Fig. 1

Shikonin-treated 4 T1 tumor cell lysate effectively activates DCs that in turn induce T-cell proliferation in vitro. SK-TCL or Dox-TCL samples were prepared from transgenic Luc2-labelled 4 T1 cells that were treated with shikinon or doxorubicin at 5 μM for 24 h. Mouse bone marrow-derived DCs were then treated with Naive-, SK- or Dox-TCL samples and used as stimulator cells. Splenic CD4⁺ and CD8⁺ T cells were collected from syngeneic mice and employed as responder cells. Proliferation activities of a CD4⁺ and b CD8⁺ T cells were analyzed by mixed lymphocyte reaction (MLR) assay. Ratios of stimulator to responder cells were set between 1:1000 and 1:5. T-cell proliferation activity is represented as fold change over the control (T cells only). Data represent the mean ± SD of three biological replicates, and an independent experiment showed similar results