Objective To explore the effect of HTLV-1 (human T-cell leukemia virus type 1 ) Tax protein on the DcR3 gene expression in T cells.Methods The construction of DcR3 (-1010 bp to +114 bp) luciferase reporter gene; MT2,TaxP,and Jurkat E6-1 cells were transfected with DcR3 luciferase reporter gene (pGL3-DcR3-1uc) using liposomes according to the manufacturer's instructions.For the control group,pGL3-basic replaced it respectively.At 48 h after incubation,luciferase activity was measured with a luciferase assay system; Jurkat cells were transfected with pCMV-Tax-Bam using liposomes,and total RNA was extracted from the cells at 48 h after incubation.Reverse transcription was performed using standard protocols.Then real time PCR with primers DcR3 and 3-actin was conducted;The expression of DcR3 protein was detected by flow cytometry in MT2,TaxP,and Jurkat cells.Results The construction of DcR3 luciferase reporter gene is identified correctly; The detection of luciferase activity showed that the luciferase activity of experimental group in MT2 cells was increased by (32.07±12.43)-fold,of which in TaxP cells was increased by ( 13.27±4.04)-fold,and the luciferase activity of experimental group in Jurkat cells was increased by ( 1.26±0.49 ) -fold.And there is statistic significance about the relative luciferase activity of experimental group in MT2 cells and TaxP cells compared to the relative lueiferase activity of experimental group in Jurkat cells respectively ( P＜0.01 ) ; The result of real-time PCR showed that the level of DcR3 mRNA in the experimental group was higher compared with the control group(P＜0.05) ; The result of FCM shows the expression of DcR3 protein in MT2,TaxP cells is higher than that in Jurkat cells( P＜0.05 ).Conclusion Tax protein can promote the expression of DcR3 gene in T cells.

Objective To study the effects of the adult T cell leukemia virus type 1(HTLV-1) Tax protein on T lymphocytes self-reactive growth hormone(GH). Methods The expression of the growth hormone protein was measured by Western blot in TaxP and TaxN cells, which expresses HTLV-1 Tax or no. The location of growth hormone in the TaxP and TaxN cells were detected by LSCM(laser scanning confocal microscope). The level of growth hormone mRNA in TaxP and TaxN cells was measured by RT-PCR. The pGL2-GH-luc was transfected in TaxN and TaxP cells by Tfx-50-mediated transfection to assay transcriptional activity. The pNF-κB-luc, pAP-1-luc and pNFAT-luc was transfected into TaxP cells with pcDNA3.0-GH by Tfx50 to test bioactivity of the nuclear transcription factors. Results The mRNA and protein expression of GH could be promoted significantly by Tax. Relative to the TaxN cells, the transcriptional activity of GH was significantly increased about 6.37 times in TaxP cells(P＜0.05). Overexpression of GH can increase the activity of NF-κB about 1.7 times in TaxP cells (P＜0.05). Conclusion GH maybe involve in adult T-cell leukemia(ATL) through activating NF-κB.