• Nuclear Medicine and Molecular Imaging
• /
• v.42 no.5
• /
• pp.394-400
• /
• 2008

Purpose: Quantitative comparison of transgene expression within stem cells between lentivirus and adenovirus-mediated delivery systems has not been reported. Here, we evaluated the human sodium iodide symporter (hNIS) gene expression in rat mesenchymal stem cell (rMSC) transduced by lentivirus or adenovirus, and compared the hNIS expression quantitatively between the two delivery systems. Materials and Methods: Lentiviral-mediated hNIS expressing rMSC (lenti-hNIS-rMSC) was constructed by cloning hNIS gene into pLenti6/UbC/V5-DEST (Invitrogen) to obtain pLenti-hNIS, transducing rMSC with the pLenti-hNIS, and selecting with blasticidin for 3 weeks. Recombinant adenovirus expressing hNIS gene (Rad-hNIS) was produced by homologous recombination and transduction efficiency of Rad-hNIS into rMSC evaluated by Rad-GFP was $19.1{\pm}4.7%$, $54.0{\pm}6.4%$, $85.7{\pm}8.7%$, and $98.4{\pm}1.3%$ at MOI 1, 5, 20, and 100, respectively. The hNIS expressions in lenti-hNIS-rMSC or adeno-hNIS-rMSC were assessed by immunocytochemistry, western blot, and 1-125 uptake. Results: Immunocytochemistry and western blot analyses revealed that hNIS expressions in lenti-hNIS-rMSC were greater than those in adeno-hNIS-rMSC at MOI 20 but lower than at MOI 50. However in vitro 1-125 uptake test demonstrated that iodide uptake in lenti-hNIS-rMSC ($29,704{\pm}6,659\; picomole/10^6\;cells$) was greater than that in adeno-hNIS-rMSC at MOI 100 ($6,168{\pm}2,134\;picomole/10^6\;cells$). Conclusion: Despite lower amount of expressed protein, hNIS function in rMSC was greater by lentivirus than by adenovirus mediated expression. Stem cell tracking using hNIS as a reporter gene should be conducted in consideration of relative vector efficiency for transgene expression.

• Korean Journal of Poultry Science
• /
• v.35 no.3
• /
• pp.241-245
• /
• 2008

Lentiviral vector system is efficient vehicles for the delivery of exogenous genes, and it is generally used in the generation of transgenic chickens. In this study, we used recombinant lentiviral vectors to generate transgenic chicks that express the human superoxide dismutase-3 gene driven by the chicken ovalbumin promoter. It is well known that superoxide dismutases(SODs) are believed to play a crucial role in protecting cells against oxygen toxicity. There are three forms of SOD proteins: cytosolic Cu-Zn SOD, mitochondrial Mn SOD, and extracellular SOD(SOD-3). The recombinant lentivirus containing the human SOD-3 gene was injected into the subgerminal cavity of freshly laid eggs. Subsequently, the embryos were incubated to hatch using phases II and III of the surrogate shell ex vivo culture system. From 341 injected embryos, the 78 chicks hatched after 21 days incubation. The hatched chicks were screened for the human SOD-3 gene by using PCR. Two of 47 male chickens that survived to sexual maturity contained the human SOD-3 gene in their semen. These results showed that our transgenic chicken generation system was completely established.

• Journal of Marine Bioscience and Biotechnology
• /
• v.2 no.2
• /
• pp.81-85
• /
• 2007

Glucocorticoid hormone regulates numerous physiological processes, such as regulation of metabolism, and anti-inflammatory and immunosuppressive actions via the activation and repression of gene expression. Here we described a lentivirus-based reporter vector system expressing red fluorescent protein (mRFP) or firefly luciferase (Luc) under the control of a glucocorticoid-responsive element that allows observation of the temporospatial pattern of glucocorticoid induced GR-mediated signaling on a cellular level. Moreover, usage of the chromatin insulator of the chicken ${\beta}$-globin locus induced a marked increase of sensitivity of glucocorticoid inducible promoter of a reporter gene. Use of this method will be applicable of screening for agonist and antagonist of GR in vitro, and also a reporter gene assay for the in vivo determination of the GR-mediated gene activation.

• Clinical and Experimental Reproductive Medicine
• /
• v.36 no.4
• /
• pp.283-292
• /
• 2009

Objective: Human embryonic stem cells (hESCs) can proliferate indefinitely and differentiate into all kinds of cell types in vitro. Therefore, hESCs can be used as a cell source for cell-based therapy. Transduction of foreign genes to hESCs could be useful for tracing differentiation processes of hESCs and elucidation of gene function. Thus, we tried to introduce enhanced green fluorescent protein (eGFP) gene to hESCs, XX and XY cell lines in this study. Methods: Lentivirus containing eGFP was packaged in 293T cells and applied to hESCs to transduce eGFP. Expression of transduced eGFP was evaluated under the fluorescence microscope and eGFP positive population was analyzed by FACS. Expression of undifferentiation state markers such as Oct4, Nanog, SSEA4 and Tra-1-81 was examined by RT-PCR and/or immunofluorescence in eGFP-hESCs after transduction. In addition, the ability of eGFP-hESCs to form embryoid bodies (EBs) was tested. Results: eGFP was successfully transduced to hESCs by lentivirus. eGFP expression was stably maintained up to more than 40 passages. eGFP-hESCs retained expression patterns of undifferentiation state markers after transduction. Interestingly, disappearance of transduced eGFP was notably observed during spontaneous differentiation of eGFP-hESCs. Conclusion: We established eGFP expressing hESC lines using lentivirus and showed the maintenance of undifferentiation characteristics of these eGFP-hESCs. This reporter-containing hESCs could be useful for tracing the processes of differentiation of hESCs and other studies.

• Biomedical Science Letters
• /
• v.5 no.1
• /
• pp.101-107
• /
• 1999

Bovine immunodeficiency virus (BIV) which was grouped into the Lentivirinae of family Retroviridae, was known to be causing many immunodeficiency syndromes among cows. The BIV was studied worldwide during last several years for its importance in cattle industries but nothing was reported in Korea until now Thus we initially tried to study the existence of BIV in cattle around the Daegu·Kyungpook area by PCR related molecular techniques. As a prerequisite investigation for detecting Korean-type BIV, we had focused our aim into BLV infected cows because the BLV infected cows tend to show BIV infection with 5％ ranges. Hence we randomly sampled fresh bloods from 248 cows and bulls near the Daegu·Kyungpook area and collected peripheral blood monocytes (PBMC) from the sample bloods. After extracting genomic DNA from the PBMC, we subjected it to PCR and Soluthern blot analysis for BIV/BLV detection. Overall, 66.9% (81/121) of the cow PBMC samples turned out to be BLV positive by PCR and the result was reconfirmed by Southern blot analysis. The value was two times higher than the previously reported results of BLV infection in Korea. The significant difference was mainly due to 1) applying highly specific methods for BLV detection such as PCR 2) that BLV was continuously spreaded in the Daegu Kyungpook area without any notice during last ten years. We also tested the BLV positive samples with the same techniques for BIV detection. And we found some BIV positives among the lot 3C samples by PCR, which had showed 100% BLV positive.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2006.11a
• /
• pp.80-81
• /
• 2006

닭의 유전자 지도가 밝혀지고 그와 관련한 생물학적 연구들이 활발히 이루어지면서 닭을 생체 반응기나 질병 모델 동물로 이용하기 위한 연구가 많이 진행되고 있다. 이 중 닭을 생체 반응기로 이용하기 위해서는 많은 양의 단백질을 생산하는 난관에 대한 연구가 필수적이다. In vivo와 in vitro에서 난관 특이적 프로모터에 의한 외래 유전자의 발현에 대한 연구를 하였고 유전자를 전이하는 방법으로는 렌티 바이러스 시스템을 이용하였으며, 프로모터는 난관 특이적 프로모터인 오브알부민 프로모터 (5‘ 조절 부분의 1.4kb)와 RSV 프로모터를 이용하였다. 리포터 유전자로는 형광발현 단백질 (enhanced green fluorescence protein, EGFP)을 이용해서 마우스 배아 섬유아세포, 닭 배아 섬유아세포, 난관 상피 세포에서 발현을 유도해서 조직 특이적 발현 여부를 확인하였다. 그 결과 RSV 프로모터는 모든 세포에서 발현하였으나, 오브알부민 프로모터에 의한 리포터 유전자의 발현은 난관 상피 세포에서는 특이적으로 발현하였다. 이와 같은 연구는 산란계를 이용해서 난관으로부터 효율적인 생리 활성 물질을 생산하기 위한 가능성을 보여주었다.

• YAKHAK HOEJI
• /
• v.49 no.3
• /
• pp.217-224
• /
• 2005

Human Immunodeficiency Virus type 1 (HIV-l) based lentivirus vector has demonstrated great potential as gene therapy vectors mediating efficient gene delivery and long-term transgene expression in both dividing and nondividing cells. However, for clinical studies it must be confirmed that vector preparations are safe and not contaminated by replication competent lentivirus (RCL) related to the parental pathogenic virus, HIV-l. In this study, we would like to establish the method for titration and RCL detection of lentivirus vector. The titration was determined by vector expression containing the green fluorescent protein, GFP in transduced cells. The titer was $1{\times}10^7$ Transducing Unit/ml in the GFP expression assay and $8.9{\times}10^7$ molecules/ml in the real-time PCR. Also, for the detection of RCL, we have used a combination method of PCR and p24 antigen detection. First, PBS/psi and VSV-G region in the genomic DNA of transduced cells was detected by PCR assay. Second, transfer and expression of the HIV-1 gag gene was detected by p24 ELISA. In an attempt to amplify any RCL, the transduced cells were cultured for 3 weeks (amplification phase) and the supernatant of amplified transduced cell was used for the second transduction to determine whether a true RCL was present (indicator phase). Analysis of cells and supernatant at day 6 in indicator phase were negative for PBS/psi, VSV-G, and p24 antigen. These results suggest that they are not mobilized and therefore there are no RCL in amplification phase. Thus, real-time PCR is a reliable and sensitive method for titration and RCL detection of lentivirus vector.

• Investigative Magnetic Resonance Imaging
• /
• v.16 no.1
• /
• pp.47-54
• /
• 2012

Purpose : This study was performed to evaluate the characteristics of rat mesenchymal stem cells (RMSCs) transduced with human ferritin gene and investigate $in$ $vitro$ MRI detectability of ferritin-transduced RMSCs. Materials and Methods: The RMSCs expressing both myc-tagged human ferritin heavy chain subunit (myc-FTH) and green fluorescence protein (GFP) were transduced with lentiviurs. Transduced cells were sorted by GFP expression using a fluorescence-activated cell sorter. Myc-FTH and GFP expression in transduced cells were detected by immunofluorescence staining. The cell proliferative ability and viability were assessed by MTT assay. The RMSC surface markers (CD29+/CD45-) were analyzed by flow cytometry. The intracellular iron amount was measured spectrophotometically and the presence of ferritin-iron accumulation was detected by Prussian blue staining. $In$ $vitro$ magnetic resonance imaging (MRI) study of cell phantoms was done on 9.4 T MR scanner to evaluate the feasibility of imaging the ferritin-transduced RMSCs. Results: The myc-FTH and GFP genes were stably transduced into RMSCs. No significant differences were observed in terms of biologic properties in transduced RMSCs compared with non-transduced RMSCs. Ferritin-transduced RMSCs exhibited increased iron accumulation ability and showed significantly lower $T_2$ relaxation time than non-transduced RMSCs. Conclusion: Ferritin gene as MR reporter gene could be used for non-invasive tracking and visualization of therapeutic mesenchymal stem cells by MRI.