• Molecules and Cells
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• v.19 no.2
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• pp.191-197
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• 2005

The human immunodeficiency virus type 1 (HIV-1) Tat protein transduction domain (PTD) is responsible for highly efficient protein transduction across plasma membranes. In a previous study, we showed that Tat-Cu,Zn-superoxide dismutase (Tat-SOD) can be directly transduced into mammalian cells across the lipid membrane barrier. In this study, we fused the human SOD gene with a Tat PTD transduction vector at its N- and/or C-terminus. The fusion proteins (Tat-SOD, SOD-Tat, Tat-SOD-Tat) were purified from Escherichia coli and their ability to enter cells in vitro and in vivo compared by Western blotting and immunohistochemistry. The transduction efficiencies and biological activities of the SOD fusion protein with the Tat PTD at either terminus were equivalent and lower than the fusion protein with the Tat PTD at both termini. The availability of a more efficient SOD fusion protein provides a powerful vehicle for therapy in human diseases related to this anti-oxidant enzyme and to reactive oxygen species.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.77-77
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• 1995

Human immunodeficiency virus type 1 (HIV-1) contains several nonstructural genes which are required for the viral replication and disease pathogenesis. Among them, tat and nef genes encode an essential transactivator of HIV-1 LTR and a pluripotent protein which seems to be essential for the in vivo but not in vitro viral replication, respectively. We constructed two tat and n of defective HIV-1 and tested for their ability to replicate in several T cells. The defective viruses did not replicate in CD4$\^$+/ T cells, but rescued in the recombinant Jurkat-tat cell which also contains tat gene. The replication of tat and nef defective HIV-1 which expresses chloramphenicol acetyltransferase(CAT) gene was easily detected by a sensitive CAT assay. No revertant was identified during the passages of the mutant viruses for more than two months in Jurkat-tat cells. tat and n of defective HIV-1 could be used instead of wild type viruse for several purposes such as inhibitor screening and development of attenuated AIDS vaccine.

• BMB Reports
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• v.51 no.8
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• pp.394-399
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• 2018

Human immunodeficiency virus-1 (HIV-1) transactivator of transcription (Tat) is an important viral factor in neuro-inflammation. Hindsiipropane B, present in Celastrus hindsii, possesses various biological mechanisms including anti-inflammatory activity. In this report, we explored the regulatory activity of hindsiipropane B on HIV-1 Tat-mediated chemokine production and its mode of action in astrocytes. Hindsiipropane B significantly alleviated HIV-1 Tat-mediated production of inflammatory chemokines, CCL2, CXCL8, and CXCL10. Hindsiipropane B inhibited expression of HDAC6, which is important regulator in HIV-1 Tat-mediated chemokine production. Hindsiipropane B diminished HIV-1 Tat-mediated reactive oxygen species (ROS) generation and NADPH oxidase activation/expression. Furthermore, hindsiipropane B inhibited HIV-1 Tat-mediated signaling cascades including MAPK, $NF-{\kappa}B$, and AP-1. These data suggest that hindsiipropane B exerts its inhibitory effects on HIV-1 Tat-mediated chemokine production via down-regulating the HDAC6-NADPH oxidaseMAPK-$NF-{\kappa}B$/AP-1 signaling axis, and could serve as a therapeutic lead compound against HIV-1 Tat-associated neuro-inflammation.

• Molecules and Cells
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• v.21 no.1
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• pp.104-111
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• 2006

Gene therapy with nonviral vectors using the suicide gene/prodrug activating system of herpes simplex virus type-1 thymidine kinase (HSV1-TK)/ganciclovir (GCV) is inefficient in killing malignant tumor cells due to two major factors: (a) an unsatisfactory bystander effect; (b) short-lived expression of the protein. To study the capacity of the protein transduction domain (PTD) of HIV-1 TAT protein to enhance HSV1-TK/GCV cancer gene therapy, we constructed three fusion proteins TAT-TK, TK-TAT and TK. TAT-TK retained as much enzyme activity as TK, whereas that of TK-TAT was much lower. TAT-TK can enter HepG2 cells and much of it is translocated to the nucleus. The transduced HepG2 cells are killed by exogenously added GCV and have bystander effects on untransduced HepG2 cells. Most importantly, the introduced recombinant protein is stable and remains functional for several days at least, probably because nuclear localization protects it from the cytoplasmic degradation machinery and provides access to the nuclear transcription machinery. Our results indicate that TAT fusion proteins traffic intercellularly and have enhanced stability and prodrug cell killing activity. We conclude that TAT has potential for enhancing enzyme prodrug treatment of liver cancers.

• Journal of Korean Clinical Nursing Research
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• v.24 no.2
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• pp.227-234
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• 2018

Purpose: This study compared the temporal artery temperature (TAT) measured by infrared temporal artery thermometers to the axillary temperature (AT) measured by standard mercury-in-glass thermometers, and evaluated accuracy of the TAT measurement for clinical practice. Methods: A total of 247 adult inpatients in general wards in a tertiary medical center located in Seoul participated in the study. The TAT was measured within one minute after the AT measurement. Data were analyzed using descriptive statistics, paired t-test, Pearson correlation coefficient, linear regression, and the Bland-Altman plot. Results: There was a significant difference in mean temperature between AT and TAT, $36.89^{\circ}C$ (SD=0.70) versus $37.35^{\circ}C$ (SD=0.72). The Bland-Altman plots demonstrated the difference between the AT and TAT as -1.29 to +0.33. The specificity and sensitivity of the TAT in detecting fever were high. The positive predictive values were 57.5% and 71.0% when the AT were higher than $38.0^{\circ}C$ and the TAT fever cutoff levels were $38.0^{\circ}C$ and $38.3^{\circ}C$ respectively. Conclusion: TAT and AT were highly correlated and agreeable, indicating that TAT is as accurate as AT. The findings suggested that TAT measurement can be used in clinical practice. For accurate communication between medical personnel, medical institutions need to provide guidelines for temperature measurement, especially for the use of thermometer and measurement sites.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1103-1108
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• 2009

The human immunodeficiency virus (HIV)-l protein Tat acts as a transcription transactivator that stimulates expression of the infected viral genome. It is released from infected cells and can similarly affect neighboring cells. The nucleocapsid is an important protein that has a related significant role in early mRNA expression, and which contributes to the rapid viral replication that occurs during HIV-1 infection. To investigate the interaction between the Tat and nucleocapsid proteins, we utilized cDNA micro arrays using pTat and flag NC cotransfection in HEK 293T cells and reverse transcription-polymerase chain reaction to validate the micro array data. Four upregulated genes and nine downregulated genes were selected as candidate genes. Gene ontology analysis was conducted to define the biological process of the input genes. A proteomic approach using PathwayStudio determined the relationship between Tat and nucleocapsid; two automatically built pathways represented the interactions between the upregulated and downregulated genes. The results indicate that the up- and downregulated genes regulate HIV-1 replication and proliferation, and viral entry.

• Journal of Microbiology and Biotechnology
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• v.25 no.6
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• pp.788-794
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• 2015

Cationic liposomes have been actively used as gene delivery vehicles despite their unsatisfactory efficiencies because of their relatively low toxicity. In this study, we designed novel heterodimeric peptides as nonviral gene delivery systems from TAT and NLS peptides using cysteine-to-cysteine disulfide bonds between the two. Mixing these heterodimeric peptides with DNA before mixing with lipofectamine resulted in higher transfection efficiencies in MCF-7 breast cancer cells than mixing unmodified TAT, NLS, and a simple mixture of TAT and NLS with DNA, but did not show an adverse effect on cell viability. In gel retardation assays, the DNA binding affinities of heterodimeric peptides were stronger than NLS but weaker than TAT. However, this enhancement was only observed when heterodimeric peptides were premixed with DNA before being mixed with lipofectamine. The described novel transfection-enhancing peptide system produced by the heterodimerization of TAT and NLS peptides followed by simple mixing with DNA, increased the gene transfer efficiency of cationic lipids without enhancing cytotoxicity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.475-476
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• 2019

L-shaped tunneling field-effect-transistor (LTFET) is considered a superior device over conventional TFETs. However, experimentally demonstrated LTFET demonstrated poor subthreshold characteristics which was attributed to trap-assisted-tunneling (TAT) caused by presence of trap states. In this paper, TAT mechanism in the experimentally demonstrated LTFET is investigated with the help of band diagram and TAT recombination rate (GTAT).

• Proceedings of the Korea Society of Design Studies Conference
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• 2002.05b
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• pp.88-89
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• 2002

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.3
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• pp.163-168
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• 2003

The reactive oxygen species (ROS) are considered to be an important mediator in pancreatic ${\beta}$ cell destruction, thereby triggering the development of insulin-dependent diabetes mellitus. In the present study, HIV-1 Tat-mediated transduction of Cu,Zn-superoxide dismutase (SOD) was investigated to evaluate its protective potential against streptozotocin (STZ)-induced cytotoxicity in insulin-producing MIN6N cells. Tat-SOD fusion protein was successfully delivered into MIN6N cells in a dose-dependent manner and the transduced fusion protein was enzymatically active for 48 h. The STZ induced-cell destruction, superoxide anion radical production, and DNA fragmentation of MIN6N cells were significantly decreased in the cells pretreated with Tat-SOD for 1 h. Furthermore, the transduction of Tat-SOD increased Bcl-2 and heat shock protein 70 (hsp70) expressions in cells exposed to STZ, which might be partly responsible for the effect of Tat-SOD. These results suggest that an increased of free radical scavenging activity by transduction of Tat-SOD enhanced the tolerance of the cell against oxidative stress in STZ-treated MIN6N cells. Therefore, this Tat-SOD transduction technique may provide a new strategy to protect the pancreatic ${\beta}$ cell destruction in ROS-mediated diabetes.