Expression of Dopaminergic Transcription Factor Nurr1 in Human Cells Via Recombinant Lentiviruses
Volume 7, Issue 1, Spring 2016, Pages 1-7
https://doi.org/10.52547/JCT.7.1.1
M G, A R, E E
Abstract Aim: The aim of this study was to generate recombinant lentiviruses carrying Nurr1 to express it in human cells. Material and methods: The IRES-EGFP fragment was isolated from the pIRES2-EGFP vector using restriction enzymes BglII/NotI and made blunt-ended using Klenow. The transfer vector PNL-EGFP/CMV/WPREdU3 was digested with NheI/XhoI and made blunt-ended. Finally, the isolated IRES-EGFP fragment was inserted into this lentivirus vector to generate lentivirus construct (I). The human Nurr1 gene was then isolated from the PCMX-NOT vector using BamHI and XhoI and inserted into construct (I) pre-digested with BamHI and SalI. At this step lentivirus construct (II) as our final transfer construct was generated. In order to generate recombinant lentiviruses, we then transfected the HEK-293T cell line with transfer vector plus packaging and envelope vectors. Cell medium full of virus particles was collected and passed through Amicon filters to produce a concentrated virus stock. The stock was ultimately used for transduction of fresh HEK-293T cells. EGFP expression was shown under fluorescent microscope and Nurr1 expression was analyzed using RT-PCR. Results: Enzymatic tests confirmed the correct cloning of the hNurr1gene into the lentivirus backbone. Observation by fluorescent microscopy showed EGFP expression post-transfection and post-transduction. RT-PCR demonstrated Nurr1 expression at both stages. Conclusion: In this study, lentiviruses carrying the human Nurr1 gene were produced and used for transduction of human cell line HEK-293T. The transduced cells successfully expressed the Nurr1 gene.
Inducible Gene Expression of GFP Reporter Gene in LMH Cell Line Using Inducible Lentivirus Vectors
Volume 6, Issue 3, Winter 2016, Pages 241-248
https://doi.org/10.52547/JCT.6.3.241
A R, M G, E S
Abstract Aim: By combining Tet-inducible system and lentivirus vectors, we investigated the induction of Enhanced Green Fluorescent Protein (EGFP) reporter gene in poultry cells. Material and Methods: the EGFP gene was placed under Tet-ON system and its induction was studied in liver cell line LMH. First, we transformed competent bacteria separately with an inducible lentivirus vector carrying EGFP and a second vector carrying Tet transactivator rtTA-M2 and prepared a purified maxi-prep stock of either plasmid DNA. Then, we used DNA-calcium phosphate co-precipitation method to co-transfect LMH cells with both plasmid stocks. In the next step, we added different concentrations of Tet analog doxycycline (DOX) to cell growth medium. Results: Increase of DOX concentration caused elevation of gene expression Within the first 24 hours after post-transfection, the expression of EGFP for 0, 0.01, 0.1 and 1 µg/ml of DOX was 0.4, 6.2, 10.3 and 16% respectively, and in the next 24 hours the expression changed to 6.4, 26, 28.3 and 29.7% respectively. However, treatment with the overdose of DOX caused the cell death. Conclusions: Combination of Tet-inducible system originating from bacteria and recombinant lentivirus vectors designed for gene transfer to human cells can jointly promote transgene expression in poultry cells. The concentration of the inducer can directly influence the level of transgene induction.