Influences of recombinant human HMGB1 on the expression of HMGB1-related receptors in HTLV-1 infected MT2 cells

Abstract

Objective To investigate the influences of recombinant human high mobility group protein 1 (rhHMGB1) on the expression of HMGB1-related receptors in Human T-cell leukemia virus type 1 (HTLV-1) infected MT2 T cells.Methods rhHMGB1 was added to HTLV-l-positive MT2 cells at a final concentration of 1 μg/ml.Equal volume of PBS was used to set up the control.After 24 h of culture,the expression and distribution of surface molecules including advanced glycosylation end products (RAGE),T cell immunoglobulin mucin 3 (TIM-3) and toll like receptor 4 (TLR4) were detected by flow cytometry,Western blot and immunofluorescence.Resulls The results of flow cytometry analysis showed a decreased expression of RAGE,but a significantly increased expression of TLR4 (P＜0.05) on MT2 cells stimtlated by 1μg/ml rhHMGB1,as compared with control group.The expression of RAGE and TLR4 among total cellular proteins and cytoplasmic proteins were significantly increased (P＜0.05),while the expression of TIM-3 showed no significant change as indicated by Western Blot.The immunofluorescence staining demonstrated that the fluorescence intensity of TLR4 and RAGE were increased,while the fluorescence intensity of TIM-3 showed no change upon rhHMGB1 treatment.Furthermore,TLR4 and TIM-3 were mainly distributed on the cell membrane,while RAGE was found in the cytoplasm.Conclusion Recombinant human HMGB1 can enhance the expression of RAGE and TLR4 in HTLV-1-infected T cell line MT2. Key words: Human T-cell leukemia virus type 1; High mobility group box 1; HMGB1-related receptor