Influence of extracellular HMGB1 on the virus replication of HTLV-1 infected T cells

Abstract

Objective To investigate the influence of extracellular high mobility group box 1 (HMGB1) on viral replication in HTLV-1 infected T cells.Methods HMGB1 in culture supernatants of adult T-cell leukemia virus 1 (HTLV-1) virus-negative cell:Jurkat,MOLT4 cells and HTLV-1 virus-positive cells:MT2,MT4,was detected by ELISA;The HTLV-1 long terminal repeat reporter gene (pHTLV-1-LTR-luc) was transfected into MT2 cells by Tfx-50-mediated transfection,and 0.25,0.50,0.75 μg/ml of HMGB1 polyclonal antibody(HMGB1 PcAb) and its isotype control rabbit IgG antibodies,0.03,0.1,0.3 μg/ml rhHMGB1 and its control PBS,were added into culture supernatant respectively,then luciferase activity was detected after 48 h;Similarly,0.25 μg/ml HMGB1 PcAb and the isotype control antibody,0.3 μg/ml rhH-MGB1 and the control PBS were added to the culture supernatant of MT2 cell,the viral gene,pol1,pol2,gag,env,etc,were performed by real-time PCR.Results Culture supernatant HMGB1 levels has no significant difference between HTLV-1 positive cells MT2 and MT4 and the other two virus-negative T cell lines;Compared with isotype control antibody group,the culture supernatant,to which is added 0.25 μg/ml HMGB1 PcAb,can significantly inhibit the HTLV-1-LTR transcriptional activity and suppress the expressions of the viral gene pol1,pol2,gag,env.Compared with the control PBS,0.3 μg/ml rhHMGB1 significantly promotes the transcriptional activity of the HTLV-1-LTR and the expressions of the viral gene pol1,pol2,gag,env.Conclusion The extracellular HMGB1 can promote viral replication of HTLV-1 infected T cells. Key words: Human T-cell leukemia virus type 1; High mobility group box 1; Viral replication