• 농업과학연구
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• 제38권2호
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• pp.249-255
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• 2011

This study was performed to investigate the characterization of infectious BLV env gene isolated form Korean Holstein Cattle and to determine its incoming origin. Gp51 region of BLV env gene known as having important role in immunological function was characterized using PCR-RFLP sequencing and phylogenetic analysis. BLV env gene was grouped into PCR-RFLP patterns with three restriction endonucleases including Pvu II, BamHI and Hae III, and we identified two new RFLP patterns from nucleotide sequences of each group. Phylogenetic analysis showed that 80% of the Korean Holstein was included in the USA and Japanese group. These results here can provide a valuable information about the character of the BLV env gene and research on infection route of BLV.

• 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.

• 대한수의학회지
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• 제55권1호
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• pp.53-56
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• 2015

Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis. This study was conducted to clarify the molecular characteristics of BLVs obtained from a specific region in Korea. Proviral BLVs were detected in anti-BLV antibody-positive blood samples by PCR. Env and gag fragments were sequenced and compared to previously published reference sequences. Analysis of the env gene sequence revealed that the YI strain was highly similar to genotype 1, including United States and Japanese strains. The gag gene sequence had the highest degree of similarity with a Japanese strain.

• Journal of Microbiology and Biotechnology
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• 제34권2호
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• pp.280-288
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• 2024

The fusogenic membrane glycoprotein (FMG) derived from the human endogenous retrovirus-W (HERV-W) exhibits fusogenic properties, making it a promising candidate for cancer gene therapy. When cells are transfected with HERV-W FMG, they can fuse with neighboring cells expressing the receptor, resulting in the formation of syncytia. These syncytia eventually undergo cell death within a few days. In addition, it has been observed that an HERV-W env mutant, which is truncated after amino acid 483, displays increased fusogenicity compared to the wild-type HERV-W env. In this study, we observed syncytium formation upon transfection of HeLa and TE671 human cancer cells with plasmids containing the HERV-W 483 gene. To explore the potential of a semi-replication-competent retroviral (s-RCR) vector encoding HERV-W 483 for FMG-mediated cancer gene therapy, we developed two replication-defective retroviral vectors: a gag-pol vector encoding HERV-W 483 (MoMLV-HERV-W 483) and an env vector encoding VSV-G (pCLXSN-VSV-G-EGFP). When MoMLV-HERV-W 483 and pCLXSN-VSV-G-EGFP were co-transfected into HEK293T cells to produce the s-RCR vector, gradual syncytium formation was observed. However, the titers of the s-RCR virus remained consistently low. To enhance gene transfer efficiency, we constructed an RCR vector encoding HERV-W 483 (MoMLV-10A1-HERV-W 483), which demonstrated replication ability in HEK293T cells. Infection of A549 and HT1080 human cancer cell lines with this RCR vector induced syncytium formation and subsequent cell death. Consequently, both the s-RCR vector and RCR encoding HERV-W 483 hold promise as valuable tools for cancer gene therapy.

• Molecules and Cells
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• 제28권2호
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• pp.99-103
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• 2009

Human endogenous retroviruses (HERVs) have been implicated in the pathogenesis of several human diseases as multi-copy members in the human genome. Their gene expression profiling could provide us with important insights into the pathogenic relationship between HERVs and cancer. In this study, we have evaluated the genomic structure and quantitatively determined the expression patterns in the env gene of a variety of HERV family members located on six specific loci by the RetroTector 10 program, as well as real-time RT-PCR amplification. The env gene transcripts evidenced significant differences in the human tumor/normal adjacent tissues (colon, liver, uterus, lung and testis). As compared to the adjacent normal tissues, high levels of expression were noted in testis tumor tissues for HERV-K, in liver and lung tumor tissues for HERV-R, in liver, lung, and testis tumor tissues for HERV-H, and in colon and liver tumor tissues for HERV-P. These data warrant further studies with larger groups of patients to develop biomarkers for specific human cancers.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1999년도 춘계학술발표대회:발표논문요지록
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• pp.16-16
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• 1999

• Genomics & Informatics
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• 제3권4호
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• pp.133-141
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• 2005

Most of the endogenous retroviral genes integrated into the primate genome after the split of New World monkeys in the Oligocene era, approximately 33 million years ago. Because they can change the structure of adjacent genes and move between and within chromosomes they may play important roles in evolutionas well as in many kinds of disease and the creation of genetic polymorphism. Comparative analysis of HERVs (human endogenous retroviruses) and their LTR (long terminal repeat) elements in the primate genomes will help us to understand the possible impact of HERV elements in the evolution and phylogeny of primates. For example, HERV-K LTR and SINE-R elements have been identified that have been subject to recent change in the course of primate evolution. They are specific elements to the human genome and could be related to biological function. The HERV-M element is related to the superfamily of HERV-K and is integrated into the periphilin gene as the truncated form, 5'LTR-gag-pol-3'LTR. PCR and RT-PCR approaches indicated that the insertion of various retrotransposable elements in a common ancestor genome may make different transcript variants in different primate species. Examination of the HERV-W elementrevealed that env fragments were detected on human chromosomes 1, 3-7, 12, 14, 17, 20, and X, whilst the pol fragments were detected on human chromosomes 2-8, 10-15, 20, 21, X, and Y. Bioinformatic blast search showed that almost full-length of the HERV-W family was identified on human chromosomes 1-8, 11-15, 17, 18, 21, and X. Expression analysis of HERV-W genes (gag, pol, and env) in human tissues by RT-PCR indicated that gag and pol were expressed in specific tissues, whilst env was constituitively expressed in all tissues examined. DNA sequence based phylogenetic analysis indicated that the gag, pol and env genes have evolved independently during primate evolution. It will thus be of considerable interest to expand the current HERV gene information of various primates and disease tissues.

• 미생물학회지
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• 제21권2호
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• pp.61-70
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• 1983

Synchronized cat kidney cells chronically infected with feline leukemia virus (FeLV) were used to study virus production, the synthesis of group specific antigen (gag) and envelope (env) proteins, the expression of env protein on the cell surface during the cell cycle, and the stability of viral RNA. As detecting method, we developed the radioimmunoassay (RIA) system using beta-emission of $^{131}I$ and demonstrated the validity of this system by comparison with routine RIA system using gamma-emission of $^{125}I$. The produced virus was analysed by developed RIA interval was determined by measuring reverse transcriptase activity. The results show that infected cells produce the complete virus particle containing products of gag, env and pol genes of FeLV, and maximum virus production occurs during mitosis of synchronized cells. Labeling of the cell surface of synchronized cells with $^{131}I$ shows that the amount of $gp70^{env}$ on the cell surface parallels cellular gorwth. Therefore, the cell cycle-dependent release of virus is not petition RIA of synchronized cells with $^{131}I$ labeled viral proteins synthesis during the cell cycle. The rate of synthesis of gag protein shows three peaks, corresponding to the $G_1,\;late\;S\;and\;late\;G_2$ phases of cell cycle. But the rate of synthesis of env protein dose not change, suggesting that in these cells the synthesis of these two gene products in controlled seperately. In Actionomycin D treated cells, the synthesis of viral proteins decreased sharply from 8 hours after treatment, and the late S and $G_2$ peaks of gag protein synthesis were disappeared. This shows the stability of viral RNA for about 6 hours in the absence of continuing viral RNA synthesis.

• Journal of Microbiology and Biotechnology
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• 제18권10호
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• pp.1735-1740
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• 2008

Clone PERV-C (A3) env was isolated from the genomic DNA of domestic pig (Sus scrofa domesticus) in Korea to investigate the molecular properties of PERV-C. The nucleic acid homologies between the PERV-MSL (type C) reference and the PERV-C(A3) clone was 99% for env, but a single base pair deletion was found in the transmembrane (TM) region of the env open reading frame. To examine the functional characteristics of truncated PERV-C env, we constructed a replication-incompetent retroviral vector by replacing the env gene of the pCL-Eco retrovirus vector with PERV-C env. A retroviral vector bearing PERV-C/A chimeric envelopes was also created to complement the TM defect. Our results indicated that truncated PERV-C env was not infectious in human cells as expected. Interestingly, however, the vector with the PERV-C/A envelope was able to infect 293 cells. This observation suggests that recombination within PERV-C TM could render PERV-C infectious in humans. To further characterize PERV-C/A envelopes, we constructed an infectious molecular clone by using a PCR-based technique. This infectious molecular clone will be useful to examine more specific regions that are critical for human cell tropism.

• 미생물학회지
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• 제43권2호
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• pp.91-99
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• 2007

인간면역결핍바이러스(Human immunodeficiency virus; HIV) 진단을 위한 다중, 초고속실시간 PCR법을 개발하였다. 검출대상의 DNA 염기서열은 env 유전자를 기반으로 설계되었으며, 각기 HIV-1 특이 495염기(gi_1184090) 및 HIV-2 특이 294염기(gi_1332355)의 DNA를 안정상의 이유로 PCR을 이용한 유전자합성법으로 제작하여 사용하였다. 초고속 실시간 PCR은, PCR의 회전 중 각 단계별 설정시간을 극단적으로 축소하여, $1\;{\mu}l$의 PCR 용액용 microchip을 탑재할 수 있는 $Genspector^{TM}$을 사용하여 수행하였다. DNA 증폭과 융점분석을 포함한 총 PCR 검색 시간은 HIV_1 및 HIV-2 모두에서 15분 이내로 완료되었으며, 각기 최소 2.3개의 합성 env 유전자로부터도 HIV-1 특이 117염기와 HIV-2 특이 119염기의 PCR산물을 성공적으로 증폭시킬 수 있는 민감성을 보여주었다. 이런 형식의 실시간 PCR법을 본 연구에서 초고속실시간 PCR (Ultra-rapid real-time PCR)이라 명명하였다. 이는 본 연구의 대상인 HIV에 대한 보조적 진단방법일 뿐 아니라 PCR 검색법이 사용되고 있는 다른 병원체에 대하여도 적용될 수 있을 것이나, 우선 HIV 임상시료에 대한 본 검색법의 효용성 실험 등 추가 연구가 필요할 것으로 사료된다.