T cells response following stimulation by DRibbles or cell lysates. (A) The ubiquitinated proteins and pp65 proteins contained in the cell lysate and DRibbles were examined by western blot. Lysates and DRibbles extracted from cell lines treated with bortezomib contained more ubiquitinated proteins than those from non-treated cells (left). The pp65 protein was detected in the lysates and DRibbles extracted from the UbiLT3 pp65 cell line. The pp65 DRibbles collected from the bortezomib-treated UbiLT3 pp65 cell line contained more 148Kd pp65 protein compared with the other groups (right). Data are representative of 3 independent experiments. (B,C) PBMCs were stimulated by DRibbles and cell lysates at the following doses: 3ug/ml, 10ug/ml and 25ug/ml. The percentage of IFN-γ+CD8+
(B) and IFN-γ+CD4+ cells (C) were calculated by flow cytometry. Percentages of IFN-γ+ T cells are shown as mean ± SEM. Data are representative of results from 3 independent experiments. (D) Dot plots at the antigen dose of 25ug/ml.