Objective: To observe the effect of autologous dendritic cells (DC) on positive Philadelphia (Ph+) chromosome cells of Chronic Myeloid Leukemia (CML) in vitro.

Methods: DCs and T cells extracted from the peripheral blood mononuclear cell (PBMNC) of 4 CML patients with Ph+ chromosome in chronic phases were amplified in a special liquid culture system. The survival rates of the Ph+ chromosome cells in the bone marrow mononuclear cells (BMMNC) and the K562 cells were determined by the conventional chromosome assays, after About 3 x 10(5)/ml DC incubating with autologous T cells activated by IL-2 or DCs plus IL-2 for 6 hours.

Results: About 3 x 10(5)/ml DC per 2 x 10(6)/ml PBMNC were produced. The cytotoxic effect of the T cells activated by DCs plus IL-2 on the autologous Ph+ chromosome cells was significantly greater than those activated by IL-2 (P < 0.001). The clearance activity of the DC activated T cells on the autologous CML Ph+ chromosome cells was stronger than on the K562 cells (P < 0.001).

Conclusions: The DCs-activated autologous T cells can effectively inhibit the Ph+ chromosome cells. The cytotoxic effect of the autologous T cells activated by the DCs on the Ph+ chromosome cells could be MHC-restricted.