• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.405-408
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• 2013

Oncoprotein Bcl-3 is perceived as an unusual member of $I{\kappa}B$ family since it can both stimulate and suppress NF-${\kappa}B$ activation. Aberrant Bcl-3 results in increased cell proliferation and survival, suggesting a contribution to malignant potential and elevated levels of Bcl-3 have been observed in many HTLV-1-infected T cell lines and ATL cells. To investigate the specific roles of Bcl-3 in HTLV-1-infected cells, we knocked down Bcl-3 expression using shRNA and then examined the consequences with regard to DNA damage and cell proliferation, as well as NF-${\kappa}B$ activation. The HTLV-1 encoded protein Tax promotes Bcl-3 expression and nuclear translocation. In HTLV-1-infected cells, Bcl-3 knockdown obviously induced DNA damage. Cell growth and NF-${\kappa}B$ activation were reduced in HTLV-1-infected or Tax positive cells when Bcl-3 expression was decreased. Together, our results revealed positive roles of Bcl-3 in DNA stabilization, growth and NF-${\kappa}B$ activation in HTLV-1-infected cells.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8253-8258
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• 2016

Elevated levels of soluble CD30 (sCD30) are linked with various T-cell neoplasms. However, the relationship between sCD30 levels and the development of adult T-cell leukemia (ATL) in human T-cell leukemia virus type 1 (HTLV-1) carriers remains to be clarified. We here investigated whether plasma sCD30 is associated with risk of ATL in a nested case-control study within a cohort of HTLV-1 carriers. We compared sCD30 levels between 11 cases (i.e., HTLV-1 carriers who later progressed to ATL) and 22 age-, sex- and institution-matched control HTLV-1 carriers (i.e., those with no progression). The sCD30 concentration at baseline was significantly higher in cases than in controls (median 65.8, range 27.2-134.5 U/mL vs. median 22.2, range 8.4-63.1 U/mL, P=0.001). In the univariate logistic regression analysis, a higher sCD30 (${\geq}30.2U/mL$) was significantly associated with ATL development (odds ratio 7.88 and the 95% confidence intervals 1.35-45.8, P = 0.02). Among cases, sCD30 concentration tended to increase at the time of diagnosis of aggressive-type ATL, but the concentration was stable in those developing the smoldering-type. This suggests that sCD30 may serve as a predictive marker for the onset of aggressive-type ATL in HTLV-1 carriers.

• The Microorganisms and Industry
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• v.16 no.1
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• pp.2-6
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• 1990

이글에서는 human retrovirus인 성인 T세포 백혈병 바이러스(human T-cell leukemia virus type I : HTLV-I)을 모델로 하여 retrovirus의 구조단백질의 생합성을 조절하는 분자기구에 대해 간단히 소개하고자 한다.

• Korean Journal of Microbiology
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• v.30 no.6
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• pp.472-478
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• 1992

Synthesis of the pol gene products of HTLV-I requires rihosomes to shift frame twice in - I direction while translating genome-size mRNA. We havc made a lI1utagcni/cd RNA in which the gag and pro genes are aligned to allow synthe,.is of a largcr amount of the Gag-Pro-Pol polyproteins by a single frameshifting. Using this mutant, wc could examine the questions whether the predicted RNA secondary or tertiary structure downstream of the shift site is operative as a determinant for - I frameshifting. Deletion analysis showed that the stem-loop structure is essential for efficient frameshifting in the pro-pol overlap, but formation of a pseudoknot is less important.

• Journal of Microbiology and Biotechnology
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• v.9 no.3
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• pp.311-317
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• 1999

Human T-cell leukemia virus Type-I (HTLV-I) is etiologically associated with rare adult T-cell leukemia, a malignant T-cell disorder. cDNAs encoding p24 (gag), gp21(env), and pXII of HTLV-I were amplified by polymerase chain reaction (PCR) using the genomic DNA extracted from HUT102 cell line as a template. The amplified cDNAs were cloned into the Escherichia coli expression vectors and over-expression of the recombinant proteins were achieved by adding IPTG into the culture media in order to induce the promoter. The molecular weights of the recombinant p24, gp21, and pXII, determined by SDS-PAGE, were found to be approximately 28 kDa, 23 kDa, and 15 kDa, respectively. Reactivity of the recombinant proteins with human sera was tested by the immunoblot assay. The gp21 and p24 reacted against the sera obtained from HTLV-I-infected individuals but not against the sera obtained from normal persons. These results suggest that the recombinant proteins expressed in E. coli were recognized by antibodies in sera from HTLV-I infected patients. These recombinant proteins would be applicable for detecting the presence of antibodies against HTLV-I in human blood samples.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1219-1225
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• 2014

Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenol molecule from green tea and is known to exhibit antioxidative as well as tumor suppressing activity. In order to examine EGCG tumor invasion and suppressing activity against adult T-cell leukemia (ATL), two HTLV-1 positive leukemia cells (HuT-102 and C91-PL) were treated with non-cytotoxic concentrations of EGCG for 2 and 4 days. Proliferation was significantly inhibited by 100 ${\mu}M$ at 4 days, with low cell lysis or cytotoxicity. HTLV-1 oncoprotein (Tax) expression in HuT-102 and C91-PL cells was inhibited by 25 ${\mu}M$ and 125 ${\mu}M$ respectively. The same concentrations of EGCG inhibited NF-kB nuclearization and stimulation of matrix metalloproteinase-9 (MMP-9) expression in both cell lines. These results indicate that EGCG can inhibit proliferation and reduce the invasive potential of HTLV-1-positive leukemia cells. It apparently exerted its effects by suppressing Tax expression, manifested by inhibiting the activation of NF-kB pathway and induction of MMP-9 transcription in HTLV-1 positive cells.

• Korean Journal of Microbiology
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• v.30 no.6
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• pp.466-471
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• 1992

To determine the site at which -1 ribosomal frameshifting occurs within the gag-pro overlap of HTL V-I. DNA fragment corresponding to a portion of the gene overlap was cloned into a SP6 vector. The resultant plasmid harbors the hybrid gene consisting of a synthetic gene encoding 5 amino acids derived from chick prelysozyme including the initiator methionine plus 141 nucleotides of gag-pro overlapping region followed by Staphylococcus aurcus protein A gene fragment. In vitro transcription by SP6 RNA polymerase with this DNA template made an abundant amount of single species mRNA. Cell-free translation programmed with the RNA transcribed in vitro yielded a polypeptide of 21 kDal in size. which could be purified into homogeneity by IgG-Sepharose affinity chromatography. In vitro system described in this study must be useful for rapid purification and sequencing of the Gag-Pro transframe protein. allowing to determine the exact frameshift site on mRNA and to identify the tRNA involved in frameshifting event for the expression of pro gene.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.186-191
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• 2005

Previous studies have demonstrated that expression of galectin-3, a member of family of beta-galactoside-binding animal lectin, is associated with pathological conditions including cancer, atherosclerosis, and viral infection. An increase of this lectin has been observed after infection by Kirsten murine sarcoma, human T lymphotropic virus-l (HTLV-l), and human immunodeficiency virus-l (HIV-l). Viral transactivation protein Tax of HTLV-l mediates the increase in the lectin. In case of HIV-1, there are evidences that Tat would be related with increase in galectin-3. We investigated whether Tat directly induced galectin-3 expression in cells. We found that HIV-l tat gene activated galectin-3 promoter in RAW264.7 cells. To demonstrate direct induction of galectin-3 by HIV-l tat, we transfected the tat into a rabbit smooth muscle cell line (Rb1) and obtained RblTatCl-2, a clone of cell stably transfected with tat gene. The Rb1TatCl-2 cells exhibited activation of LTR promoter and up-regulation of galectin-3 transcript as well as protein. Our results indicate that HIV-l tat alone is sufficient to induce the expression of galectin-3. The Rb1TatCl-2 cells could be valuable for study of the effect of HIV-1 tat on expression of cellular genes.

• Genomics & Informatics
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• v.6 no.1
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• pp.54-58
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• 2008

Genotyping Tool for Viral SEQuences (GTVseq) provides scientists with the genotype information on the viral genome sequences including HIV-1, HIV-2, HBV, HCV, HTLV-1, HTLV-2, poliovirus, enterovirus, flavivirus, Hantavirus, and rotavirus. GTVseq produces alternative and additive genotype information for the query viral sequences based on two different, but related, scoring methods. The genotype information produced is reported in a graphical manner for the reference genotype matches and each graphical output is linked to the detailed sequence alignments between the query and the matched reference sequences. GTVseq also reports the potential 'repeats' and/or 'recombination' sequence region in a separated window. GTVseq does not replace completely other well-known genotyping tools such as NCBI's virus sequence genotyping tool (http://www.ncbi. nlm.nih.gov/projects/genotyping/formpage.cgi), but provides additional information useful in the confirmation or for further investigation of the genotype(s) for the newly isolated viral sequences.

• Journal of Yeungnam Medical Science
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• v.28 no.2
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• pp.187-191
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• 2011

Adult T-cell leukemia/lymphoma (ATLL) is a malignancy of mature T-cells caused by the human T-cell lymphotrophic virus type I (HTLV-D. HTLV-I is endemic in some areas in Japan, the Caribbean basin, and Africa but has low prevalence in South Korea. Patients with ATLL are susceptible to opportunistic infections such as cytomegalovirus (CMV) infection, but CMV infection in chronic ATLL is uncommon. Reported herein is a case involving a 44-year-old woman with chronic ATLL who presented the symptoms of fever and diarrhea. She was suspected to have acute-type ATLL but was later diagnosed with CMV colitis.