RT-PCR with a primer set corresponding to the 5'- and 3'-ends of PMMoV. The RT-PCR molecules amplified from genome RNA of the isolate was cloned into the pUC18 vector. Full-length cDNA clones constructed under the control of the T7 RNA promoter could be successfully transcribed to produce in vitro transcript RNA. Infectivity of the capped transcripts and its progeny virus was verified by Western blot and RT-PCR analyses.

• Asian-Australasian Journal of Animal Sciences
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• 제14권2호
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• pp.163-169
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• 2001

Despite the high potency of the retrovirus vector system in gene transfer, one of the main drawbacks of has been difficulty in preparing highly concentrated virus stock. Numerous efforts to boost the virus titer have ended in unsatisfactory results mainly due to fragile property of retrovirus envelope protein. In this study, to overcome this problem, we constructed our own retrovirus vector system producing vector viruses encapsulated with VSV-G (vesicular stomatitis virus G glycoprotein). Concentration process of the virus stock by ultracentrifuge did not sacrifice the virus infectivity, resulting in more than 108 to 109 CFU (colony forming unit) per ml on most of the target cell lines tested. Application of this high-titer retrovirus vector system was tested on chicken embryos. Injection of virus stock beneath the blastoderms of pre-incubated fertilized eggs resulted in chick embryos expressing E. coli LacZ gene with 100% efficiency. Therefore, our results suggest that it is possible to transfer the foreign gene into chicken embryo using our high-titer retrovirus vector.

• BMB Reports
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• 제33권6호
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• pp.483-492
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• 2000

The Herpes simplex virus type 1 (HSV-1) strain F glycoprotein H (gH) gene in the pHLB-4 plasmid was recombinated into a baculovirus expression vector (lacZ-HcNPV) to construct a recombinant virus GH-HcNPV expressing gH. The sequences of gH and its expression were analyzed. The gH gene was located in the 6.41 kb BglII fragment. The open reading frame (ORF) of the gH gene was 2,517 bp and codes 838 amino acid residues. Insect cells infected with this recombinant virus synthesized a high level of the matured and gX-gH fusion protein with approximately 112 kDa. The fusion gH protein was localized on the membrane of the insect cells as seen by using immunofluorescence assay and accumulated in the cultured media by the SDS-PAGE and immunoprecipitation assays. The amino acid sequence presents additional characteristics compatible with the structure of a viral glycoprotein: signal peptide, putative glycosylation sites and a long C-terminal transmembrane sequence. Antibodies raised in mice to this recombinant protein recognized viral gH and neutralized the infectivity of HSV-1 in vitro. These results demonstrate that it is possible to produce a mature protein by gene transfer in eukaryotic cells, and indicate the utility of the HcNPV-insect cell system for producing and characterizing eukaryotic proteins. Furthermore, the neutralizing antibodies would appear to protect mice against HSV; accordingly, this particular recombinant protein may be useful in the development of a subunit vaccine.

• Journal of Microbiology and Biotechnology
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• 제34권4호
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• pp.804-811
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• 2024

Foamy viruses (FVs) are generally recognized as non-pathogenic, often causing asymptomatic or mild symptoms in infections. Leveraging these unique characteristics, FV vectors hold significant promise for applications in gene therapy. This study introduces a novel platform technology using a pseudo-virus with single-round infectivity. In contrast to previous vector approaches, we developed a technique employing only two vectors, pcHFV lacking Env and pCMV-Env, to introduce the desired genes into target cells. Our investigation demonstrated the efficacy of the prototype foamy virus (PFV) dual-vector system in producing viruses and delivering transgenes into host cells. To optimize viral production, we incorporated the codon-optimized Env (optEnv) gene in pCMV-Env and the Woodchuck Hepatitis Virus Posttranscriptional Regulatory Element (WPRE) at the 3' end of the transgene in the transfer vector. Consequently, the use of optEnv led to a significant enhancement in transgene expression in host cells. Additionally, the WPRE exhibited an enhancing effect. Furthermore, the introduced EGFP transgene was present in host cells for a month. In an effort to expand transgene capacity, we further streamlined the viral vector, anticipating the delivery of approximately 4.3 kbp of genes through our PFV dual-vector system. This study underscores the potential of PFVs as an alternative to lentiviruses or other retroviruses in the realm of gene therapy.

• 한국어병학회지
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• 제22권3호
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• pp.375-382
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• 2009

목적 유전자를 숙주 세포의 게놈에 삽입하거나 발현하는데 있어서, retrovirus 매개의 유전자 전달 시스템을 사용하게 되면, 복잡하고 힘든 절차를 거치게 된다. 본 연구에서는 목적 유전자의 BF-2 세포 게놈 내 삽입을 하기 위해, UV로 불활화한 어류 레트로바이러스인 SnRV를 사용한 간단한 방법에 대해 조사하였다. 우선, BF-2 세포를 사용한 transfection을 위해 Lipofectamine 2000과 Transome을 사용하여 최적 조건을 결정하였다. 0.5 $\mu\ell$ Lipofectamine 2000을 사용한 경우 0.5, 1 그리고 2 $\mu{g}$ DNA 사용에 대해 33.8, 40.6 그리고 40.2%의 transfection 효율을 보인 동시에 최소 80 % 이상의 높은 세포 생존율을 나타낸 반면, Transome을 사용한 transfection 효율은 모두 5% 이하였다. UV 처리 시간에 있어서는 5분간의 UV 처리로 SnRV의 감염성이 불활성화되는 것을 확인하였다. 다음으로 GFP 유전자의 양측에 SnRV에서 유래된 LTR 서열을 접하고 있는 cassette를 구축한 뒤 BF-2 세포에 transfection 하고, cassette 유전자의 삽입과 발현을 위해 UV로 불활화한 SnRV를 처리하였다. 그 결과 UV로 불활화한 SnRV를 1회 처리 또는 SnRV 무처리 BF-2 세포에서는 형광이 관찰되지 않았던 반면, 3회와 5회 처리한 BF-2 세포에서 형광발현이 확인되었다. 이러한 결과로, GFP 유전자가 불활화한 SnRV를 이용하여 BF-2 세포 게놈에 삽입되는 것을 확인하였다.