Objective: To culture dendritic cells (DCs) from human acute myeloid leukemia (AML) cells, and to observe the cytotoxic effect of the T lymphocytes that are activated by DCs pulsed with leukemic antigen peptides (LAP) or LAP-heat shock protein 90 (HSP90) on autologous AML cells.
Methods: Mononuclear cells (MNC) were isolated from peripheral blood (PB) and bone marrow (BM) of patients with AML by density gradient centrifugation; DCs were induced from MNC of PB in a special culture system including recombinant human granulocyte-monocyte colony stimulating factor (rhGM-CSF), interleukin-4 (rhIL-4) and tumor necrosis factor-alpha (TNF-alpha) for 7-14 days. These DCs were identified by morphology and immunophenotype studies; LAP were obtained by repeatedly freezing and thawing AML cells respectively. DCs were pulsed with LAP and LAP-HSP90 compounds respectively. The cytotoxity of T lymphocytes activated by antigen pulsed DCs on autologous AML cells was measured in vitro by the lactate dehydrogenase-release assay.
Results: After 7-14 days' culture, (6-11) x 10(4) DCs were obtained from 1 x 10(6) MNC of PB in 3 AML cases. The cytotoxity rates of T lymphocytes, from 3 AML cases, activated by DCs pulsed with LAP and LAP-HSP90 compounds were (35.33+/-9.04)% and (62.07+/-8.29)% respectively.
Conclusion: Effective cytotoxity of T lymphocytes to the autologous leukemia cells can be induced by DCs pulsed with LAP and LAP-HSP90 compounds respectively, but the effectiveness induced by the latter is more powerful than that induced by the former.